[House Hearing, 112 Congress]
[From the U.S. Government Printing Office]



 
                         [H.A.S.C. No. 112-154] 

                    F-22 PILOT PHYSIOLOGICAL ISSUES 

                               __________

                                HEARING

                               BEFORE THE

              SUBCOMMITTEE ON TACTICAL AIR AND LAND FORCES

                                 OF THE

                      COMMITTEE ON ARMED SERVICES

                        HOUSE OF REPRESENTATIVES

                      ONE HUNDRED TWELFTH CONGRESS

                             SECOND SESSION

                               __________

                              HEARING HELD

                           SEPTEMBER 13, 2012


                                     
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              SUBCOMMITTEE ON TACTICAL AIR AND LAND FORCES

                 ROSCOE G. BARTLETT, Maryland, Chairman
FRANK A. LoBIONDO, New Jersey        SILVESTRE REYES, Texas
JOHN C. FLEMING, M.D., Louisiana     MIKE McINTYRE, North Carolina
TOM ROONEY, Florida                  JIM COOPER, Tennessee
TODD RUSSELL PLATTS, Pennsylvania    NIKI TSONGAS, Massachusetts
VICKY HARTZLER, Missouri             LARRY KISSELL, North Carolina
JON RUNYAN, New Jersey               MARTIN HEINRICH, New Mexico
MARTHA ROBY, Alabama                 BILL OWENS, New York
WALTER B. JONES, North Carolina      JOHN R. GARAMENDI, California
W. TODD AKIN, Missouri               MARK S. CRITZ, Pennsylvania
JOE WILSON, South Carolina           KATHLEEN C. HOCHUL, New York
MICHAEL TURNER, Ohio                 JACKIE SPEIER, California
BILL SHUSTER, Pennsylvania
DOUG LAMBORN, Colorado
                John Sullivan, Professional Staff Member
                  Doug Bush, Professional Staff Member
                     Scott Bousum, Staff Assistant



                            C O N T E N T S

                              ----------                              

                     CHRONOLOGICAL LIST OF HEARINGS
                                  2012

                                                                   Page

Hearing:

Thursday, September 13, 2012, F-22 Pilot Physiological Issues....     1

Appendix:

Thursday, September 13, 2012.....................................    35
                              ----------                              

                      THURSDAY, SEPTEMBER 13, 2012
                    F-22 PILOT PHYSIOLOGICAL ISSUES
              STATEMENTS PRESENTED BY MEMBERS OF CONGRESS

Bartlett, Hon. Roscoe G., a Representative from Maryland, 
  Chairman, Subcommittee on Tactical Air and Land Forces.........     1
Reyes, Hon. Silvestre, a Representative from Texas, Ranking 
  Member, Subcommittee on Tactical Air and Land Forces...........     3

                               WITNESSES

Cragg, Clinton H., Principal Engineer, National Aeronautics and 
  Space Administration (NASA) Engineering and Safety Center......    11
Lyon, Maj Gen Charles W., USAF, Director of Operations, 
  Headquarters Air Combat Command, U.S. Air Force................     7
Martin, Gen Gregory S., USAF (Ret.), Aircraft Oxygen Generation 
  Study Chair, USAF Scientific Advisory Board....................     4

                                APPENDIX

Prepared Statements:

    Bartlett, Hon. Roscoe G......................................    39
    Cragg, Clinton H.............................................    99
    Lyon, Maj Gen Charles W......................................    60
    Martin, Gen Gregory S........................................    46
    Reyes, Hon. Silvestre........................................    42

Documents Submitted for the Record:

    [There were no Documents submitted.]

Witness Responses to Questions Asked During the Hearing:

    Ms. Speier...................................................   105

Questions Submitted by Members Post Hearing:

    Mr. Bartlett.................................................   109
    Mr. Loebsack.................................................   116
    Mr. Runyan...................................................   113
    Ms. Speier...................................................   115
                    F-22 PILOT PHYSIOLOGICAL ISSUES

                              ----------                              

                  House of Representatives,
                       Committee on Armed Services,
              Subcommittee on Tactical Air and Land Forces,
                      Washington, DC, Thursday, September 13, 2012.
    The subcommittee met, pursuant to call, at 10:02 a.m., in 
room 2118, Rayburn House Office Building, Hon. Roscoe G. 
Bartlett (chairman of the subcommittee) presiding.

OPENING STATEMENT OF HON. ROSCOE G. BARTLETT, A REPRESENTATIVE 
FROM MARYLAND, CHAIRMAN, SUBCOMMITTEE ON TACTICAL AIR AND LAND 
                             FORCES

    Mr. Bartlett. The hearing will come to order. The 
subcommittee meets today to receive testimony on F-22 pilot 
physiological issues which have resulted in reported hypoxia-
like events by F-22 pilots over a period of several years.
    The committee's concerns include the impacts of these 
physiological issues to the pilots and operational capability 
of these valuable aircraft, as well as the ultimate cost and 
time required to implement the recommendations that have been 
made to modify the F-22 life support system.
    The committee also remains concerned that after all of the 
study of the issue, we need to understand what the level of 
confidence is that the cause or causes of the F-22 
physiological issues are fully known.
    From 2003 to April 2008, there were 6 F-22 physiological 
issues, but between April 2008 and January 2011, that number 
had doubled to 12. As a result of this, the Air Force Commander 
of Air Combat Command restricted the F-22's maximum flight 
attitude to 25,000 feet and directed a safety investigation 
board to review the F-22's oxygen system.
    In May of 2011, the Secretary of the Air Force directed the 
Scientific Advisory Board to gather information and make 
recommendations to address concerns relative to the F-22 life 
support system. From May to September of last year, the F-22 
fleet stood down as a result of an upward trend in reports of 
physiological incidents. The Scientific Advisory Board [SAB] 
completed its work in January of this year but did not 
determine a cause for the F-22 pilot physiological problems. 
However, the board did make findings and recommendations and 
concluded that either the supply or the quality of the oxygen 
is contributing to the F-22 pilots' hypoxia-like symptoms.
    Air Combat Command established a Life Support System Task 
Force, which continued to examine both the issues of supply and 
quality of oxygen in the F-22. On April 23, 2012, the National 
Aeronautics and Space Administration, NASA, accepted a request 
from the Air Combat Command to form an independent 
investigative team to review Air Combat Command's investigative 
process, ongoing root cause analysis, and the F-22 life support 
system as a whole to determine potential vulnerabilities to the 
pilot.
    On July 24th, the Department of Defense announced that Air 
Combat Command had determined that the root cause of the F-22 
pilot physiological issues is the supply of oxygen delivered to 
the pilots, not the quality of oxygen delivered to the pilots.
    To correct the supply issue and reduce the incidence of 
related hypoxia-related events, the Air Force has made two 
changes to the aircraft's cockpit life support system. First, 
the Air Force has increased the volume of air flowing to pilots 
by removing a filter that was installed as a part of the 
investigation to determine whether there were any contaminants 
present in the oxygen system. Second, the Air Force will 
replace a valve in the upper pressure garment worn by pilots 
during high-altitude missions. The upper pressure garment is 
designed to provide counterpressure to assist pilots' breathing 
and to help counteract the effects of G-forces. The garment 
valve was causing the vest to inflate and remain partially 
inflated under conditions where it was not designed to do so, 
thereby causing breathing problems for some pilots. Oxygen 
contamination was ruled out as potential cause.
    The Air Force is also exploring ways to improve the oxygen 
delivery hose and its physical connections.
    In the interim, the F-22 is under a temporary altitude 
limit of 44,000 feet. Since the F-22 returned to flying status 
in September of 2011, there have been 11 hypoxia incidents 
where the incidents were initially reported as cause unknown. 
The Air Force continues to investigate these incidents, and as 
of late July, less than half of those were still unresolved.
    There have been no cause unknown hypoxia incidents in the 
F-22s since March of 2012.
    From fiscal year 2002 to May 2011, the Air Force reports an 
incidence rate of 13 hypoxia events per 100,000 hours compared 
to 7.5 in the F-16, and 1.8 in the F-15E, and 6.6 in the F-18E, 
F and G, over roughly the same period.
    I know from personal experience as a scientist working with 
these issues before I came to Congress that the Air Force faced 
a difficult problem in determining the root cause of these 22 
pilot hypoxia-like events because symptoms of hypoxia and 
hypocapnia, also know as hyperventilation, are very difficult 
to distinguish. Indeed, pilot concerns about hypoxia will 
frequently result in hyperventilation, imperceptible to the 
pilot, which will produce hypoxia-like symptoms, eliciting even 
more hyperventilation, a vicious cycle.
    A significant amount of effort has gone into solving the F-
22 physiological issues, but much more needs to be done. 
Recommendations of the Air Force Scientific Advisory Board's 
Oxygen Generation Study Group needs to be implemented. The Air 
Force Air Combat Command Life Support Systems Task Force needs 
to complete its report and provide its final recommendations.
    Additionally, NASA's Engineering and Safety Center needs to 
complete final report and provide its recommendations. The 
committee expects the Air Force to keep Congress up to date on 
the status of all of these reports and recommendations.
    To address the F-22 physiological issues, we have asked the 
three key leaders involved in this project to testify today: 
Retired Air Force General Gregory S. Martin, Chairman of the 
Air Force Scientific Advisory Board Quick Look Study on 
Aircraft Oxygen Generation.
    General Martin, welcome back.
    Major General Charles Lyon, Director of Operations for the 
Air Combat Command. General Lyon leads the F-22 Life Support 
System Task Force.
    Finally, Mr. Clinton H. Cragg, principal engineer at NASA's 
Engineering and Safety Center. Mr. Cragg leads NASA's 
independent investigative team, which has reviewed Air Combat 
Command's F-22 processes and analyses.
    Gentlemen, we thank you all for your service to our 
country.
    Before we begin, let me call on the ranking member of the 
subcommittee, Mr. Reyes, for his opening remarks.
    [The prepared statement of Mr. Bartlett can be found in the 
Appendix on page 39.]

STATEMENT OF HON. SILVESTRE REYES, A REPRESENTATIVE FROM TEXAS, 
  RANKING MEMBER, SUBCOMMITTEE ON TACTICAL AIR AND LAND FORCES

    Mr. Reyes. Thank you, Mr. Chairman.
    And let me add my welcome to you this morning, gentlemen.
    From a personal perspective, I want to thank the Chairman 
because as a scientist, he was able to explain some of these 
very difficult technical issues with the problem that we have 
been wrestling with now with the oxygen system of the F-22.
    So, Mr. Chairman, I wanted to thank you publicly for--on 
this committee, for having the expertise to be able to do that, 
and thank you for your leadership as well.
    Today's hearing on the F-22 will cover many technical 
issues, as I mentioned, that have been associated with the F-
22's pilot life support system. On balance, I am pleased with 
the level of effort that the Air Force has put into this 
investigation. It is clear that the current senior Air Force 
officials have taken this issue very seriously and have put in 
place the necessary resources and organizations needed to 
identify the problem and eventually to get to a place where we 
fix this problem.
    The scale of the testing and the evaluation effort for a 
tactical fighter aircraft is, from my view point, 
unprecedented. Rather than staying in a defensive posture, the 
Air Force reached out to other agencies and other military 
services for additional expertise and for advice. Based on the 
extensive work done by the Air Force and other DOD [Department 
of Defense] agencies, I am cautiously optimistic that the Air 
Force has indeed identified the primary causes of the hypoxia 
problems with the F-22, has identified fixes that, from a 
layman's perspective, seemed to make sense.
    The next step is ensuring that the fixes identified are 
funded and installed as rapidly as possible. The United States 
clearly needs the F-22 to deter our enemies and to provide 
critical capabilities if we go to war. Despite Congress passing 
a long-term continuing resolution for defense spending, I 
personally want to ensure that efforts to fix the F-22 problems 
can continue at full speed.
    So understanding the F-22's problems and how to fix them is 
one aspect of today's hearing and a very important one. 
However, the larger issue that I hope today's hearing will 
touch on is how this situation occurred in the first place, and 
how we avoid similar mistakes going forward.
    As far as the cause of the F-22's problems, my overall 
impression from the testimony that we have received and other 
information provided to our committee is that the main problems 
with the F-22 were human failures of judgment and not technical 
failures.
    One issue that appears to have gone wrong was a basic 
design of the aircraft's life support system. The F-22 is the 
most capable and, I should add, expensive fighter aircraft ever 
developed. The F-22 also operates at higher altitudes and in a 
more demanding performance envelope, perhaps more than any 
other fighter in the history of this country. Given these two 
factors, a cost per plane of more than $140 million and a 
unique flight environment, it is very surprising that it was 
designed, again from a layman's perspective, with--designed 
without a sophisticated backup oxygen system or even enough 
instrumentation to let the pilot know that he wasn't getting 
oxygen in time to actually do something about it.
    So one question that confronts the subcommittee is, how did 
that happen? Why did the Air Force design and build such a 
sophisticated aircraft with such a relatively unsophisticated 
pilot oxygen support system?
    In addition, why wasn't this issue identified during 
testing of the aircraft? That is normally when serious design 
issues are identified for future fixes. But that doesn't seem 
to have been the case with the F-22.
    We are going to get a lot of information today, but in 
particular, I look forward to hearing from the Air Force 
witnesses and, again, welcome, how they think we got to this 
point and how we can avoid similar problems with other aircraft 
in the future.
    And with that, Mr. Chairman, I want to yield back to you.
    [The prepared statement of Mr. Reyes can be found in the 
Appendix on page 42.]
    Mr. Bartlett. Thank you very much.
    Without objection, all witnesses' prepared statements will 
be included in the hearing record.
    General Martin, please proceed with your opening remarks. 
You will be followed by General Lyon and Mr. Cragg.

   STATEMENT OF GEN GREGORY S. MARTIN, USAF (RET.), AIRCRAFT 
 OXYGEN GENERATION STUDY CHAIR, USAF SCIENTIFIC ADVISORY BOARD

    General Martin. Thank you, Mr. Chairman.
    Chairman Bartlett and Ranking Member Reyes and other 
distinguished members of this committee, I am honored to be 
here today representing the members of the Air Force Scientific 
Advisory Board Study Panel on Aircraft Oxygen Generation 
Systems.
    During my remarks and during my responses to any questions 
that I receive, I will try to answer the questions as I believe 
the members of the study panel would answer them, as opposed to 
my own personal views.
    The onboard oxygen generation system [OBOGS] on the F-22 is 
very similar to other onboard oxygen generation systems that we 
have on many fighter aircraft. And they were designed to reduce 
the servicing, logistic support and safety--and increased 
safety considerations. The F-22 aircraft is equipped with such 
a system to provide breathing air to the pilot, and this system 
usually, in the F-22 as well as the other aircraft, will take 
bleed air off of the engine, concentrate it into a higher level 
of oxygen and then match that amount of oxygen to the breathing 
air, based on the cabin pressure and altitude.
    Beginning in 2008, as the chairman pointed out, the F-22 
began to experience a significantly higher rate of hypoxia-like 
incidents with unknown causes, as reported by the pilots. At 
that point, the Air Force initiated what I will refer to as a 
four-tier approach to finding the root cause for these 
unexplained physiological incidents. The first tier was a 
collaborative effort between the F-22 system program office, 
the prime contractor and its key subcontractors responsible for 
the components of the F-22 life support system, and the normal 
Air Force safety investigation structure. So that collaborative 
effort started a process we have come to know as the Root Cause 
and Corrective Action [RCCA] analysis process that has 
continued for the last 4\1/2\ years.
    The second tier was initiated after preliminary results of 
the tragic fatal F-22 mishap that occurred in November of 2010. 
When that mishap was out-briefed to the senior leadership in 
January of 2011, the Air Combat Command established a Class E 
safety investigation mishap board. That board was chaired by an 
Air Force Major General, and it was chartered to review all F-
22 reported hypoxia-like incidents. So, in conjunction with the 
RCCA team, or the Root Cause and Corrective Action Analysis 
Team, this safety investigation team developed and implemented 
a multitude of tests and challenges to each of the F-22s life 
support system components.
    At that time, the F-22 flight operations were limited to 
25,000 feet and the pilots were directed to fly in the maximum 
oxygen production mode, known as max. These directions were 
provided to minimize the opportunity for any of the crews to be 
exposed to an environment that could cause hypoxia-like 
symptoms, so lower altitude and use of 100 percent oxygen 
direction was given to prevent or preclude future hypoxia-like 
incident. Nonetheless, there was an increase in the number of 
hypoxia-like events. And after two troubling incidents in May 
of 2011, the Air Force grounded the fleet of F-22 aircraft. At 
that point, the Safety Investigation Board, which had been 
unable to determine a failure mode that might lead to the 
hypoxia-like events, recommended that the Air Force modify one 
of its test aircraft with a specialized array of sensors and 
then execute a carefully developed series of flight test 
profiles to determine if the root cause could be assessed in 
the dynamic flight environment as opposed to the ground testing 
that had been done to that point.
    Further, as a part of their investigation, the Safety Board 
determined there were decisions made during the engineering, 
manufacturing and development phase of the F-22's development 
that should be reviewed from a broader perspective, and they 
recommended a broad area review of the F-22 program be 
conducted. So, in June of 2011, the Secretary of the Air Force 
and the Chief of Staff of the Air Force tasked the United 
States Air Force Scientific Advisory Board to perform a quick-
look study on aircraft oxygen generation systems and to cover 
three areas: First, continue the ongoing efforts to determine 
the root cause, to include gathering data during dynamic in-
flight testing, full reviews of both the life support equipment 
and the aircraft's potential for passing contaminants into the 
cockpit and/or the breathing air, and finally, to better 
understand the similarities and differences between the F-22 
oxygen generation system and other military aircraft; second, 
to better understand the conditions that would create hypoxia-
like symptoms at altitudes not normally associated with 
hypoxia, along with an evaluation of the guidance associated 
with breathing air standards and the human response to 
operating in the F-22's extraordinary envelope with less than 
90 percent supplied oxygen; third, to review the policies, 
processes and procedural changes that occurred during the F-
22's development and fielding phase to evaluate the 
implications with respect to design limitations, risk analysis, 
program execution and the acquisition workforce.
    The study began in June of 2011, with interim status 
reports provided to Secretary and the Chief until the final 
briefing was approved by the entire Scientific Advisory Board 
and delivered to the Secretary and the Chief on the 24th of 
January 2012. This activity actually represents the third tier 
of effort in determining root causes.
    It is important to note that SAB study panel recognized 
from some initial statistical analysis that it was quite likely 
that in the initial flight test profiles conducted during the 
summer of 2011, that we may not determine the root causes in 
that limited sample of flight. With that in mind, it became 
clear that it would need to develop or help the Air Force 
develop an appropriate risk-mitigation procedure to allow the 
F-22 fleet to return to flight operations in a safe mode that 
would provide the Nation with its critical combat capabilities 
while at the same time offering Air Force--the Air Force the 
ability to collect and analyze the voluminous amount of data 
that would be collected during these flights and to continue 
their investigation in determining root causes for the 
unexplained physiological incidents.
    As a result, the SAB study manual was able to develop a 
protocol of aircraft inspections, crew training, crew 
protection devices and procedures, along with a specific series 
of incident response protocols to assist the Air Force in 
zeroing in on the root causes or root causes. With that in 
mind, the Air Force chose to resume F-22 flight operations in 
September 2011.
    Between that time and the AFSAB, or the Scientific Advisory 
Board's, out-brief to the Secretary and to the Chief in January 
2012, the AFSAB continued to assess and evaluate data from 
approximately 7,500 sorties. As a result of analyzing the 
emerging stream of data, the study panel completed its study 
effort and made recommendations to the Air Force leadership in 
third areas that would, one, in the near term, allow the Air 
Force to complete its root-cause analysis and safely return the 
F-22 to its full operational flight envelope; two, over the 
next several years, modify the aircraft and develop specific F-
22 tools to improve the margin of safety related to the F-22's 
entire life support system design and performance and develop 
procedures related to the human system's integration process 
that the Air Force uses to further explore the interaction 
between the human and the F-22 in all of its environment. They 
also directed that the Air Force take the lead in establishing 
comprehensive aviation breathing air standards applicable to 
the environments in which all of its aircraft would operate.
    The key to implementing the AFSAB study panel 
recommendations was determined to be the establishment of a 
task force to continue the data-gathering and analysis process 
initiated by the AFSAB study panel, while at the same time 
developing the implementation plans to finalize and close out 
the remaining recommendations. Standing up this task force, 
which has been directed by Major General Lyon, next to speak, 
represents the fourth tier of the Air Force's overall effort to 
find the root causes to the unexplained physiological 
incidents.
    As a final note, I would mention that the study panel did 
recommend a quarterly follow-up be established to review the 
process on completing the recommendations and that the AFSAB 
would be available for support, if required. To date, the task 
force has completed two quarterly follow-ups and presented 
their reports to the AFSAB. And their progress has been 
impressive.
    In summary, I believe this four-tier approach, coupled with 
the Air Force's request from NASA for an independent assessment 
of their process and their recommendations represents that the 
Air Force is dedicated to being thorough, credible and 
transparent in its approach to solving this difficult issue.
    This completes my initial statement, and I look forward to 
your questions.
    [The prepared statement of General Martin can be found in 
the Appendix on page 46.]
    Mr. Bartlett. Thank you very much.
    General Lyon.

    STATEMENT OF MAJ GEN CHARLES W. LYON, USAF, DIRECTOR OF 
  OPERATIONS, HEADQUARTERS AIR COMBAT COMMAND, U.S. AIR FORCE

    General Lyon. Chairman Bartlett, Ranking Member Reyes, 
distinguished members of the committee, thank you for the 
opportunity today to discuss an issue of great importance to 
the United States Air Force, the F-22 pilot physiological 
issue.
    Mr. Chairman, I would like to thank you for the steadfast 
leadership of this committee and to your members for their 
unwavering support and commitment to the men and women of the 
United States Air Force and the entire Department of Defense. 
This committee has helped ensure our men and women are equipped 
and resourced to meet the responsibilities in support of 
national security objectives at home and abroad over the years.
    The F-22 Raptor contributes significantly to our Nation's 
interest vital interest by providing air dominance when and 
where ordered to protect and enable the joint military force. 
Today, we have F-22s forward deployed to support the objectives 
of geographic combatant commanders in the Central Command, and 
Pacific Command areas of operations. This forward presence 
reassures our allies, enhances joint and coalition 
interoperability, and demonstrates our resolve for lasting 
global relationships.
    We also have continental United States based F-22s 
contributing to homeland defense, while the remainder of the 
fleet conducts combat-mission-ready training, formal 
replacement unit training and operational test and evaluation.
    The F-22's attributes, stealth, supercruise, 
maneuverability, and integrated avionics, ensure our ability to 
project power anywhere on the globe, including anti-access and 
area denial environments. Simply stated, the F-22 fleet, 
combined with complementary capabilities from our joint 
partners, allows us to kick down the door and enable joint 
operations in the most demanding environments that exist now 
and in the foreseeable future. The F-22's multi-mission 
capabilities allow us to seize the initiative, achieve air 
superiority, attack those who challenge us in the skies, and to 
defeat those who would challenge us from the ground. The F-22 
contributes significantly to protect the joint force from 
attack, while enabling the joint force to conduct offensive 
operations.
    The capabilities of the F-22 weapon system are compelling, 
but without the contributions of the men and women who fly, fix 
and support F-22 operations, the Raptor would never leave the 
ground. Flying high-performance fighter aircraft is not risk-
free. But the risk is measured against mission priorities and 
probabilities of success. Just as other airmen and members of 
the joint force accept risk in the conduct of their daily 
military duties, we accept risk in operating the F-22.
    To set the context for this issue's history, as the 
chairman said, F-22 fleet experienced six physiological 
incidents in our initial phases over a 5-year period. The 
number of incidents more than doubled in the next 3 years. The 
increased number of incidents in 2008 to 2011, the ambiguities 
and uncertainties at the time surrounding Captain Haney's 
November 2010 tragic and fatal mishap, and the unexplained 
nature of these incidents gave the Air Force grave concern, 
which prompted the fleetwide standdown in May 2011.
    Although the total percentage of physiological incidents at 
the time of the standdown represented less than 0.1 percent of 
all sorties flown to date, that wasn't good enough, and it did 
not meet our service established safety standards. The risk to 
the safety of our airmen posed by uncertainty and ambiguity 
exceeded our threshold.
    During the standdown, the Air Force expanded analytic 
capabilities beyond the use of normal governmental resources to 
include additional expertise from the public and private 
sectors. After months of research, testing, and analysis, 
General Martin's study group provided a set of recommendations 
to the Air Force September of last year. This put us on the 
path to safely return the F-22 fleet to flight operations with 
an acceptable level of risk.
    The recommendations were reviewed and implemented with the 
F-22 fleet returned to flying just under a year ago, September 
21st, 2011. Between September 2011 and today, the Air Force has 
continuously analyzed the previously unexplained physiological 
incidents, implemented and adjusted risk-mitigation measures, 
and incorporated corrective actions to enhance the safety of 
the F-22 Raptor fleet.
    General Martin's study group completed their investigative 
actions in January of this year. Following General Martin's 
presentation to Air Force leaders, the Secretary of the Air 
Force formed the F-22 Life Support Systems Task Force, led by 
me, to continue this analytic effort and implement corrective 
actions. Our integrated, collaborative, multi-service, cross-
functional, government/industry team approach permitted an 
increased breadth of experience, enhanced scope of knowledge 
and provided additional and partial expert analysis, which was 
critical in the determination of root causes. The task force 
has considered the inputs, findings and recommendations of the 
previously convened F-22 Safety Investigation Boards, 
Scientific Advisory Board and Lockheed Martin's Root Cause and 
Corrective Analysis Team. We have integrated their findings, 
continued the investigative process, and drawn conclusions that 
could not have been reached without the benefit of this 
collaborative approach.
    The previously unexplained F-22 physiological incidents 
were the result of multifactorial combinations. The trend over 
time has eliminated system-specific factors related to oxygen 
delivery system components. During our analysis timeframe, 
Major Dr. Marsha Mitchum, seated behind me, an F-22 flight 
surgeon at Joint Base Langley-Eustis, conducted independent 
research with Duke University and the Naval Surface Warfare 
Center in Panama City, Florida. Through her efforts and 
coordination, the naval experimental dive unit became involved 
to offer an assessment on life support issues and breathing 
devices. This research opened a door for new analysis that had 
not been addressed to this point in our Air Force investigative 
process. This would turn out to be a decisive moment for F-22 
investigative efforts.
    We convened an F-22 Restrictive Breathing Working Group at 
Langley in April of this year. The task force facilitated this 
session, lead by Lieutenant Colonel Jeff Hawkins, seated behind 
me, from the First Fighter Wing, an F-22 pilot. This group 
consisted of F-22 pilots, engineers, medical and safety 
professionals from the Air Force, Air Force Combat Command, Air 
Force Materiel Command; from the Navy, both the Experimental 
Dive Unit, their Surface Warfare Center; Naval Air Systems 
Command [NAVAIR] from NASA, Wyle Labs, Lockheed Martin and 
Boeing, an impressive group of professionals gathered together 
to work this issue.
    Additionally, the task force sought NASA's assistance to 
review our post-incident protocols and, if warranted, recommend 
enhanced procedures with a greater emphasis on integrated life 
support systems and cabin pressurization systems analysis. 
Concurrently, we requested that NASA form an independent team 
to review our investigative process in the entire F-22 life 
support system to determine potential vulnerabilities to the 
pilot.
    The NASA Engineering and Safety Center [NESC] provided that 
team, lead by Mr. Clint Cragg, sitting here to my left here 
today. I would like to thank Mr. Cragg and his team for their 
unique insight and contributions to our efforts. Two weeks ago, 
Mr. Cragg presented his findings and recommendations to me for 
incorporation in our analysis.
    While corroborating much of what we had researched, the 
team also presented additional measures for our consideration.
    The task force is confident that data derived from General 
Martin's group hypothesis one, oxygen quantity, describes the 
major contributors to the previously unexplained physiological 
incidents reported by F-22 pilots over the past few years. The 
task force is confident that the hypothesis two, oxygen 
quality, is not the root cause of previously unexplained 
physiological symptoms reported by F-22 pilots and ground crew.
    Systemic factors in the life support system, such as the 
Combat Edge upper pressure garment and the C2A1 filter 
functionalities, have been identified, removed and corrective 
action is underway. We have reduced the potential negative 
affects created by high oxygen concentration levels produced by 
the OBOGS through cockpit selectable oxygen sittings.
    Human factors at two F-22 operating locations were 
contributory. We have communicated findings and corrective 
actions to the community. This communication has reduced the 
ambiguity and uncertainty, while significantly increasing pilot 
and ground crew confidence in the F-22's life support systems.
    Mr. Chairman, we have more work ahead as we transition to 
normal F-22 flight operations. The path to resuming normal 
flight operations hinges on the successful development, 
testing, and fielding of the modified Combat Edge upper 
pressure garment valve. This modification will successfully 
integrate the key components of the F-22 life support system to 
ensure adequate oxygen flows to the pilot, while providing 
protection in the high-altitude and high-G environments where 
the F-22 flies. We expect this modification to be fielded by 
the end of 2012.
    I have had the opportunity to present task force interim 
findings, recommendations, and corrective actions to Department 
of Defense and Department of the Air Force senior leaders 
throughout this investigation. Department leaders have 
expressed keen interest to fixing the F-22's life support 
system vulnerabilities, to maximize the safety of the men and 
women who operate and maintain this aircraft, and have provided 
us the required resources and support to bring this issue to 
conclusion. The fielding of the automatic backup oxygen system 
will provide additional protection to F-22 pilots while flying 
at high altitude and under the most demanding oxygen delivery 
system scenarios that can be envisioned for the F-22 lifecycle.
    We expect the first operation aircraft will be modified in 
January 2013, the first operational squadron complete by the 
spring of 2013, and the entire fleet complete by mid 2014. We 
are certain the F-22 cockpit and surrounding workspace is a 
safe, effective place to operate, but the Air Force is an 
organization that is built on the foundation of innovation, 
self-improvement, and ingenuity. Continuous process 
improvements will ensure the safety of the F-22 workforce now 
and in the future.
    To date, since we resumed flight operations last September, 
we have flown nearly 20,000 sorties, totalling over 25,000 
hours, while encountering 11 previously unexplained in-flight 
incidents and 6 ground-related physiological incidents. None of 
these incidents have resulted in the loss of life, loss of 
aircraft control, nor lingering effects for our pilots and 
ground crews. Importantly, we have not encountered an 
unexplainable incident since March 8 of this year. Since that 
time, we have flown more than 10,000 sorties, totalling over 
13,000 hours, without incident. The trend is on a positive 
vector not seen in years.
    There will be physiological incidents in the future. The 
harsh high-altitude, high-G environment is extremely demanding, 
and our pilots are aware of those demands. We encounter 
physiological incidents in all high-performance aircraft--it is 
a fact of life--due to the demands placed on our air crew. The 
measures taken by the Air Force, in my opinion, will reduce the 
incident rate significantly and over time bring the F-22 
incident rates in line with comparable high-performance 
aircraft. The Air Force is committed to implementing these 
changes to return the F-22 to normal operations, thus 
significantly contributing to our Nation's vital interests by 
providing air dominance when and where ordered to protect and 
enable the joint U.S. military force. The Air Force will 
continue to leverage lessons learned throughout this 
investigative process, and will invest in characterizing and 
understanding the high-performance aircraft environment to 
optimize pilot performance, not only in the F-22 but in all 
current and future weapon systems.
    Mr. Chairman, I look forward to answering your questions.
    [The prepared statement of General Lyon can be found in the 
Appendix on page 60.]
    Mr. Bartlett. Thank you.
    Mr. Cragg.

  STATEMENT OF CLINTON H. CRAGG, PRINCIPAL ENGINEER, NATIONAL 
  AERONAUTICS AND SPACE ADMINISTRATION (NASA) ENGINEERING AND 
                         SAFETY CENTER

    Mr. Cragg. Chairman Bartlett, Ranking Member Reyes, members 
of the subcommittee, thank you for this opportunity to discuss 
the NASA Engineering and Safety Center's independent assessment 
of the F-22 life support system. I am honored to be serving as 
the lead of this NESC team.
    The NESC performs independent testing, analysis and 
assessments to help address some of NASA's tougher challenges.
    We can draw upon technical experts from all 10 NASA 
centers, industry academia and other government agencies. This 
allows us to bring the country's best experts to bear on 
problems and challenges of NASA programs.
    In April 2012, Major General Lyon requested NASA's 
assistance in their efforts to determine the cause of the 
hypoxia-like symptoms experienced by some F-22 pilots. NASA was 
requested to review current post-incident protocols and 
recommend enhanced procedures and also review the current 
investigative process, ongoing root cause analysis and the F-22 
life support system as a whole.
    The NESC assembled a team that included two NASA flight 
surgeons, two NASA human factor experts, an EPA [Environmental 
Protection Agency] forensic chemist, an industry oxygen 
generator system expert and several specialized NASA life 
support systems engineers.
    In the course of this investigation, the team reviewed data 
from multiple sources, visited manufacturing sites and F-22 
bases and held numerous discussions with knowledgeable 
personnel. The NESC team's findings and recommendations are 
based on this data and not on an exhaustive review of all F-22 
documentation.
    The NESC team concurs with the Air Force that the F-22 
incidents can be attributed to several factors: One, the high 
concentrations of oxygen at lower altitudes; two, the 
inevitable acceleration which compounds the effects of high 
oxygen; three, restricted breathing due to the inappropriate 
inflation of the upper pressure garment; and four, contribution 
of uncharacterized F-22 life support system vulnerabilities, 
such as pressure drops [across] components in the cockpit.
    The NESC team found a number of issues with the systems 
providing breathing air to the pilot. These systems are often 
treated as separate, but the events experienced are a result of 
the complex interactions of these systems, which, with the 
pilot included, are even more complex. Each flight puts extreme 
physiological demands on the pilot. The F-22 pilot community 
has come to consider a number of physiological phenomenon as a 
normal part of flying the Raptor, such as the difficulty in 
breathing and the Raptor cough. Acceptance of these phenomena 
as normal could be seen as a normalization of deviance.
    The NESC team found no evidence of a contaminant producing 
a toxic exposure. However, in any jet fighter environment, 
irritant compounds can be present. The F-22 has no effective 
filtration of breathing air or cabin air, which means irritant 
compounds could potentially enter the cockpit.
    The team found that the investigative process could have 
been more efficient. The F-22 task force was never given a 
directive that assigned the authority to conduct the 
investigation. They began with two narrow hypotheses and did 
not communicate well to all parties.
    The NESC team agrees with many of the Air Force's planned 
corrective actions and has identified a number of other areas 
for further consideration. These include both near- and long-
term recommendations. Many of the NESC near-term 
recommendations are actively being addressed by the Air Force. 
For example, the upper pressure garment and oxygen schedule are 
currently being modified. Post-incident protocols to establish 
standard case definitions and treatment guidance will require 
some additional effort.
    Longer-term recommendations include conducting end-to-end 
testing of the life support system, environmental control 
system and air crew flight equipment. We also recommend a 
fundamental reassessment of the requirements for the life 
support system in high-performance aircraft and a formal 
lessons-learned review of the Air Force-led investigation.
    In summary, the NESC team acknowledges that the F-22 Raptor 
is a high-performance aircraft that is expanding the capability 
of aircraft performance. The Air Force task force has made 
great strides this summer in understanding the complex, highly 
interrelated nature of this problem. The NESC's independent 
analysis supports the Air Force plan of corrective actions.
    Thank you, Mr. Chairman.
    [The prepared statement of Mr. Cragg can be found in the 
Appendix on page 99.]
    Mr. Bartlett. Thank you all very much for your testimony.
    Before we begin, I ask unanimous consent that 
nonsubcommittee members, if any, be allowed to participate in 
today's hearing after all subcommittee members have had an 
opportunity to ask questions.
    Is there an objection?
    Without objection, nonsubcommittee members will be 
recognized at the appropriate time for 5 minutes.
    As is my usual custom in these hearings, I will reserve my 
questions until the other subcommittee members have had an 
opportunity to ask theirs.
    Mr. Reyes.
    Mr. Reyes. Thank you, Mr. Chairman.
    Gentlemen, thank you for your testimony.
    Let me start off this morning with the first question 
dealing with what the long-term impact may be on pilots that 
have flown the F-22. The testimony indicates that since pilots 
have been flying the F-22 since 2005 with all the same 
equipment that has now been identified as causing the oxygen 
problems that we have discussed today and previously, over 
time, this means that hundreds of pilots have flown the F-22.
    So the questions I have are the following: What does the 
Air Force know about any long-term health impacts from flying 
the F-22? Second, has the Air Force gone back and examined the 
health records of former pilots to perhaps look for clues on 
the impact? And third, does the Air Force plan to continue to 
research this issue and to track the health of current pilots?
    So whoever wants to take those first three questions.
    General Martin. Mr. Congressman, let me address that if I 
could as the Air Force Scientific Advisory Board considered 
those questions and in its recommendations presented the Air 
Force with some thoughts about actions it should take.
    First of all, with respect to the long-term effects of 
flying the F-22, because the Scientific Advisory Board did not 
conclude its work with root causes, it was not sure at that 
point whether we had contamination getting into the breathing 
air, which could have some sort of irritation or effect on the 
pilot, or whether it was the interaction that General Lyon 
discussed between the percentage of oxygen, the upper pressure 
garment and breathing cycles associated with the work of 
breathing.
    But it had no knowledge of long-term effects by reviewing 
pilots who had flown the aircraft before. It had no indications 
that the phenomenon that they experienced in the airplane had 
long-term effects. But nonetheless it, before returning to fly 
in September of 2011, had a battery of physiological samples, 
specimens taken from all of the pilots that would fly so that 
had you a baseline record of those pilots, who, of course, had 
not flown for 4 or 5 months, a baseline of their medical data, 
and as recommended, the Air Force establish a medical registry 
for all who fly the F-22 in case, as time goes on, there are 
things that are discovered that we would want to be able to go 
back and reference the conditions that may have changed within 
those pilots.
    But from the Scientific Advisory Board perspective, they 
were unaware and were not able to find any long-term effects 
for those people that they questioned but did establish a 
medical baseline for those people who are currently flying the 
F-22.
    Mr. Reyes. Having said that, it is clear, at least from 
just a layman's perspective of reading and listening to your 
testimony, that individuals are affected differently by the 
same. And I point out by way of example that according to some 
of the testimony that I reviewed, that pilots were expected to 
recover quickly. In some cases, the expectation was within 
minutes or perhaps hours after flying and being affected by 
this. But in reality, some plots took days to recover. So is 
that--is that a cause of concern that we have one expectation 
and the reality is completely different?
    General Martin. I think it is safe to say that the 
interaction that General Lyon discussed manifests itself in 
different ways with different people. Particularly depending on 
their breathing style and their blood saturation level, 
hypoglycemia, things like that. But from the Air Force 
Scientific Advisory Board perspective, since we did not know we 
had not discounted the potential of contamination, we were not 
led down the track of G atelectasis and other interactions that 
General Lyon discussed as aggressively because we were pursuing 
both hypotheses; one dealt with whether they are getting enough 
air, and the other dealt with whether they are getting 
contamination. And we had six sub-hypotheses for each of the 
major two hypotheses that we were pursuing at the same time.
    And I'll let General Lyon speak to this, but as they 
continued the path of contamination and ultimately have stated 
that it is unlikely that there's a contaminant problem with the 
F-22 OBOGS system and focused more on the physiological effects 
of high concentrations of oxygen, interference with the upper 
pressure garment and perhaps some other physiological 
considerations, that area is one that I think General Lyon 
could address more completely than I.
    Mr. Reyes. General.
    General Lyon. Congressman Reyes, if I may, when we returned 
to flying last September, General Martin's group gave us a 
series of protocols to put in place, to take blood samples and 
pulmonary function tests as a baseline for our Raptor pilots, 
which has been very helpful for us to be able to determine once 
they have had an incident, is there something which is resident 
in their body, something which has a lingering effect? That was 
mostly aimed at the potential contamination, of which we found 
none. But I should step back a second and mention that everyone 
who flies in an Air Force aircraft who is a rated officer goes 
through a medical screening to be qualified for flight. And we 
have annual physical health assessments that we go through that 
recheck our pulmonary function, recheck our medical baselines 
from urinalysis to blood samples, et cetera. Very rigorous. In 
fact, every year, that's the day that pilots and aviators look 
least forward to, is that trip to see the doctor, hoping they 
still come out cleared to fly, as they do. We have a very 
rigorous process for evaluating the health of our aviators.
    What we have found is, with our pilots who operate in harsh 
environments, whether it be high-G environment or high-altitude 
environment, there are additional protocols that need to be in 
place to understand the effects. High-G environments F-15s, F-
16s, F-22s, we learned in the 1980s that if pilots were not 
properly trained, educated and equipped with anti-G protection, 
they literally could knock themselves unconscious, and 
tragically, we have lost many pilots to G loss of 
consciousness. Years ago, the trend had increased significantly 
with that training, education, and the equipment we gave them.
    What we are finding is that with the maturing that we have 
of the F-22 weapon system, we have been flying it operationally 
since 2003, but a small number of aircraft, so the sorties, it 
takes a while to get to numbers. What we are finding is this 
reaction to the interaction between the equipment, the oxygen 
delivery schedule, and we get this Raptor cough, what has been 
referred to as Raptor cough. We can talk about that a bit more, 
but those effects typically clear up within minutes, if not 
hours, after flight. We have had a small number of pilots who 
have had incidents that have had lingering effects that go out 
to 48 to 72 hours. But within 72 hours, with treatment by our 
aerospace medical professionals, those effects go away. All of 
our pilots, all of our ground crew who have had incidents, 
physiological incidents, have been returned to duty and fit for 
flight status.
    Mr. Reyes. And I have other questions, Mr. Chairman, but in 
deference to the members that are here I will wait another 
turn. But I did want to finish up by asking you, so your 
position, your effective positions are that we do have a way to 
go back and ensure that if something develops in the future for 
these pilots, there can be a way to evaluate and analyze how it 
might have been impacted by the F-22.
    General Lyon. If I may, to close that out, one of General 
Martin's recommendations was to establish a medical registry of 
all F-22 pilots and associated ground crew. We have done that 
with this baselining of their pulmonary tests and with their 
blood tests.
    What we have also learned from our friends at NASA, from 
their expertise, is that there are other tests that we can put 
in place, which will give us greater understanding and depth of 
knowledge about pulmonary function. That is a recommendation 
which has been given to me to incorporate into our findings as 
we close out our analysis. Importantly, we know who has flown 
the F-22. We know who has been exposed to this environment. We 
have a registry of those people from the time that we have been 
flying and will continue to track them through their Air Force 
career and, if necessary, beyond.
    We have a moral imperative, we understand that, that if 
something is discovered that would be tied to this aircraft or 
in servicing this aircraft, we have a moral imperative to take 
care of those Americans.
    Mr. Reyes. I thank the gentleman.
    Mr. Chairman, I yield back.
    Mr. Bartlett. Thank you. As per committee rules, members 
present at gavel fall are recognized in the order of seniority 
on the committee; those appearing after gavel fall, in the 
order their appearance at the committee.
    Ms. Hochul.
    Ms. Hochul. Thank you, Mr. Chairman.
    I would like to thank you for holding this important 
hearing, first of all. I share the same view as everyone in 
this room, that our pilots' safety has to be one of our highest 
priorities. I know today we are primarily speaking about the F-
22 issue, and I have a closely related question. As we continue 
to invest in the F-35 Joint Strike Fighter, a program I do 
strongly support, is the Air Force aware of any problems or 
potential problems that are looming similarly to what we are 
experiencing with the F-22 with the F-35 program, is this 
something we have been proactive about and anticipating?
    General Martin. Ma'am, I would say the charter that we had 
in the Air Force Scientific Advisory Board was to review other 
military aircraft equipped with OBOGS systems and determine if 
there were some lessons learned from those aircraft that we 
could apply in the F-22 and, additionally, were there some 
lessons from what we learned in the F-22 study that should 
apply or could apply to those aircraft. With respect to the F-
35, it is an OBOGS system. It is manufactured by the same 
manufacturer. It has a little different scheduling activity.
    We have shared all of our information with the F-35 program 
office, and I would say that their system was designed with a 
bit more redundancy and robustness. It has a backup oxygen 
system that is installed on the seat with a fairly large 
quantity of air available to the pilot should the OBOG system 
have a problem. And we know of no physiological incident that 
has occurred in any of the F-35 flight operations to date, 
through the flight test as well as some of the training 
activities that are occurring down at Eglin.
    So to your question with respect to the F-35, we did review 
the system. It does have some differences, but it looks as if 
those differences are refinements and improvements over what 
the F-22 had, and we have shared the information that we 
learned with the program office and, as well, with the Navy and 
Marine Corps, who will be operating that airplane as well.
    Ms. Hochul. That is all I have, Mr. Chairman.
    I yield back the balance of my time. Thank you.
    Mr. Bartlett. Mr. Runyan.
    Mr. Runyan. Thank you, Mr. Chairman.
    General Martin, I am sure there is a classified answer to 
this, but specifically speaking to operating environment of the 
F-22, what really differs between that and say the F-16, F-15, 
F/A-18? What really sets it apart?
    General Martin. Mr. Congressman, I will let General Lyon 
discuss perhaps some of the warfighting characteristics of the 
operational environment, but from a system design and human 
systems integration perspective, the F-22, unlike all other 
aircraft, can operate routinely and in a sustained manner above 
50,000 feet. Typically, the Air Force has required its air 
crews to use a full pressure suit when operating above 50,000 
feet, even though the cabin pressurization is adequate and 
safe. Should there be a rapid decompression at those altitudes, 
the effect on the blood and the effect on your ability to 
properly inspirate or breathe is very, very challenging without 
supplemental pressure to keep your lungs from exploding and to 
ensure that you are able to process the oxygen that is 
delivered.
    The F-22 does not have a full pressure suit, and it was 
designed to operate with a partial pressure suit, the upper 
pressure garment, a different anti-G suit and those sort of 
things. So that airplane operates in an environment different 
than what we had operated. For instance U-2s, SR-71s, those 
airplanes, all of those air crew members fly in a full pressure 
suit. The F-22 pilots do not, and therefore, it is important 
they not only understand where they are vulnerable and the 
limitations of the equipment but also the performance of the 
equipment as they operate in those areas. So our concern was 
making sure that not only did we have the right equipment and 
that it would perform well and provide the protection that it 
was intended to, but that the air crews would also know what 
the differences were and how to operate in that environment.
    So from a physiological perspective and from a design 
perspective, that is the area of focus for the Air Force 
Scientific Advisory Board.
    With respect to the combat capability and advantages, 
General Lyon I think can best address those for that 
environment.
    General Lyon. Congressman Runyan, I have over 3,000 hours 
flying the F-16, and I can count the amount of time that I have 
spent above 40,000 feet in less than 10 hours.
    When I look at the operating envelope that our F-22 pilots 
go into every day, every day, they go above 40,000 feet. They 
operate at higher altitudes routinely than we have in the F-16 
in the past and even than we did in the F-15. And they also 
operate in a very high-G environment.
    We have learned a lot over the last three decades about the 
impacts of operating in a high-G environment with our fourth-
generation fighter legacy aircraft, and we have integrated 
those efforts into the F-22. We still learn today, after half a 
century of flying the U-2 at extremely high altitudes, we are 
still learning how to care for those pilots and continuously 
enhance their safety because of their exposure to very high 
altitudes.
    As General Martin mentioned, we have a partial pressure 
suit in the F-22. It is a truly a hybrid aircraft that combines 
high altitude and high G. And some of the equipment that we 
found that we have is optimized for one of those environments 
but not integrated to help with the other environment. That is 
one of the key points that came out of our analysis over the 
last year, is that we need to continue to do research on the 
science, the physiology of both high altitude and high-G 
flying, and the end-to-end integration and testing of all of 
the components that have really one thing in mind. That is to 
ensure that the proper volume of oxygen with the proper 
concentration of oxygen gets to the pilot so he has full 
cognitive skills and can handle the immense tasks that they 
have in an environment that we have not flown routinely before.
    Mr. Runyan. And I asked that question just to say we 
understand that we can change the physiology of a machine, but 
we can't change the physiology of a human being. We can push 
the threshold with technology all day long. And I think this a 
prime example of, we have spent a lot of money on developing 
weapons and tactics that are outside the envelope, but we are 
not going to be able to change the person that flies it. And I 
think sometimes as we step back and look at things like this, 
we really have to be cautious. I have the honor to actually sit 
on the VA [Veterans' Affairs] Committee, and the list you speak 
to, I don't want to really have to visit that--you know what I 
mean--especially with the Raptor cough and all that kind of 
stuff.
    I would just say that technology is great, but at the end, 
it is about the people. It is the men and women that do this 
that we really have to look out for.
    With that, Mr. Chairman, I yield back.
    Mr. Bartlett. Thank you very much.
    Ms. Speier.
    Ms. Speier. Mr. Chairman and ranking member, I really 
appreciate you holding this hearing. I am deeply concerned 
about this issue. And I must say, I don't have the confidence 
that we have come up with the answer yet.
    Let me start by asking General Lyon, there was an article 
that appeared today in the Dallas Star-Telegram, and I don't 
know if you have seen it, but it suggests that the Air Force 
knew about this back in 2000, that it declined a fix in 2005 
that would have cost about $500,000 per aircraft. And that 
alone I think deserves your response. So if you would, please 
explain to the committee if you knew this back in 2000, if 
there was a fix back in 2005 that you declined to incorporate 
because of cost, which was at that time about $500,000.
    General Lyon. Congresswoman Speier, I will be happy to 
answer that question.
    During the engineering and manufacturing development phase 
of the F-22, we learned a lot. We had a lot of reports written 
about the status of different aircraft systems, subsystems, and 
how they interacted. And one of those reports was written in 
2000 about the environmental condition system. Changes have 
been made since then. Changes were made based on that report. 
In 2005, when the report came out and suggesting yet a small 
incremental change that you describe to this system, the 
knowledge that we had at the time was that--the term Raptor 
cough didn't even exist at that time. We didn't even know it. 
We had some discussions about ear blocks, but we have 
discussions about ear blocks in other aircraft that we fly as 
well. So the determination in 2005 was what we knew about some 
of these interactions, is that they were at a small level, not 
widely spread, and we were still a very small fleet size at 
that time.
    It is as we have grown to the final delivery of our 
aircraft and really expanded the people who fly and the numbers 
of hours that they fly that we have gained a bigger 
understanding of what is going on. And we continue to make 
changes to this oxygen delivery schedule based on what we learn 
along the way.
    Ms. Speier. So the suggestion in 2005 has now been 
incorporated or has not?
    General Lyon. That suggestion has not been incorporated 
specifically. It was a minor modification to the ECS 
[environmental control system] system and the scheduling 
performance. We are looking at broader changes than that and 
making broader changes that envelop that one that was suggested 
then.
    Ms. Speier. But wasn't that suggestion to give the pilot 
the opportunity to control the oxygen flow?
    General Lyon. The pilot does. The pilot has a switch 
setting in the aircraft, an automatic setting, which is a lower 
oxygen concentration, and a maximum setting, which is a higher 
oxygen concentration.
    We have learned a lot about oxygen concentration. There was 
a period of time when we thought we may not have been 
delivering enough oxygen concentration. But what we have 
learned over the last few years is that there are these cases 
where the increased oxygen concentration does give some 
dryness. It does give some ear block, and it does create this 
Raptor cough, which is a temporary situation.
    Ms. Speier. Thank you.
    There has been some discussion about the fact that it is 
not just the suit, that those on the ground are also 
experiencing this condition, these hypoxia-like symptoms. Are 
you confident that the epoxy that is used in adhering the skin 
to the plane is not a contributing factor to this?
    General Lyon. Congresswoman, I am confident. We have done 
over 2,400 tests on the aircraft.
    And if I may have the picture of the testing locations----
    Ms. Speier. Excuse me, I am running out of time. You have 
answered the question. Thank you.
    Let me move on to ask you whether or not the reports that 
you mentioned, one dating back to September, I guess, of last 
year, if those are going to be made public so that the findings 
and recommendations would be made available to the public?
    General Martin. The Air Force Scientific Advisory Board 
report has been completed. It has gone through its review, 
several tiers of reviews, and will be released today. And the 
findings and recommendations will be there.
    If I could, ma'am, I would make a comment that you will see 
in the report with respect to a better understanding of the 
interaction of this aircraft with the human operating the 
airplane, whether it be a maintenance technician or it be a 
pilot.
    In the 1990s, the United States Air Force, through its 
manpower reductions and its prioritization of effort, brought 
about by the downsizing of the military after Desert Storm, did 
not continue with the robust effort it had for decades before, 
its human systems integration, its aviation physiology.
    Ms. Speier. And you relied on contractors, correct?
    General Martin. Sorry?
    Ms. Speier. You relied on contractors as opposed to----
    General Martin. In many cases.
    Flight medicine and aviation physiology research and 
development atrophied significantly during those years. And at 
a time when the airplane was going into a different environment 
that we talked about earlier, the people that would normally 
have done the testing and the evaluation and all of the things 
that we do to learn about those new environments were no longer 
in the military, no longer in our civilian workforce.
    One of the recommendations is that the Air Force reenergize 
its efforts with respect to human systems integration so that 
we will better understand some of the interactions that we are 
now learning about and actually, with the help of the Navy and 
with NASA, know more about today than we did a year ago.
    Ms. Speier. Thank you.
    My time has expired.
    Mr. Bartlett. Thank you very much.
    I will ask a few questions, and then we will return, for 
those who are interested, to a second round of questions.
    I would just like to return for a moment to my opening 
statement to make sure that a couple of statements there 
weren't misunderstood. I read and concluded that either the 
supply or the quality of the oxygen is contributing to F-22 
pilots' hypoxia-like symptoms. I don't think those are the only 
two possible reasons for these symptoms. I was simply reporting 
what had been concluded. I didn't want this to be interpreted 
as a statement of fact.
    Next was the statement I made that the Air Combat Command 
had determined that the root cause of the F-22 pilot 
physiological issues is the supply of oxygen delivered to the 
pilots, not the quality of oxygen delivered to the pilots. This 
is what they concluded. I am not sure that is the correct 
resolution of the problem. I just wanted to make sure that 
people understood because I read those statements, I didn't 
read them as statements of fact, I read them as an account of 
what had been reported by the people who were investigating it.
    I hardly know where to begin. I spent a big part of my life 
in this area. And when I first came to work for the Navy as 
school physiologist in Pensacola, Florida, a great many years 
ago, they had just had an accident where the instructor and the 
student had penetrated a 10,000-foot floor and for several 
minutes were seen spiraling into the Pensacola sand. The 
commanding officer felt that there was a problem with the 
oxygen system. And since I was the physiologist, I was put on 
the Accident Investigation Board and we spent a very long time, 
as we appropriately do, looking at every aspect of this.
    Let me ask a few questions.
    The symptoms of hypocapnia, how early in your investigation 
were you cognizant of the fact that it was difficult to 
differentiate between hypocapnia and hypoxia? Hypocapnia is low 
carbon dioxide. If you sit and breathe deeply a number of 
breaths, if I sneeze three times, I have hypocapnia. I can feel 
the difference. I am dizzy. How far along were you in your 
investigation before you were cognizant of the fact that we 
ought to be looking at the symptoms of hypocapnia as well as 
the symptoms of hypoxia?
    General Lyon. Thank you for the question, Chairman 
Bartlett.
    We started to learn over the winter that there were a 
variety of symptoms that were emerging. And it was in April of 
this year where we had our restricted breathing working group 
that met, the combination of F-22 pilots and the professionals 
across the medical field, where we really got into substantial 
discussions about symptoms, as well as the research that had 
been done with Duke University by Dr. Mitchum and with the 
United States Navy, where we broadened our aperture and 
understood that these symptoms, like light-headedness, 
dizziness, fatigue, are actually ambiguous across things like 
toxic exposure, hypoxia, hypocapnia, hypercapnia, hypoglycemia, 
dehydration.
    But I would say for me as the task force lead, the ``aha'' 
moment came in April, when we got that full team of experts 
from different services, from NASA and from industry together. 
That is where it really started to emerge in our mind.
    Mr. Bartlett. How difficult is it to differentiate between 
the symptoms of hypoxia and hypocapnia?
    General Lyon. Chairman Bartlett, I tread on dangerous 
ground now engaging in a discussion with you with your level of 
knowledge about this. But what I have learned as the task force 
lead as I talk to professionals about this is that many of 
these symptoms are temporary. They emerge, and then they 
disappear. And it is hard to find any kind of DNA 
[Deoxyribonucleic Acid] trace that goes along with this. In 
fact, our protocols that have we put in place did not show any 
of these. So they are very temporary, and they come and go. So 
that has been one of the challenges.
    The other thing that they have told me is there is an 
individual variability factor here as well, that every human is 
a dependent variable if we think of this in terms of a test. 
And not only that, but from day to day, a human being is going 
to interact differently depending on how much sleep they had. 
Are they well rested? Are they hydrated? What are their blood 
sugar levels?
    So this understanding of the physiology and the science not 
only for, as Congressman Runyan was alluding to about the high 
altitudes and pushing the envelope, but just the basic 
physiology where we have let some of these skill set atrophy 
over the years as we downsized our Air Force during the post-
Cold War period, that we were relearning old lessons. But in 
April, that is where it all came back to me.
    Mr. Bartlett. Is it not true that, in large measure, the 
symptoms of hypoxia and the symptoms of hypocapnia are 
indistinguishable?
    General Lyon. Mr. Chairman, in fact, that is what I found. 
I have to put things in fairly simple terms, and I asked them 
to give me a chart listing all of these different cases, 
hypocapnia, hypercapnia, et cetera, and then listing what are 
the symptoms. It looks almost like a complete ladder of Xs from 
left to right all filled in. They are almost a one-for-one 
match of symptoms across all of these various symptoms that we 
talked about in these causes.
    Mr. Bartlett. We have a very interesting dynamic here. If 
you think that you are hypoxic, the normal response to that is 
to try and get more oxygen. That is what you need, so you 
breathe deeper and maybe faster. And you can do that, and you 
will not be aware of the fact that you are breathing deeper and 
faster. And when you do that, you now drive down CO2 [carbon 
dioxide], and you create the symptoms of the thing that you 
were trying to avoid, that is hypoxia, because as you drive 
down the carbon dioxide concentration in your body, you have 
essentially exactly the same symptoms that you would have if 
you had a low oxygen concentration in your body. So now you 
begin a vicious cycle. I feel worse. I need to breathe deeper. 
You don't say that to yourself, but that is the physiological 
response to that. So now you breathe deeper. And the deeper and 
faster you breathe, the worse you feel. So you are kind of on a 
vicious cycle here.
    What partial pressure of oxygen do you try to maintain in 
the breathing mixture? I am going to ask a question, too, about 
Raptor cough and try to make sure that people understand where 
that comes from, that this isn't something evil and it is just 
a natural consequence of doing what you do in flying these 
aircraft. This is what happens.
    General Lyon. Mr. Chairman, we mean well above the useful 
consciousness requirement for----
    Mr. Bartlett. We are roughly at sea level here. I think it 
is about 158, the partial pressure. And in our lungs it is 
diluted by CO2 and so forth, and it is down to about 100 
millimeters of mercury.
    General Lyon. Yes, sir.
    Mr. Bartlett. Do we try to maintain the concentration of 
oxygen significantly above 158 millimeters of mercury?
    General Lyon. Significantly above it, in fact. We are 
approaching 90 percent, 80-90 percent pure oxygen at the higher 
altitudes that we fly.
    Mr. Bartlett. What happens when you have a very high 
percentage of oxygen in your lungs is if that oxygen is picked 
up by the capillaries in the lungs, there is nothing then--the 
nitrogen is gone. You have eliminated that by increasing the 
oxygen percentage. Ordinarily here, we have about 80 percent 
nitrogen. It just stays in there and holds the alveoli open. 
What you end up with is a situation like if you take two pieces 
of wet paper and put them together, you have to tug at them to 
get them apart. That is the surface tension of water. That is 
what happens when you have a very high oxygen concentration. 
You increase the probability--and I noted you were recommending 
that they go to max oxygen--you now increase the probability of 
atelectasis because you are driving down the concentration of 
nitrogen, so you increase the incidence of atelectasis. And 
that is an irritation, and you cough to try to open those 
alveoli up, and it could take quite a while to open the alveoli 
up, which is why it may persist for awhile.
    You all have done an admirable job of pursuing this. All of 
these instances occurred at two of your eight bases, is that 
true?
    General Lyon. Mr. Chairman, we have six permanent operating 
bases.
    Mr. Bartlett. And at how many of those did this occur?
    General Lyon. And your eight is correct. We have two 
forward present bases.
    Mr. Bartlett. So eight total. And it occurred in only two.
    General Lyon. Only two.
    Mr. Bartlett. Which is another indication that what is 
happening here is not a problem with--and this is a very 
complex relationship between the pilot and his system. Pilots 
are taught early on that they can't really trust their senses. 
You have cockpit signals that tell you what is up and what is 
down, and you have learned to trust those rather than the seat 
of your pants, because you really can't trust that. And all of 
you have been, I gather, how many times do you go in that 
altitude chamber and they ask you to take off your mask? And 
you take off your mask, and you are doing something like 
writing something, and you think you are doing just fine. And 
then you put your mask back on, and you look at what you have 
done, and wow, how could I have done that? There is little 
perception that you are becoming hypoxic. And you think that 
you are doing just great, and the better you feel you are 
doing, the worse you are doing. So the pilots have learned that 
they can't really trust their senses. They have got to trust 
other things.
    I am really pleased that you put two things in this system 
that now pilots can look to. One is an oximeter on the ear now, 
I gather, that tells you what your oxygenation is in your 
blood. If that is up, you have got enough oxygen. No matter how 
you feel about it, you have got enough oxygen if that is up. I 
think you also put a sensor in that tells them what the percent 
oxygen is in their delivery system?
    General Lyon. Yes, Mr. Chairman.
    Mr. Bartlett. There needs to be a protocol that keeps that 
as near 158 as you can. If you run it much above that, you are 
going to increase the incidence of atelectasis. And this kind 
of breeds some perception that there is a problem with the 
airplane or a problem with the oxygen system or something if 
you have atelectasis. It is not a problem with either, it is 
just a fact that if you are breathing a high percentage of 
oxygen and pulling Gs, which is going to exacerbate the thing, 
that you are going to have more atelectasis.
    Well, I have asked enough questions for the moment.
    Let me turn to Mr. Reyes for his questions. And we'll come 
back.
    Mr. Reyes. Thank you, Mr. Chairman.
    Listening to the chairman, I was wondering, you know, we 
first deployed the F-22 in 2005, and it wasn't up until 2008 or 
so that these problems started to surface, so I am wondering 
what explanation is there for this time lag? Were the problems 
there all along and just not being reported, or did you change 
the operational, you know, operational capability--not 
capability but the operational environment of the F-22 that 
brought upon the pilots this problem?
    General Lyon. Thank you for that question, Congressman 
Reyes.
    After a few years of operational flying, we started to get 
a large number of aircraft, a larger population. We get into 
the individual variability of the pilots who were flying. And 
in 2008, we had several incidents.
    One of the things that was informative to me from Mr. 
Cragg's independent analysis was this thing known as the 
normalization of deviance, which was learned from their studies 
that they have done on some of their safety and engineering 
studies for things which have occurred with NASA in the past.
    There was an acceptance early on by the Raptor pilots who 
flew this aircraft that it is a littler harder to breathe than 
it is in other aircraft. And they were taught that it is a 
little harder to breathe, and they began to accept it. But over 
time, as the pool of pilots got larger and we flew more, we 
started to see some of this individual variability come into 
play. And then we had some incidents, and we really started 
focusing on it.
    What was also helpful for me as I worked through this 
analysis was looking at the Air Force's history in another 
aircraft, the F-16. The F-16 flew operationally for 4 years 
before it had the first G loss of consciousness [G-LOC]. Same 
capabilities in the aircraft; same G available, the same 
qualification and criteria to get into the aircraft. But we 
flew for 4 years. And I asked myself, why? I still don't have 
an answer as to why it took 4 years for G loss of consciousness 
to become an issue and then continue on for awhile. But it is 
not uncommon from what I have seen in some case studies to fly 
aircraft for a number of years, very selective pilots and 
aviators at the very beginning part, very controlled 
environments, but we start to broaden the aperture and bring 
more folks in, and we start to see more variability over time.
    Mr. Reyes. The other question that comes to my mind is we 
are dealing with the F-22 in this hearing, but are there 
lessons to be learned as we transition to the F-35? Does the F-
35--do we anticipate that it is going to have similar issues, 
or the fact that we are working our way through finding 
solutions for the F-22, is that going to be beneficial for the 
F-35?
    General Martin. Congressman Reyes, I would say this, that 
the F-35 oxygen system is more robust than the F-22 in terms of 
its design and redundancy. The formula that it uses for 
computing the percentage of oxygen is slightly different. And 
from the lessons we have learned with respect to connections, 
potential for leakage, and of course the emergency oxygen 
system, they have applied those lessons in the F-35.
    As General Lyon has indicated, that will not stop all 
potential hypoxia-like incidents or hypoxia incidents due to 
hyperventilation or other things that could occur. But in terms 
of the design, it seems as if the F-35 has gone to school on 
the F-22. And of course, both with what General Lyon's team has 
done and with what the AFSAB did, we have shared all of that 
information. In fact, during the early part of our study, 
NAVAIR systems people were fully integrated into our effort and 
shared with us the lessons they had learned in OBOGS in general 
and where they were with the F-35.
    So we are doing our best to make sure what we have learned 
here will apply to the training and to the design and operation 
of the F-35.
    Mr. Reyes. Thank you.
    And I have some other questions, but I will submit them for 
the record.
    Mr. Bartlett. Thank you.
    Ms. Speier.
    Ms. Speier. Thank you, Mr. Chairman.
    Mr. Cragg, I was particularly struck by the statement in 
your report that reads, the acceptance of these phenomena as, 
quote, normal could be seen as, quote, normalization of 
deviance, that the F-22 has no effective filtration of 
breathing air or cabin air and although no conclusive evidence 
has been found indicating the effect of irritant compounds, 
they could enter the cockpit and the pilot's breathing air 
supply.
    Could you comment a little more on those statements, 
please?
    Mr. Cragg. Sure. Thanks for the question.
    NASA is very familiar with the term ``normalization of 
deviance.'' It is when we get to a position where we accept the 
operation of some system or component that is not operating 
properly, and we start treating it as that is the way it 
normally is. And the best example from NASA's perspective was 
the foam coming off the external tank for the shuttle. It 
happened since the beginning, and we came to accept it as a 
normal part of doing business, but it wasn't. And we should 
have fixed it long before.
    So when we began examining the F-22, things like the Raptor 
cough, things like the pilots going home at night being 
physically exhausted, said to us, there is something that may 
fit into this category of normalization of deviance. So we 
wanted to point that out. It is a way that you can almost fall 
into that type of a mind set if everybody says it is normal, 
and especially with the F-22 being the top of the line Air 
Force fighter, when people say, do you want to fly this 
fighter? Yes, yes, of course, I do. There are some things that 
are different about this; it is harder to breathe, but the 
pilots just apparently didn't care. They wanted to jump in and 
begin flying it.
    So the normalization of deviance is a cultural thing that I 
think the Air Force needs to take a look at and help prevent 
from occurring in the future.
    Ms. Speier. And your reference to this filtration system 
and the fact that these toxic compounds can get into the oxygen 
system, could you comment on that?
    Mr. Cragg. We began our review by trying to double-check 
some of the things that we understood that the Air Force had 
already done. One of the things they looked at quite 
extensively was the contamination issue. So I had my people 
examine all of the evidence, the data, and we came up with a 
conclusion that we found no contaminants that were getting into 
either the breathing supply or the cockpit that would cause a 
toxic condition for the pilot.
    Having said that, during that examination, we found that 
the air coming into the cockpit and the breathing supply is not 
filtered. And so, it is not filtered, which would put the pilot 
in a position where he is breathing air like in any jet fighter 
environment. There are irritant compounds. There is potentially 
some exhaust gases that the individual may be breathing. We 
wanted to highlight the fact that the onboard oxygen generator 
is not a great filter. It is filtering a lot. Some of the cabin 
air that is coming into the cabin is being filtered by what is 
called coalescer socks. But we wanted just to point out that 
the air coming in is not completely pristine.
    Ms. Speier. Are you suggesting that it should be completely 
filtered?
    Mr. Cragg. No. No. Ultimately what we are suggesting is 
that some of these irritant compounds could potentially cause a 
pulmonary problem or a restriction of breathing. One of the 
members of my team is from the EPA, who has done testing with 
irritant compounds and has found that to be the case in some 
individuals. It is highly an individual response to that.
    Ms. Speier. Two more questions I want to try to get in in 
42 seconds here.
    The Air Force has said that none of the hypoxia incidents 
have resulted in long-term or lingering physiological effects. 
But a medical expert wrote in Flying Safety Magazine that a 
pilot who experienced these symptoms was restricted from flying 
for several days. Wives of pilots have also described what they 
believe to be long-term or lingering effects, and many of these 
pilots describe blackouts and memory loss when they experience 
symptoms. Some pilots also describe experiences of vertigo 
weeks later. To what degree do you think that we need to look 
at biomarkers as part of this evaluation?
    Mr. Cragg. I think that is a very good question. I had two 
NASA flight surgeons on my team, and they did some extensive 
review of what the Air Force has done. I would not like to 
speak for them. I wanted to make sure what we put in our report 
as far as the medical portion was exactly correct, so I ensured 
that that portion of our report was thoroughly peer-reviewed by 
other flight surgeons. So if you don't mind, ma'am, I will take 
that one for the record, and I will provide you an answer.
    [The information referred to can be found in the Appendix 
on page 105.]
    Ms. Speier. I appreciate that. One last question.
    Have any of the pilots declined to fly the F-22 because of 
what has transpired?
    General Lyon. We have one pilot across the entire F-22 
enterprise who is currently not on flying status based on his 
request.
    Ms. Speier. Thank you.
    Mr. Bartlett. Thank you very much.
    Mr. Reyes mentioned G-LOC; this is the unconsciousness you 
get when you are pulling Gs. And this is due to an apparent 
design defect in us. Essentially, every other part of our body 
has the ability to accumulate an oxygen debt, which is why you 
keep breathing, huffing and puffing, after you run hard. Our 
brain has zero ability to accumulate an oxygen debt. So the 
moment it doesn't have enough oxygen to operate, it just quits 
operating. And we try to avoid this, of course.
    When you are pulling Gs, the blood, by centrifugal force, 
it is taken down to your legs and abdomen. And we try to avoid 
this by anti-G suits, something that as soon as you start 
pulling Gs, they start squeezing on your abdomen and your legs 
to make sure that the blood can't pool there. But you can't 
always do enough of that, and sometimes the blood still may 
pool there enough that you get some transience. I have no idea 
why there is that design defect. You would think that ought to 
be built in. If anything needs to work all of the time, it is 
the brain, isn't it? But if it doesn't have enough oxygen, it 
just quits.
    Ms. Speier mentioned vertigo weeks later. I was just 
thinking, unless there is some pollutant in the oxygen, and I 
think you pretty much ruled that out with all of your testing, 
there is just nothing that can happen during flight, hypoxia or 
hyperventilation, that is going to--you might better look to 
what he did last night than look at the hypoxia or the 
hypocapnia that he experienced 6 weeks earlier.
    I have a series of questions that we would like to get 
answers to.
    Let me ask you, first of all, is there any evidence, other 
than circumstantial, that there was ever an hypoxic incident?
    General Lyon. Mr. Chairman, if I may lead and then if 
General Martin would like to add.
    One of the things that we found is that early on, the 
discussion centered on hypoxia, and then the discussion became 
hypoxia-like. But in the end, what our analysis said is these 
are physiological events, which get back to the things that we 
described a little earlier today that get into physiology. 
Physiological events is the umbrella, of which hypoxia is one 
of the parts of that. But most of these events are so 
ambiguous, and these multiple factors, that we didn't have the 
science early on when we had these incidents to really plumb to 
the depth required to determine hypoxia from exposure to 
compounds to hypoglycemia, et cetera.
    It is only through the protocols and the learning that came 
out of General Martin's efforts that we have been able to 
understand these incidents in more depth over the last year, 
that have allowed us to rule out things like contamination as a 
root cause for what was happening to our pilots. And we start 
to see that it is these breathing restrictions and breathing 
impedances, as you referred to, which can lead to hypercapnia 
or hypocapnia or similar type events for restricted breathing.
    But that is where I end the analysis with my conclusions, 
after I have taken all of the findings that have come in from 
the other bodies and looked at this in total. They are not 
hypoxia, per se. A small number of them are hypoxia.
    We have had some pilots who have had interruptions in their 
pilot supplies, and we have tracked that, and we have noted 
that. So we do know that if there was an interruption, a 
malfunction, that they will get less air and they will, indeed, 
become hypoxic. But most of what we have been studying, what we 
have been concerned about, are the instances where there was no 
explanation at the time, and they do not lead you to hypoxia.
    General Martin. During our review of the cases and after we 
initiated the return to fly phase, where we had the finger 
pulse oximeter, there were--we had data that seemed to 
correlate with the symptoms and the physiological presentation 
of what you would call hypoxia. For instance, a pilot cruising 
out through 15,000 feet began to sense his hypoxia symptoms, 
began to feel somewhat light-headed, looked at his pulse 
oximeter and saw that it was at 85 percent or 83 percent. As we 
went further into the data review over a period of months and 
gathered more data and became much more conversant with the 
strength and weaknesses of a tool such as that, we found that 
oftentimes what seemed to be a correlation turned out to be 
what the medical world refers to as artifact data or data that 
was not accurate. And we did not know at that time that perhaps 
the best indicator of whether the oximeter was working properly 
or not was the pulse. And if the pulse went away, then the 
oxygen dosage or the oxygenation number may not be accurate.
    So we thought we had some fairly representative samples of 
someone not getting the oxygen that they needed to perform 
without impairment and their symptoms. And it turned out that 
in almost every case, that data was inaccurate. Hence, the 
pulse oximeter that will go in the head because the extremity 
is the last place that the body is going to push the blood when 
necessary to preserve function of the brain and the core of the 
body. So we should get better data with this, but still there 
will be some artifact data just based on the technology used to 
measure.
    I have no doubt that some of the cases that we reviewed, 
that the pilot believed that he was suffering from hypoxia; but 
it may not have been hypoxia, it may have been the symptoms 
that were similar. And those are the symptoms that he or she 
felt in the physiological training unit. And when they went to 
high altitude, and one of the cases that you mentioned, not 
only do we do some exercises, but we are supposed to mark, if 
you will, perhaps a narrowing of the vision, perhaps a loss of 
color, perhaps a dizziness, perhaps a light-headedness, perhaps 
other symptoms. We are supposed to note that so if we felt that 
in the aircraft, then we would immediately go to 100 percent 
oxygen and recover the aircraft.
    I have no doubt that there were air crew members or pilots 
who experienced those same symptoms, but we can't prove that it 
was due to a lack of oxygen from the OBOGS system itself.
    Mr. Bartlett. Are we now acquainting our pilots with the 
similarity and the symptoms between hypocapnia and hypoxia?
    General Lyon. Mr. Chairman, indeed, we are. In fact, we 
have visited five of the six permanent location sites. The one 
location they are deployed currently, so we haven't been out to 
see them. But we have pushed them the information.
    Where we have shown them the results of the centrifuge and 
altitude chamber training, that was my next ``aha'' moment in 
about the May-June timeframe, where we, for the first time, put 
F-22 pilots, wearing their F-22 flying ensemble, into ground 
testing and altitude chambers and centrifuges, and we measured 
that the system was not performing the way we thought it had 
been performing over years.
    We have advanced the state of testing and our ability to 
understand what the oxygen delivery is. We have shown the 
results of that to the pilots. In fact, 2 of the first 12 
pilots who did centrifuge testing replicated their hypoxia 
symptoms on the ground in a centrifuge inside a closed 
building. That was an ``aha'' moment for me that really started 
to point toward one of the factors. As you rightly pointed out, 
Mr. Chairman, it is more than one factor. But one of the 
factors is this restriction in breathing or impedance in 
breathing, which can come--the restriction from the upper 
pressure garment, and the impedance from the C2A1 filter, which 
we have been flying with for a period of time to protect 
against the possibility of contaminants, and also the pressure 
drops that the Navy helped us with, in understanding it and 
NASA affirmed it. The pressure drops that occur inside the 
cockpit as the air flows through the oxygen hoses and the quick 
connects; we had measurable, objective data, and we have shown 
it to our pilots. And they are aware of that.
    We have not had an incident since the 8th of March this 
year, over 6 months ago. This is longest period without a 
physiological unexplained incident in years.
    Mr. Bartlett. Did you have an increased incidence of these 
events when you had the filter in?
    General Lyon. Mr. Chairman, we did. When we returned to fly 
September of last year, we put a number of measures in place to 
protect our pilots, to ensure their safety, to enhance their 
safety. And some of these things we put in place actually 
increased the incidence. One of the measures that we put in 
place was guidance from me to the entire F-22 fleet that said, 
at the first sign, the first symptom of anything, you are 
directed to terminate your mission and come home. We injected a 
sensitivity because safety was paramount in our mind. And they 
responded to that. And they did safely recover every aircraft 
each time that we had an incident.
    But I marked my guidance as the Air Combat Command Director 
of Operations with their safety as paramount, to come home and 
terminate it, that we have injected an increase in the incident 
rate during that timeframe.
    Mr. Bartlett. Yeah. I would have predicted an increase in 
the reported incidents if you put a noticeable resistance in 
the line because the response to that is, gee, it is hard to 
breathe; I am not getting enough oxygen; I need to breathe 
deeper. So when you do that, you create hypocapnia, and you 
create the symptoms of the things that you are trying to avoid, 
don't you?
    General Lyon. Mr. Chairman, you are exactly right.
    And to also dovetail off of what Mr. Cragg has said, when 
we put this canister on pilots and told them to fly with it to 
protect them in the event of contamination, what we failed to 
tell them was this known breathing impedance. We knew about the 
breathing impedance. What we didn't know was about the 
restriction in breathing that came with the upper pressure 
garment. And the combination of the restriction from the upper 
pressure garment plus this impedance we believe is what in this 
individual variability sent a number of our pilots beyond their 
normal physiological limits to where they saw these first 
symptoms.
    Mr. Bartlett. Let me quickly go through some questions that 
the staff wants to make sure we have on the record so there is 
no misunderstanding in the general public about the intensity 
of our effort to solve this problem. You don't need to give a 
full answer here. You may give a more complete answer for the 
record, if you wish.
    In your findings, you cite a number of failures in F-22 
modeling and simulation of the F-22 life support system. Do you 
believe engine-to-mask modeling and simulation, dynamic 
response testing across the full range of simulated 
environments, statistical analysis for analyzing and predicting 
system performance and risk, and OBOGS performance when 
presented with a full range of ECS air contaminants should be 
accomplished for the F-22 program?
    I guess a simple yes or no is okay.
    General Martin. Yes.
    Mr. Bartlett. What causes what has become known as the 
Raptor cough? How frequently is it experienced by the average 
F-22 pilot, and how serious an experience is it for the pilot? 
Does the Raptor cough have any long-term effect on the pilots? 
Do you think the record needs any more than what we have 
discussed?
    General Lyon. Individual variability, there is no standard 
number of events. Some individuals don't have it at all. Some 
have it more than others. And we have no indication of long-
term effect.
    Mr. Bartlett. You will reduce those incidents if you keep 
oxygen as low as is feasible, right. The blood is oxygenated 
not because you push a lot of oxygen pressure into it, because 
it has got hemoglobin, which carries blood. The amount of 
oxygen that is carried in the blood by solution in the blood is 
very small. So any time you get over 158 millimeters of mercury 
partial pressure, you are minisculely increasing the amount of 
oxygen available to the tissue, but you are considerably 
increasing the probability of atelectasis.
    Is there any linkage between hyperventilation and the 
Raptor cough? I was trying to think of--can you increase the 
Raptor cough atelectasis by hyperventilation?
    General Lyon. We have not made that linkage yet. Although 
what we have mentioned is one of the institutional things that 
we will continue to work on is further study of this man-
machine interface, not only for the F-22 but for other 
aircraft. Atelectasis and the Raptor cough, there is 
relationship between the two.
    Mr. Bartlett. Of course. That is why you have the cough.
    How thoroughly did your study group examine this issue, and 
does your report draw any conclusions or make any 
recommendations to address the Raptor cough issue? Is there any 
modification to the F-22 oxygen system that would minimize or 
eliminate the Raptor cough and its effect?
    I will answer my own question. If you keep the CO--or the 
oxygen level as close as you can to 158 millimeters of mercury, 
where your blood will be adequately oxygenated, you will reduce 
the incidences, I think.
    As you fill the lungs with more and more oxygen and less 
and less nitrogen is there to hold the alveoli open, you are 
going to increase the incidence of that; am I correct?
    General Lyon. Yes, Mr. Chairman.
    May I add one thing for the record, one of the reasons we 
are significantly above 158 is for protection against the 
possibility, however slight, but the possibility of rapid 
decompression at high altitudes. As you know, super-oxygenating 
the bloodstream will maximize our time of useful consciousness, 
should we have that take place.
    Mr. Bartlett. There is a press report this morning 
indicating that the Air Force medical experts linked the Raptor 
cough to the F-22's air supply system. I would hope so. The 
article indicates that the Air Force decided in 2005 not to 
make a fix to the F-22 oxygen system. Do you know if a 
modification to the F-22 air supply system was considered in 
2005 to address the Raptor cough issue and why the modification 
was not made?
    General Martin. Sir, let me give you a partial answer here. 
First of all, the bleed air satisfies many customers. It 
satisfies the cooling requirements for the flight control 
computer. It satisfies the communication navigation cooling 
system. It satisfies the fire control system. It provides 
pressurization to the cabin. And it also provides the 
pressurized air at a specific pressure and temperature to 
OBOGS, which then delivers breathing air to the pilot. It is 
controlled by a node, known as the air cycle machine, which 
meters the amount of air necessary to the customers, based on 
the pressurized air coming in as well as the temperature. If 
the temperature begins to creep up, which at high-altitude, 
low-power settings, it does, it then begins to shut down the 
delivery of the air to some of those customers down range, and 
the OBOGS is one of them. At that point, then, there is a 
restriction to the amount of air the pilot might get, to 
include zero, when the OBOGS has no pressure at the front.
    We knew that in the early testing, and there were 
modifications to the air cycle machine's algorithms that 
controlled the metering of the air, and that, again, was 
brought forward in the 2005 timeframe as a part of the 
discussion there.
    As a result of the SAB study, the program office has gone 
back into that algorithm and adjusted it again, because the 
number of ECS rollbacks or shutdowns was greater than predicted 
or expected, and they have tried to adjust that air cycle 
machine mechanism to reduce the number of shutdowns that would 
occur, therefore, shutting off the oxygen to the pilot.
    Further, as you know, from what General Lyon said, there 
will be a backup oxygen system placed on the aircraft so that 
if that happens, you will still get breathable air from the 
backup system that will be much larger than the basic emergency 
activation system we have today.
    Mr. Bartlett. In early designs of the F-22, didn't we have 
a backup system, and wasn't it taken out to reduce cost?
    General Martin. It was not a cost issue, sir. It is true 
that it was taken out. It did have an initial design of a 
backup oxygen in addition to the emergency oxygen system. A 
series of events occurred, but the catalyst for this particular 
decision was the term that every aircraft goes through, the war 
on weight.
    After the prototypes had flown, they then begin to go into 
their engineering, manufacturing, development phase. And at 
that point, you begin to find out where the strengths and 
weaknesses are. The aircraft always gain weight. When it gains 
weight, it may not be able to pass its key performance 
parameters of sustained G or acceleration or altitude or 
whatever. So, at that point, they had to get the weight down.
    The difficulty here was that as we went into acquisition 
reform, we created the IPT [Integrated Product Team] structure, 
and at that point, very tough decisions were made in terms of 
who had the authority to make certain decisions. That usually 
was generated as a result of a very conscientious review to 
determine where your safety-of-flight critical items were. And 
as the program evolved, the backup oxygen system, the OBOGS and 
the emergency oxygen system were not considered safety-of-
flight critical. They were safety significant, which meant that 
the decision to take the backup oxygen system off could be made 
at a lower level than the chief engineer of the F-22, and it 
was. And it was not known at that time by the senior leadership 
that that--the analysis that went into that trade study that 
allowed the backup oxygen system to come off.
    In retrospect, that was not an appropriate decision. But at 
that time, that is what the decision was. Now that decision was 
made also with the information that the environmental control 
system, ECS, IPT was going to put a shunt valve in that would 
always ensure there would be positive pressure to the OBOGS, 
and therefore, taking the backup system off would not be a 
problem, given that you had an emergency backup system should 
the OBOGS fail entirely.
    So what looks like what I would consider to be a flippant 
decision turned out to be steeped in data and very well thought 
out, but it was perhaps not viewed by the more experienced and 
senior engineer responsible for the F-22.
    Mr. Bartlett. If weight is that critical, what do we prune 
now so we can put it back in?
    General Martin. Sir, first of all, it was 15.4 pounds, as I 
recall. And they were looking for every pound they could find. 
The performance of the aircraft is so magnificent that 15 
pounds is not going to hurt this aircraft.
    Mr. Bartlett. Is there any explanation of why the reported 
hypoxia incidents have been concentrated at only two of the six 
operating bases?
    General Lyon. We asked the Air Force Safety Center, Mr. 
Chairman, to go to all of the F-22 bases and talk to the crews, 
the air crew and the ground crew, to help us understand some of 
the factors beyond what I would call hard science, beyond 
engineering science, and get into the human factors.
    One of the locations is Joint Base Elmendorf-Richardson, 
where tragically, in November 2010, Captain Jeff Haney lost his 
life. And there was a cluster of incidents that took place in 
May 2011, just before the standdown occurred. There is a 
residual effect within the community that occurs when you 
suffer through a tragedy. And as General Martin mentioned 
earlier today, there was a period of quite some time, nearly a 
year, uncertainty about what caused Captain Haney's crash and 
the loss of his life. So this built up and manifest inside the 
community, and there is residual effect that has come from 
that.
    At the other base, Joint Base Langley-Eustis, we found that 
there was a set of factors there where the C2A1 canister--and I 
can tell you from my discussions with all of the wings, the 
C2A1 canister had a different meaning at that installation than 
it did at the other five. And we saw several clusters take 
place. And the human factors engineers and scientists tell us 
that this is to be expected, that if there is a perception of a 
problem, and somebody credible within the organization has a 
problem, others will begin to experience the same thing. And 
that is what we had; credible aviators who had a perception 
that we had helped them believe, there is a problem with your 
life support system which could have been contamination, and at 
the first sign, saying, I have a problem, terminating the 
mission. Their credibility extended to other people at their 
installation. That is how we explain it.
    At the other installations, they never got to that point. 
But there were factors resident localized that had 
professionals make well-measured, good decisions to terminate 
missions because they had the perception that there was a 
problem.
    General Martin. One other comment, Mr. Chairman.
    When the Scientific Advisory Board recommended the return-
to-fly protocols and the steps to be taken, it knew or it 
believed that it would be important for us to continue the 
return-to-fly process until at least March of 2012, because 
that would give us a fairly representative sample across the 
fleet of the different seasons. It also turns out that at 
Elmendorf and at Langley, those two bases fly with the 
protective gear for winter operations, which means if you 
haven't readjusted your upper pressure garment and you now fly 
with more stuff, the restriction to the breathing could be 
greater. And the incidents may very well have also been related 
to the fact that we didn't have a proper standard for the upper 
pressure garment fitting, and then we didn't change the upper 
pressure garment fitting when we put on the rubberized and 
cold-weather gear.
    Mr. Bartlett. Thank you.
    General Lyon, I think you probably have articulated the 
major reason for this. A little anecdote may help put that in 
perspective.
    If you are provided a breathing mask and you are sat behind 
a screen and you are getting your air supply through a tube and 
you are told that, by and by, you will smell violets and you 
are supposed to indicate to the investigator when you smell 
violets, essentially everybody will smell violets. The 
investigator has not done one thing to the air supply.
    These are very subjective things, and it is kind of tough 
for us to recognize that we are not in full control of these 
things. But these are very subjective things. And if you think 
that there is going to be a problem with your oxygen supply 
system and you may become hypoxic, the least little thing will 
trigger this hyperventilation, unperceptible to the pilot, and 
he will then have exactly the symptoms of the thing that he 
dreaded, and that is hypoxia. It is a very interesting thing 
that has happened here, and I am sure that this was a learning 
experience for everybody who was involved in the investigation.
    Is there an explanation--why do you believe that the pilots 
have not previously complained until recently about the chest 
constriction caused by the upper pressure garment now 
determined to be a causal factor in the F-22 physiological 
problems?
    I am not sure, my statement seems to imply it was a causal 
factor.
    Do you think there is any causal factor other than the fact 
that the perception was, gee, my breathing is impeded a little 
and I guess I need to breathe more to get oxygen. And so they 
end up breathing more and get hypocapnia, which are exactly the 
symptoms of hypoxia? Is there another explanation?
    General Lyon. If I have the question correctly, and I am 
not sure I do, Mr. Chairman, how did they go for so long with 
this upper pressure garment filling prematurely, restricting 
their breathing and not knowing it, this is--what helped inform 
us was the normalization of deviance that Mr. Cragg has 
mentioned.
    When we put these F-22 pilots into the centrifuge with 
their gear on and they were accelerated to high G, we measured 
the fact that they were prematurely filling and restricting 
their breathing, and then we were able to measure, if we could 
have the chart that shows--as you can see on the chart in front 
you, Mr. Chairman, that without the upper pressure garment on, 
the tall blue spike shows how quickly they can inspire and get 
the required volume and that the red line shows that with the 
upper pressure garment on, they cannot get the depth that they 
need, and it takes longer to breathe. And as you already 
mentioned, Mr. Chairman, the brain just does this without the 
pilot knowing perceptibly that he is changing his breathing.
    This is what we have come to know, which the Navy helped us 
with, this understanding of the work of breathing. Breathing 
restrictions integrated into the pilot's flight ensemble, 
forced them to work harder to get the required volumes of air, 
which can then lead to fatigue symptoms over time.
    Mr. Bartlett. When I got my doctorate and its emphasis was 
in this subject 60 years ago, I never dreamed that I would be 
sitting here at a subcommittee hearing where this information 
would be relevant.
    Do all other fighter aircraft have a backup oxygen system?
    General Martin. Could you repeat that question, sir?
    Mr. Bartlett. Do all other fighter aircraft have a backup 
oxygen system?
    General Martin. Sir, they all have an emergency oxygen 
system, and they either have a backup oxygen system, or they 
have a plenum, which is like a reservoir that gives them 
additional air should the OBOGS system fail.
    Mr. Bartlett. Thank you very much for staying here through 
a very long subcommittee hearing. I hope that this puts at ease 
the minds of our pilots and their families. Thank you for doing 
a great job of investigating this, and thank you for your 
testimony today.
    [Whereupon, at 12:00 p.m., the subcommittee was adjourned.]
      
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                            A P P E N D I X

                           September 13, 2012

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              PREPARED STATEMENTS SUBMITTED FOR THE RECORD

                           September 13, 2012

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    [GRAPHIC(S) NOT AVAILABLE IN TIFF FORMAT]
      
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              WITNESS RESPONSES TO QUESTIONS ASKED DURING

                              THE HEARING

                           September 13, 2012

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             RESPONSE TO QUESTIONS SUBMITTED BY MS. SPEIER

    Mr. Cragg. The NESC Team report has described recommended medical 
courses of action for pilots who experience prolonged symptoms, based 
on what the NESC Team believes is the reason for these symptoms. Beyond 
that, the identification of precise biomarkers in hypoxic-ischemic 
injury in general, e.g. in victims of stroke, is still very much in the 
research phase, and not yet suitable for general diagnostic use, as in 
this case. [See page 26.]
?

      
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              QUESTIONS SUBMITTED BY MEMBERS POST HEARING

                           September 13, 2012

=======================================================================

      
                  QUESTIONS SUBMITTED BY MR. BARTLETT

    Mr. Bartlett. What have been the physiological consequences to the 
pilots in the reported hypoxia incidents? Have you categorized each of 
these incidents in terms of level of seriousness of the reported event? 
If so, what does the data show?
    General Lyon. There have been no long term physiologic consequences 
to pilots that have reported hypoxia incidents. Four pilots were 
treated in hyperbaric conditions due to the nature of their medical 
complaints. All pilots who reported hypoxia incidents have been 
medically returned to flying status. Level of seriousness is generally 
categorized by mishap/incident class. Classes of mishaps range from 
Class A (the most serious) to Class E (the least serious). Pilots who 
have reported hypoxia have categorically been Class E incidents.
    The data shows there have been no biomarkers found in the aircraft 
or pilots pointing to contamination in the breathing gas.
    Mr. Bartlett. What are the operational impacts to the current 
restrictions on F-22 operations? Are F-22s capable of operating 
throughout their full operational envelope if required to do so?
    General Lyon. F-22 aircraft are currently restricted to 44,000 feet 
during training missions with limited operational impacts. If required 
to do so, F-22 aircraft can operate throughout their full operational 
envelope.
    Mr. Bartlett. What is the status of actions on recommendations of 
General Martin's Aircraft Oxygen Generation Study Group?
    General Lyon. The Scientific Advisory Board (SAB) made a total of 
fourteen (14) recommendations; eight (8) short term and six (6) long 
term. The Air Force has completed seven (7) of the eight (8) short term 
recommendations. The remaining short term recommendation for Helmet 
Mounted Pulse Oxygen (HMPO) is on schedule to be completed in December 
of 2012.
    The six (6) remaining long term recommendations are on track for 
completion by the end of FY 2015.
    Mr. Bartlett. Is there a cost and time estimate to institute the 
planned actions to the F-22 life support system?
    General Lyon. Acquisition efforts are underway that include an 
Automatic Backup Oxygen System (A-BOS), Automatic Ground Collision and 
Avoidance System (AGCAS), Upper Pressure Garment Valve, Oxygen Hose 
Pass-Thru Panel, and Helmet Mounted Pulse Oximeter. These efforts are 
estimated to cost a total of $82.5M to develop and install on the 
entire fleet of F-22 aircraft.
    Mr. Bartlett. On what basis was the F-22 returned to flight in 
September 2011, since the Scientific Advisory Board and your Study 
Group had not completed their work?
    General Lyon. The Commander, Air Combat Command tasked ACC/A3 to 
implement the SAB study group's recommendations and to return the F-22 
fleet to flight operations in late August 2011. The SAB study group's 
recommendations were:
     1.  Incorporate additional aircraft life support inspections and 
modifications
     2.  Standardize OBOGS equipment to the ``-109'' configuration
     3.  Implement an OBOGS ground-based maintenance inspection 
procedure
     4.  Modify pilot life support equipment to incorporate the use of 
the C2A1 chemical warfare filter
     5.  Implement new post-incident medical and logistics protocols
     6.  Collect medical baseline blood samples for pilots and selected 
maintenance personnel who perform engine ground-run tests
     7.  Conduct baseline pulmonary function tests for pilots
     8.  Incorporate finger-mounted pulse oximeters into aircrew flight 
equipment
     9.  Eliminate the 25,000, mean sea level altitude flight 
restriction
    10.  Communicate the results of the investigations, testing and the 
advisory board's findings.
    In addition, Air Combat Command directed F-22 units to accomplish 
life support academics, emphasized oxygen delivery/life support 
emergency procedure training, and initiated guidance that directed 
pilots to terminate flight operations at the first sign/symptom of a 
physiological event. The F-22 community resumed flight operations on 21 
Sep 2011 after the Secretary of the Air Force approved the F-22A 
``Return to Fly'' Plan. The plan integrated the collective inputs of 
the operations, logistics, medical, safety and advisory board 
disciplines that had investigated the F-22 over the previous 3 years. 
The determination to resume flight operations balanced the current 
understanding of risk and the operational imperative to retain the 
readiness of the nation's Air Dominance fighter fleet. Pilot combat 
mission readiness skills are a perishable skill set. Some skills are 
retained through the use of flight simulators, other skills are not. 
Emerging insights from the 16 Nov 2010 fatal mishap--insights delayed 
by the inability to excavate the crash site until the summer thaw in 
Alaska, new inspection criteria for F-22 life support system components 
which ensure the veracity of the components, testing which began to 
eliminate ambiguities/uncertainties of previous physiological 
incidents; all coalesced to permit a thoughtful calculation to resume 
flight operations.
    Mr. Bartlett. What is the status of the Air Combat Command's Life 
Support Systems Task Force report, and when will it be released? Would 
you provide the committee a copy of the report when it is completed?
    General Lyon. The LSS TF final report is currently in draft with an 
estimated completion date of 31 Oct 2012. The report will be vetted 
through Headquarters Air Force and be available once released by Air 
Force leadership.
    Mr. Bartlett. We understand that the upper pressure garment was 
also used in F-15s and F-16s from the early 1990s through 2005. Why 
weren't vulnerabilities in the upper pressure garment determined while 
it was in use with the F-15 and F-16? Are there differences in the 
upper pressure garment system in the F-22 compared to the F-15 and F-
16?
    General Lyon. The Upper Pressure Garment (UPG) system being used in 
the F-22 is fully functional, compatible with, and meets all 
requirements for use with F-15 and F-16 aircraft. The physiological 
root cause investigation concluded the UPG was prematurely inflating 
due to the F-22's safety positive pressure breathing system. Neither 
the F-15 nor F-16 has safety positive pressure breathing systems.
    Mr. Bartlett. Why have ground maintenance personnel experienced 
symptoms if the issue is primarily linked to life support systems 
inside the cockpit?
    General Lyon. All ground incidents which occurred between 22 Sep 
2011 and 14 Dec 2011 were extensively investigated. All ground incident 
aircraft underwent contamination inspection prior to return to flight 
in September 2011 as well as more extensive post incident testing. This 
testing contributed to some of the overall F-22 contamination analysis. 
None of the ground incident aircraft cockpit testing revealed anything 
approaching a remarkable health guidance value. None of the maintainer 
blood, breath or urine samples indicated anything remarkable. Fluid 
found in the cockpit of one incident aircraft was evaluated and 
determined to be water with nothing remarkable.
    During one incident, investigators suspected tailwind engine 
exhaust may reach the cockpit and possibly effect maintainers. However, 
post incident testing and continued testing on two F-22 aircraft has 
indicated nothing remarkable. Engine run qualified ground maintenance 
personnel did receive updated engine run procedures to increase 
awareness, and to allow them to shutdown and reposition aircraft or 
equipment in the event of excessive exhaust. Engine run maintenance 
personnel also carried air sampling canisters in the cockpit for 
several months to capture any air samples from any potential incidents.
    However, no incidents occurred during this timeframe which was 
subsequent to the last ground incident in Dec 2011. Maintainers across 
the F-22 fleet perform in excess of a hundred engine runs every month--
runs which do not include aircraft movement. The Air Force has trained 
and implemented procedures for maintainers to quickly and safely shut 
down a running aircraft in the event of any future incidents. 
Additionally, appropriate aircraft and medical protocols are in place 
to respond to any future incidents.
    Mr. Bartlett. Please describe the Air Force's efforts to 
definitively determine that stealth coatings, along with other 
contaminants, did not cause any of these incidents. Could stealth 
coatings that were heated either on the ground or in flight cause 
contamination in that manner?
    General Lyon. LO Coatings and its breakdown products, along with 
other potential contaminants were incorporated into an extensive 
Molecular Characterization Matrix effort that thoroughly characterized, 
analyzed and documented over 900 compounds that could be present in 
aircraft environments. After several years of exhaustive testing both 
on the ground and in flight, no detected compounds levels have ever 
exceeded safe limits, or even been close to safe limit thresholds.
    All potential compound sources in an F-22 were evaluated including 
fuel, hydraulic fluid, engine oil, radar coolant, ambient air, engine 
exhaust, aircraft cleaning products, sealants, and coatings. Source 
breakdown analysis was performed and potential source information was 
incorporated into the Molecular Characterization Matrix for each 
compound. Of the 900 compounds characterized, only approximately 450 
were ever detected on an F-22 aircraft.
    Compound detection methods used on F-22 aircraft were capable of 
detecting a full spectrum of compounds. Detection media included 
Thermal Desorption Tubes, SUMMA canisters, multi-RAEs, sock and swab 
analyses, Greywolf, PUF/XAD, Silica Gel, C2A1 filters and GRIMM/CPC 
particulate counter, among others. The detection methods used were 
capable of detecting a wide range of particulate matter, volatile and 
semi-volatile compounds, and standard gases. Over 2,000 total samples 
were taken using these devices, at different times, both on ground and 
in-flight. Chemists and toxicologists performed countless reviews of 
sampling techniques and methods and culminated their effort with a 
detection methods expert forum to ensure that the full spectrum of 
aircraft compounds would have been adequately detected by the methods 
used in testing and sample analysis.
    Post incident protocols were established as part of Return to 
Flight in September 2011 and completed after each incident flight and 
maintainer incident. The protocol directed sampling at various areas of 
the aircraft including cockpit and breathing line air. All incident 
aircraft had levels of detected compounds well below established safe 
limits.
    Safe limits were developed with a team of over 20 experienced 
toxicologists, doctors, and scientists from contractor, NASA, 
University, and USAF personnel. These limits were derived from 
established OSHA guidelines, existing available research, Permissible 
Exposure Limits (PELs), Short Term Exposure Limits (STELs), and other 
established guidelines for each compound. In addition to aircraft 
sampling, blood, urine, and exhaled breath samples were taken from all 
incident pilots and maintainers and reviewed by an independent medical 
team of 5 physiologists, toxicologists, and aerospace physicians from 
the contractor, USAF, University and NASA. No abnormalities were noted 
in any tests. If a pilot was exposed to reactive LO coating materials, 
pilot blood tests should have revealed abnormal levels of heavy metals 
present. None were detected.
    A thorough review of maintenance activities on incident aircraft 
was completed and there were no maintenance trends prior to incident 
flights. Incidents have not been linked to any specific maintenance 
activities, including initial LO application and/or coating repair.
    In addition, compounds unique to LO coatings are unlikely to still 
be present in their reactive state during flight operations, since 
precautions are taken when coatings are applied. The aircraft is 
isolated to prevent exposure to personnel and Technical Order Documents 
(TOD) dictate that the aircraft are not returned to flight line 
operations until coatings are cured and paints are dry. Therefore, it 
is highly unlikely that these coatings were present during ground or 
in-flight operations.
    Based on the exhaustive research conducted to date, the team 
believes that contamination is not the root cause of the F-22 
Physiological Incidents.
    Mr. Bartlett. How do F-22 g-forces cause what is referred to as 
``Raptor cough''? Why does the Air Force feel it is not related to the 
physiological incidents pilots are experiencing?
    General Lyon. The term ``Raptor Cough'' is commonly known as 
acceleration atelectasis. Acceleration atelectasis results from pilots 
breathing high concentrations of oxygen (above 60%) while wearing anti-
G trousers, and exposure to G-forces. Atelectasis refers to the closure 
of alveoli in the terminal bronchioles as oxygen is absorbed into the 
blood stream, leaving no component of normal breathing gas (i.e. 
nitrogen) to keep them open. The normal physiologic response to re-open 
the alveoli is to cough. The F-22 consistently delivers higher 
concentrations of oxygen compared to legacy fighters increasing 
susceptibility to developing atelectasis.
    The Air Force feels that atelectasis may be a contributor to the 
``Raptor Cough'' issue. The Air Force will continue to explore further 
potential causes through long term breathing air analysis and human 
systems integration efforts.
    Mr. Bartlett. What is the Air Force's level of confidence in 
whether or not the life support equipment issues are contributing to 
all of the physiological incidents with pilots and ground personnel in 
the F-22 community?
    General Lyon. The Root Cause Corrective Action (RCCA) team 
exhaustively investigated 414 separate fault tree branches to arrive at 
high confidence in the overall F-22 Life Support System equipment. The 
Upper Pressure Garment (UPG) valve is the only remaining vulnerability, 
and is on-track for resolution in December 2012.
    The F-22 LSS Task Force is very confident that we know what was 
causing physiological incidents. No single cause was identified; rather 
multiple factors defined during the root cause corrective action (RCCA) 
combine to produce symptoms. These factors include human factors, 
breathing system impedance, high O2 concentration, and Upper Pressure 
Garment restriction caused by a fill/dump valve that was not 
specifically designed for the F-22. Pilot/Maintainer variability 
contributes to symptom manifestation differences. We are also confident 
that factors other than the life support system or the aircraft caused 
the ground incidents.
    Mr. Bartlett. You have previously indicated that of the 11 reported 
``cause unknown'' hypoxia events since return to fly in September 2011, 
less than half of those events are still unresolved. How many of the 
reported incidents can you contribute to an insufficient supply of 
oxygen?
    General Lyon. Of the 11 reported ``cause unknown'' events since 
September 2011, all 11 have been resolved under the general cause of 
restricted breathing. This determination was made through the 
independent investigations made at each mishap wing, supported by 
personnel and resources at the major command level along with experts 
from the F-22 program office, Lockheed-Martin, and outside support from 
experts at the U.S. Navy and NASA.
 
        Date                                              Event Description20-Oct-11            Hypoxia symptoms on departure--restricted breathing
20-Oct-11            Post flight personnel recognized cognitive degradation from pilot--restricted breathing
31 Oct 11            Pilot experienced symptoms in flight--restricted breathing
15 Nov 11            Pilot experienced symptoms during high-G sortie--restricted breathing
14 Dec 11            Hypoxia symptoms in flight--restricted breathing
14 Feb 12            Confusion during/post flight--restricted breathing
17 Feb 12            Confusion during intercept trng--restricted breathing
17 Feb 12            Confusion during RTB--restricted breathing
23 Feb 12            Hypoxia symptoms during RTB--restricted breathing
1 Mar 12             Pilot confusion, Spatial D in IMC--restricted breathing
8 Mar 12             Hypoxia symptoms during night RTB--restricted breathing
    Mr. Bartlett. You have previously indicated that of the 11 reported 
``cause unknown'' hypoxia events since return to fly in September 2011, 
less than half of those events are still unresolved. Could you provide 
an update on the status of each of those events including which are 
resolved with a cause for each, and which are still unresolved and 
actions being taken to address those unresolved cases?
    General Lyon. All of the events since September 2011 have been 
resolved under the general cause of restricted breathing. This 
determination was made through the independent investigations made at 
each mishap wing, supported by personnel and resources at the major 
command level along with experts from the F-22 program office, 
Lockheed-Martin, and outside support from experts at the U.S. Navy and 
NASA.
 
        Date                                              Event Description20-Oct-11            Hypoxia symptoms on departure--restricted breathing
20-Oct-11            Post flight personnel recognized cognitive degradation from pilot--restricted breathing
31 Oct 11            Pilot experienced symptoms in flight--restricted breathing
15 Nov 11            Pilot experienced symptoms during high-G sortie--restricted breathing
14 Dec 11            Hypoxia symptoms in flight--restricted breathing
14 Feb 12            Confusion during/post flight--restricted breathing
17 Feb 12            Confusion during intercept trng--restricted breathing
17 Feb 12            Confusion during RTB--restricted breathing
23 Feb 12            Hypoxia symptoms during RTB--restricted breathing
1 Mar 12             Pilot confusion, Spatial D in IMC--restricted breathing
8 Mar 12             Hypoxia symptoms during night RTB--restricted breathing
    Mr. Bartlett. Were you provided access to any Air Force data or 
facilities your team deemed necessary to carry out your review of the 
Air Force's investigative process and root-cause analysis?
    Mr. Cragg. Yes, the USAF provided the NASA Engineering and Safety 
Center (NESC) F-22 Life Support System (LSS) Independent Analysis Team 
with access to all of the data and facilities needed.
    Mr. Bartlett. You mentioned in your written statement that you 
believed insufficient human-systems integration testing was 
accomplished before operational deployment of the F-22. What additional 
testing do you believe should have been accomplished?
    Mr. Cragg. One of the NESC's Team's recommendations was to ensure 
appropriate human system integration testing is performed before 
operational use of any new system or implementation of a change to an 
existing system. Life support components (e.g., the On-Board Oxygen 
Generator (OBOGs)) were all individually qualified and put into the 
system by a system integrator. The original F-22 qualification testing 
did not utilize the same Aircrew Flight Equipment (AFE) that is in use 
today. Many of the complex interactions between the end-to-end system 
and the pilots were just recently identified during the human 
centrifuge and altitude chamber testing.
    Mr. Bartlett. You noted in your written statement that in any jet 
fighter environment, irritant compounds like combustion exhaust gases, 
fuels, lubricants, and organic cleaning solvents can be present. Are 
you confident in the Air Force's analysis that irritant compounds could 
not be in the pilot's breathing air supply thereby causing hypoxia-like 
effects?
    Mr. Cragg. As stated, irritant compounds are present in any jet 
fighter environment, including the F-22. The NESC Team found no 
evidence of a contaminant producing a toxic exposure for the pilots 
flying the F-22. The NESC Team recommended that the USAF ``Consider a 
fundamental reassessment of requirements and assumptions for LSS in 
high performance aircraft.'' Such an assessment would provide a better 
understanding of the physiological effects of irritant compounds in 
high performance aircraft.
    Mr. Bartlett. What is the status of the NASA Engineering and Safety 
Center report, and when will it be released? Would you provide the 
committee a copy of the report when it is completed?
    Mr. Cragg. The USAF requested NASA's review of hypoxia-like issues 
with the F-22. On August 31, 2012, the NESC presented the USAF with the 
final report. Accordingly, the USAF is responsible for any further use 
or release of the report, and NASA has agreed to defer to the USAF on 
such requests.
    Mr. Bartlett. Are you confident that, in addition to removing the 
filter, improvements to the pilots' gear, such as the upper pressure 
garment, will fix the F-22's physiological problems?
    Mr. Cragg. The NESC Team believes that there are multiple issues 
affecting the pilot's physiology in the F-22. Addressing each of these 
issues will ensure that the hypoxia-like symptoms will become less 
likely. Removing the C2A1 filter that exacerbated the problems and 
fixing the Upper Pressure Garment are major improvements.
                                 ______
                                 
                   QUESTIONS SUBMITTED BY MR. RUNYAN
    Mr. Runyan. General Martin, in your testimony before the 
subcommittee, you stated that the decision to pull the backup oxygen 
system was made by a lower level team, not the chief engineer 
supervising the program. It was also stated that this was done to save 
weight and that assumptions were made that the main oxygen system would 
be improved to accommodate, however there was no coordination between 
the two teams and the main oxygen system did not receive any 
improvements to make up for the lack of a backup system. General Lyon 
and General Martin, please provide the full name(s) of each of the 
person(s) who made the decisions, what his/her/their current position 
is for each person who signed off, and what actions have been taken to 
hold these people accountable for their decisions in light of 
subsequent events. Thank you.
    General Martin. The decision to remove the F-22 Back-Up Oxygen 
capability was made at an F-22 Cockpit Requirements/Design Review 
Update on Wednesday, 15 Jan 92. ``B/U Oxygen--OBOGS'' was one of the 7 
trade studies reviewed during this requirements/design review. The 
minutes of this review clearly show concurrence with the trade study 
recommendation to ``delete dedicated standby oxygen supply requirement 
for OBOGS backup'' and ``use emergency oxygen for emergencies.'' There 
were 25 government members at this meeting. After a thorough review of 
the Air Force's historical F-22 records, we are unable to determine 
who, specifically, made the decision to remove the F-22 Back-Up Oxygen 
capability from the F-22 design. Similarly, we have identified no 
instances in which adverse action was taken against an Air Force 
employee as a result of his/her making such a decision.
    Mr. Runyan. Do you think that you have found the actual cause of 
the problem? What is the source of the ``Raptor cough''?
    General Martin. The source of the ``Raptor Cough'' is a combination 
of breathing high concentrations of oxygen, wear of anti-G trousers, 
and exposure to G forces. Raptor Cough is commonly known as 
acceleration atelectasis. Acceleration atelectasis results from pilots 
breathing high concentrations of oxygen (above 60%) while wearing anti-
G trousers, and exposure to G-forces. Atelectasis refers to the closure 
of alveoli in the terminal bronchioles as oxygen is absorbed into the 
blood stream, leaving no component of normal breathing gas (i.e. 
nitrogen) to keep them open. The normal physiologic response to re-open 
the alveoli is to cough. The F-22 consistently delivers higher 
concentrations of oxygen compared to legacy fighters increasing 
susceptibility to developing atelectasis.
    The Air Force feels that atelectasis may be a contributor to the 
``Raptor Cough'' issue. The Air Force will continue to explore further 
potential causes through long term breathing air analysis and human 
systems integration efforts.
    Mr. Runyan. Can the F-22 be retrofitted with a current oxygen 
system that we can have full confidence in?
    General Martin. The Air Force has full confidence in the current F-
22 On-Board Oxygen Generation System based on our extensive testing 
during the F-22 Life Support System root cause investigation.
    Mr. Runyan. General Martin, in your testimony before the 
subcommittee, you stated that the decision to pull the backup oxygen 
system was made by a lower level team, not the chief engineer 
supervising the program. It was also stated that this was done to save 
weight and that assumptions were made that the main oxygen system would 
be improved to accommodate, however there was no coordination between 
the two teams and the main oxygen system did not receive any 
improvements to make up for the lack of a backup system. General Lyon 
and General Martin, please provide the full name(s) of each of the 
person(s) who made the decisions, what his/her/their current position 
is for each person who signed off, and what actions have been taken to 
hold these people accountable for their decisions in light of 
subsequent events. Thank you.
    General Lyon. The decision to remove the F-22 Back-Up Oxygen 
capability was made at an F-22 Cockpit Requirements/Design Review 
Update on Wednesday, 15 Jan 92. ``B/U Oxygen--OBOGS'' was one of the 7 
trade studies reviewed during this requirements/design review. The 
minutes of this review clearly show concurrence with the trade study 
recommendation to ``delete dedicated standby oxygen supply requirement 
for OBOGS backup'' and ``use emergency oxygen for emergencies.'' There 
were 25 government members at this meeting. After a thorough review of 
the Air Force's historical F-22 records, we are unable to determine 
who, specifically, made the decision to remove the F-22 Back-Up Oxygen 
capability from the F-22 design. Similarly, we have identified no 
instances in which adverse action was taken against an Air Force 
employee as a result of his/her making such a decision.
    Mr. Runyan. Do you think that you have found the actual cause of 
the problem? What is the source of the ``Raptor cough''?
    General Lyon. The source of the ``Raptor Cough'' is a combination 
of breathing high concentrations of oxygen, wear of anti-G trousers, 
and exposure to G forces. Raptor Cough is commonly known as 
acceleration atelectasis. Acceleration atelectasis results from pilots 
breathing high concentrations of oxygen (above 60%) while wearing anti-
G trousers, and exposure to G-forces. Atelectasis refers to the closure 
of alveoli in the terminal bronchioles as oxygen is absorbed into the 
blood stream, leaving no component of normal breathing gas (i.e. 
nitrogen) to keep them open. The normal physiologic response to re-open 
the alveoli is to cough. The F-22 consistently delivers higher 
concentrations of oxygen compared to legacy fighters increasing 
susceptibility to developing atelectasis.
    The Air Force feels that atelectasis may be a contributor to the 
``Raptor Cough'' issue. The Air Force will continue to explore further 
potential causes through long term breathing air analysis and human 
systems integration efforts.
    Mr. Runyan. Can the F-22 be retrofitted with a current oxygen 
system that we can have full confidence in?
    General Lyon. The Air Force has full confidence in the current F-22 
On-Board Oxygen Generation System based on our extensive testing during 
the F-22 Life Support System root cause investigation.
    Mr. Runyan. Why is the ACC commander, General Hostage, not at the 
hearing? Does he not consider this situation a serious problem? As a 
member of both the House Armed Services and House Veterans Affairs 
Committees, I would also like to have heard testimony directly from him 
since this all ultimately falls under his responsibility as ACC 
Commander.
    General Lyon. General Mike Hostage is happy to address any 
additional concerns of the committee anytime he is called. On this 
occasion, Maj Gen Lyon was called by the committee to appear on 13 
September. As General Hostage's most senior staff officer and ACC's 
Director of Air and Space Operations, Maj Gen Lyon was appointed to 
lead the F-22 Life Support System (LSS) Task Force by the Secretary of 
the Air Force. This represented a major commitment of headquarters 
efforts. As LSS lead, Maj Gen Lyon was empowered to speak for the Air 
Force on the subject. He holds the seniority and position to speak 
authoritatively, and has the most comprehensive knowledge of the 
subject.
    General Hostage made F-22 pilot safety and operational capability a 
top priority for ACC through his orders, commitment of time and 
resources, and personal actions. Due to the seriousness of his 
concerns, General Hostage closely monitored the situation and made all 
the key decisions on this issue, such as approving the F-22s return to 
flying operations.
    Lastly, General Hostage took the step of becoming an F-22 pilot 
himself in order to gain firsthand knowledge of operating the aircraft, 
and to demonstrate his belief that the overall risk levels our pilots 
take while operating the F-22 is comparable with that associated with 
most other high performance aircraft, given the numerous corrective 
actions and operating guidelines now in place.
    Mr. Runyan. Do you think that you have found the actual cause of 
the problem? What is the source of the ``Raptor cough''?
    Mr. Cragg. The NESC Team believes that there are multiple issues 
affecting the pilot's physiology in the F-22. Addressing each of these 
issues will ensure that the hypoxia-like symptoms will become less 
likely. Removing the C2A1 filter that exacerbated the problems, 
adjusting the oxygen schedule down from ``Max,'' and fixing the Upper 
Pressure Garment are major improvements. The NESC Team believes that 
the ``Raptor Cough'' is likely caused by a combination of atelectasis, 
high oxygen concentrations, and other physiological factors.
    Mr. Runyan. Can the F-22 be retrofitted with a current oxygen 
system that we can have full confidence in?
    Mr. Cragg. The NESC Team believes that the current Honeywell On 
Board Oxygen Generator (OBOGs) is operating properly and as designed.
                                 ______
                                 
                   QUESTIONS SUBMITTED BY MS. SPEIER
    Ms. Speier. General Martin, you mentioned that the F-22 program's 
ability to detect these issues was degraded by the Air Force's 
increased reliance upon contractors. Do you know approximately what the 
ratio of government to contractor employees working on human systems 
integration was in the Air Force then, and what that ratio is now?
    General Martin. Thank you for the opportunity to clarify and expand 
on this issue. Although the Panel did not specifically review the ratio 
of government to contractor manning with regard to the human systems 
integration competencies, based on what the Panel members heard from 
contractor and USAF personnel with deep experience in the human system 
fields, the degradation in the ``detection of issues'' resulted from an 
overall reduction in government and contractor expertise in the field 
of human systems expertise within both the Air Force and the contractor 
community that occurred over a more than 20-year period beginning in 
1990.
    In this context, ``human systems'' encompasses human factors 
engineering, human systems integration, aerospace physiology (research 
and operational), and aerospace life support systems design/
development/testing/evaluation. A significant reduction in manning and 
funding, for both the government and contractor workforces dealing with 
Human System Integration, Aviation Physiology, or Flight Medicine 
(especially in altitude physiology, altitude protection, oxygen 
generation systems, and occupational toxicology) occurred during the 
years of the F-22's engineering, development and manufacturing (EMD) 
phase and during its operational fielding. In Appendix E of the SAB's 
Aircraft Oxygen Generation Study Final Report, a discussion of that 
reduction is more fully described. Specifically, during the 1996-2000 
period, Air Force Research Laboratory Human Effectiveness manpower (and 
the associated research funding) for continuing human effectiveness 
activities (including research and development of human systems 
integration, aviation physiology and flight medicine) was reduced by 44 
percent. The Air Force indicated at the time it was willing to accept a 
higher risk in the application of human-centered technologies; and in 
particular, aircraft cockpit design technologies, environmental 
protection research, and life support systems were considered 
sufficiently mature that future research and development could 
therefore be accomplished by industry.
    While the Air Force can and does rely on contractor expertise in 
many fields that type of contractor-provided ``expert force in being'' 
exists only when funded over a period of time so that expertise can be 
developed and maintained at a high level. The contractor community does 
maintain certain (limited) ``core'' sets of technical expertise from 
within its own resources for vital future business reasons. However, 
the aerospace physiology and life support areas, especially as 
applicable to high performance military aircraft, represent a long term 
high commitment/low return area and in general, contractors have not 
maintained that technical expertise without significant continuing 
support (i.e., government funding/contracts for basic and applied 
research). Although in a slightly different context, the USAF faces 
much the same problem and, as mentioned above, has reduced its research 
capabilities and expertise accordingly.
    Ms. Speier. One of the findings of the Scientific Advisory Board 
was that the Air Force had insufficient capabilities and expertise for 
human systems integration. How does the Air Force plan to improve this 
expertise?
    General Lyon. The Air Force recognized the need to reestablish the 
Human Systems Integration competency in 2007 when we created the Air 
Force Human Systems Integration Office (AFHSIO) as a direct reporting 
agency to the Vice Chief of Staff of the Air Force. A recognition of 
the relationship of this office to weapon systems development resulted 
in a realignment of this office to the Undersecretary of the Air Force 
for Acquisition in 2009. The AFHSIO serves as a central policy source 
and tracking center for human systems integration (HSI) in acquisition 
programs. The team is currently assessing the number of HSI 
practitioners required, developing a concept of operations (CONOPS) for 
supporting program offices, determining training and certification 
required, and establishing a reporting mechanism.
    Ms. Speier. General Lyon, the Safety Advisory Board recommended 
more clearly defining inherently governmental roles and 
responsibilities in the Air Force's acquisition processes and core 
competencies. How has the Air Force responded to this recommendation?
    General Lyon. The Office of the Deputy Assistant Secretary of the 
Air Force for Acquisition Integration (SAF/AQX) reviewed, updated, 
published guidance, and reported the results of their review to the 
Military Deputy, Office of the Secretary of the Air Force for 
Acquisition (SAF/AQ).
    Ms. Speier. Mr. Cragg, you said that your team's conclusions ``do 
not represent an exhaustive review of all F-22 documentation.'' What 
other documentation would an exhaustive review include?
    Mr. Cragg. The NESC Team would define ``exhaustive review'' to 
include review and evaluation of every single document and data source. 
An exhaustive review requires a significant amount of time and 
personnel. Based on the NESC Team's experience, the key documents 
necessary to understand the situation and to provide significant 
recommendations to the USAF were identified and reviewed.
    Ms. Speier. Mr. Cragg, what issues should the Air Force explore in 
any studies of the long term impacts of the F-22's physiological 
strain?
    Mr. Cragg. The NESC Team believes that in some cases there could be 
a hypoxic-ischemic injury to certain areas of the brain that accounts 
for the prolonged neurocognitive symptoms experienced by some pilots. 
Based on early discussions with USAF medical representatives, a more 
objective assessment of neurocognitive function (e.g. computerized 
testing), as well as certain imaging studies (e.g. MRI of the brain), 
may be warranted in pilots who experience prolonged hypoxia-like 
symptoms associated with F-22 flight. Pulmonary function and diffusion 
testing for all F-22 pilots should also be considered. Further 
specifics of such testing (e.g. type and frequency) would best be 
addressed by technical experts in this field.
                                 ______
                                 
                  QUESTIONS SUBMITTED BY MR. LOEBSACK
    Mr. Loebsack. What solutions has the Air Force reviewed to solve 
the hypoxia problems experienced by pilots? Specifically, what oxygen 
delivery system changes have been reviewed and were all available 
solutions reviewed?
    General Martin. The Air Force has reviewed various proposed 
solutions to the hypoxia problems experienced by pilots. Included are 
modifications to the breathing assembly such as the Raptor 2 
modification which introduced a chemical warfare canister in-line with 
air supply to the pilot. This was done to mitigate potential 
contamination before this theory was disproven. Further, the Air Force 
required pilots to wear pulse oximeters for the first time in history 
in an attempt to quantify arterial blood saturation.
    We have reviewed numerous other potential solutions including 
modifications to the aircraft and have concluded that adding an 
automatic back-up oxygen system would meet requirements to have 
immediate 100% oxygen available in the event of a rapid decompression 
at extreme high altitudes. Other potential solutions investigated 
included changing the oxygen source from the current on board system to 
liquid and/or gaseous oxygen systems.
    Mr. Loebsack. Since the Air Force pointed to the recent travel of 
F-22s to Japan as an indicator that the hypoxia problem has been 
solved, does that mean that there were no risk mitigation restrictions 
placed on the F-22s during the transit?
    General Martin. The Air Force has kept all risk mitigation measures 
in place during F-22 long duration flights. Since resuming long-
distance F-22 missions in February 2012, the Air Force has completed 
over 100 long-distance F-22 sorties, totaling over 650 hours. There 
have been zero conditions or physiological incidents during any of 
these sorties that would require the use of these risk mitigation 
measures. After thorough investigation there is no data to suggest that 
these risk mitigations are any more necessary on long-duration F-22 
movements than with any other USAF fighter aircraft.
    Mr. Loebsack. What solutions has the Air Force reviewed to solve 
the hypoxia problems experienced by pilots? Specifically, what oxygen 
delivery system changes have been reviewed and were all available 
solutions reviewed?
    General Lyon. The Air Force has reviewed various proposed solutions 
to the hypoxia problems experienced by pilots. Included are 
modifications to the breathing assembly such as the Raptor 2 
modification which introduced a chemical warfare canister in-line with 
air supply to the pilot. This was done to mitigate potential 
contamination before this theory was disproven. Further, the Air Force 
required pilots to wear pulse oximeters for the first time in history 
in an attempt to quantify arterial blood saturation.
    Mr. Loebsack. Since the Air Force pointed to the recent travel of 
F-22s to Japan as an indicator that the hypoxia problem has been 
solved, does that mean that there were no risk mitigation restrictions 
placed on the F-22s during the transit?
    General Lyon. The Air Force has kept all risk mitigation measures 
in place during F-22 long duration flights. Since resuming long-
distance F-22 missions in February 2012, the Air Force has completed 
over 100 long-distance F-22 sorties, totaling over 650 hours. There 
have been zero conditions or physiological incidents during any of 
these sorties that would require the use of these risk mitigation 
measures. After thorough investigation there is no data to suggest that 
these risk mitigations are any more necessary on long-duration F-22 
movements than with any other USAF fighter aircraft.