[Federal Register Volume 77, Number 59 (Tuesday, March 27, 2012)]
[Rules and Regulations]
[Pages 18099-18102]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2012-7280]
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Rules and Regulations
Federal Register
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Federal Register / Vol. 77, No. 59 / Tuesday, March 27, 2012 / Rules
and Regulations
[[Page 18099]]
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 25
[Docket No. FAA-2012-0344; Special Conditions No. 25-461-SC]
Special Conditions: Dassault Aviation, Model Falcon 7X Airplanes;
Seats With Inflatable Shoulder Straps
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final special conditions; request for comments.
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SUMMARY: These special conditions are issued for the Dassault Aviation
Model Falcon 7X airplane. This airplane will have a novel or unusual
design feature associated with seats with inflatable shoulder straps.
The applicable airworthiness regulations do not contain adequate or
appropriate safety standards for this design feature. These special
conditions contain the additional safety standards that the
Administrator considers necessary to establish a level of safety
equivalent to that established by the existing airworthiness standards.
DATES: The effective date of these special conditions is March 19,
2012. We must receive your comments by May 11, 2012.
ADDRESSES: Send comments identified by docket number FAA-2012-0344
using any of the following methods:
Federal eRegulations Portal: Go to http://www.regulations.gov and follow the online instructions for sending your
comments electronically.
Mail: Send comments to Docket Operations, M-30, U.S.
Department of Transportation (DOT), 1200 New Jersey Avenue SE., Room
W12-140, West Building Ground Floor, Washington, DC, 20590-0001.
Hand Delivery or Courier: Take comments to Docket
Operations in Room W12-140 of the West Building Ground Floor at 1200
New Jersey Avenue SE., Washington, DC, between 8 a.m. and 5 p.m.,
Monday through Friday, except federal holidays.
Fax: Fax comments to Docket Operations at 202-493-2251.
Privacy: The FAA will post all comments it receives, without
change, to http://www.regulations.gov/, including any personal
information the commenter provides. Using the search function of the
docket web site, anyone can find and read the electronic form of all
comments received into any FAA docket, including the name of the
individual sending the comment (or signing the comment for an
association, business, labor union, etc.). DOT's complete Privacy Act
Statement can be found in the Federal Register published on April 11,
2000 (65 FR 19477-19478), as well as at http://DocketsInfo.dot.gov.
Docket: Background documents or comments received may be read at
http://www.regulations.gov at any time. Follow the online instructions
for accessing the docket or go to the Docket Operations in Room W12-140
of the West Building Ground Floor at 1200 New Jersey Avenue SE.,
Washington, DC, between 9 a.m. and 5 p.m., Monday through Friday,
except federal holidays.
FOR FURTHER INFORMATION CONTACT: Dan Jacquet, FAA, Airframe and Cabin
Safety Branch, ANM-115, Transport Airplane Directorate, Aircraft
Certification Service, 1601 Lind Avenue SW., Renton, Washington 98057-
3356; telephone 425-227-2676; facsimile 425-227-1149.
SUPPLEMENTARY INFORMATION: The FAA has determined that notice of, and
opportunity for prior public comment on, these special conditions are
impracticable because these procedures would significantly delay
issuance of the design approval and thus delivery of the affected
aircraft. In addition, the substance of these special conditions has
been subject to the public comment process in several prior instances
with no substantive comments received. The FAA therefore finds that
good cause exists for making these special conditions effective upon
issuance.
Comments Invited
We invite interested people to take part in this rulemaking by
sending written comments, data, or views. The most helpful comments
reference a specific portion of the special conditions, explain the
reason for any recommended change, and include supporting data.
We will consider all comments we receive by the closing date for
comments. We may change these special conditions based on the comments
we receive.
Background
On March 15, 2011, Dassault Aviation applied for a change to Type
Certificate No. A59NM to install an inflatable restraint system on side
facing divans in Dassault Aviation Model Falcon 7X airplanes (hereafter
referred to as ``Falcon 7X''). The Falcon 7X is a 19-passenger,
transport category airplane powered by three aft-mounted Pratt &
Whitney PW307A high-bypass-ratio turbofan engines. Maximum takeoff
weight is 69,000 pounds, and maximum certified altitude is 51,000 feet
with a range of 5,700 nautical miles.
The inflatable restraint system is designed to limit occupant
forward excursion in the event of an accident. This will reduce the
potential for head injury, thereby reducing the Head Injury Criteria
(HIC) measurement. The inflatable restraint system behaves similarly to
an automotive inflatable airbag, but in this case the airbag is
integrated into the shoulder strap and inflates away from the seated
occupant. While inflatable airbags are now standard in the automotive
industry, the use of an inflatable shoulder strap is novel for
commercial aviation.
Title 14, Code of Federal Regulations (14 CFR) 25.785 requires that
occupants be protected from head injury by either the elimination of
any injurious object within the striking radius of the head, or by
padding. Traditionally, this has required a setback of 35 inches from
any bulkhead or other rigid interior feature or, where not practical,
specified types of padding. The relative effectiveness of these means
of injury protection was not quantified. With the adoption of Amendment
25-64 to part 25, specifically Sec. 25.562, a new standard that
quantifies required head injury protection was created.
Section 25.562 specifies that each seat type design approved for
crew or passenger occupancy during takeoff and landing must
successfully complete dynamic tests or be shown to be compliant by
rational analysis based on dynamic tests of a similar type seat. In
particular, the regulations require that
[[Page 18100]]
persons not suffer serious head injury under the conditions specified
in the tests, and that protection must be provided or the seat be
designed so that the head impact does not exceed a HIC of 1000 units.
While the test conditions described for HIC are detailed and specific,
it is the intent of the requirement that an adequate level of head
injury protection be provided for passengers in a severe crash.
Because Sec. Sec. 25.562 and 25.785 and associated guidance do not
adequately address seats with inflatable shoulder straps, the FAA
recognizes that appropriate pass/fail criteria need to be developed
that do fully address the safety concerns specific to occupants of
these seats.
Type Certification Basis
Under the provisions of 14 CFR 21.101, Dassault Aviation must show
that the Falcon 7X, as changed, continues to meet the applicable
provisions of the regulations incorporated by reference in Type
Certificate No. A59NM or the applicable regulations in effect on the
date of application for the change. The regulations incorporated by
reference in the type certificate are commonly referred to as the
``original type certification basis.'' The regulations incorporated by
reference in Type Certificate No. A59NM are as follows: 14 CFR part 25,
effective February 1, 1965, including Amendments 25-1 through 25-111 in
entirety, and in accordance with 14 CFR part 11, Special Conditions No.
25-346-SC: High Intensity Radiated Fields (HIRF) Protection.
The U.S. type certification basis for the Falcon 7X is established
in accordance with 14 CFR 21.29 and 21.17 and the type certification
application date. The U.S. type certification basis is listed in Type
Certification Data Sheet No. A59NM.
If the Administrator finds that the applicable airworthiness
regulations (i.e., 14 CFR part 25) do not contain adequate or
appropriate safety standards for the Falcon 7X because of a novel or
unusual design feature, special conditions are prescribed under the
provisions of Sec. 21.16.
Special conditions are initially applicable to the model for which
they are issued. Should the type certificate for that model be amended
later to include any other model that incorporates the same novel or
unusual design feature, the special conditions would also apply to the
other model.
In addition to the applicable airworthiness regulations and special
conditions, the Falcon 7X must comply with the fuel vent and exhaust
emission requirements of 14 CFR part 34 and the noise certification
requirements of 14 CFR part 36.
The FAA issues special conditions, as defined in 14 CFR 11.19, in
accordance with Sec. 11.38, and they become part of the type
certification basis under Sec. 21.101.
Novel or Unusual Design Features
The Falcon 7X will incorporate the following novel or unusual
design feature: Dassault Aviation is proposing to install inflatable
shoulder straps on side facing divans to reduce the potential for head
injury in the event of an accident. The inflatable shoulder strap works
similarly to an automotive airbag, except that the airbag is integrated
with the shoulder strap of the restraint system.
Part 25 states the performance criteria for head injury protection
in objective terms. However, none of these criteria are adequate to
address the specific issues raised concerning seats with inflatable
shoulder straps. The FAA has therefore determined that, in addition to
the requirements of part 25, special conditions are needed to address
requirements particular to installation of seats with inflatable
shoulder straps.
Accordingly, in addition to the passenger injury criteria specified
in Sec. 25.785, these special conditions are adopted for Falcon 7X
airplanes equipped with inflatable shoulder straps. Other conditions
may be developed, as needed, based on further FAA review and
discussions with the manufacturer and civil aviation authorities.
Discussion
From the standpoint of a passenger safety system, the inflatable
shoulder strap is unique in that it is both an active and entirely
autonomous device. While the automotive industry has good experience
with airbags, the conditions of use and reliance on the inflatable
shoulder strap as the sole means of injury protection are quite
different. In automobile installations, the airbag is a supplemental
system and works in conjunction with an upper torso restraint. In
addition, the crash event is more definable and of typically shorter
duration, which can simplify the activation logic. The airplane
operating environment is also quite different from automobiles and
includes the potential for greater wear and tear and unanticipated
abuse conditions (due to galley loading, passenger baggage, etc.).
Airplanes also operate where exposure to high intensity electromagnetic
fields could affect the activation system.
The inflatable shoulder strap has two potential advantages over
other means of head impact protection. First, it can provide
significantly greater protection than would be expected with energy-
absorbing pads; and second, it can provide essentially equivalent
protection for occupants of all stature. These are significant
advantages from a safety standpoint, since such devices will likely
provide a level of safety that exceeds the minimum standards of the
federal aviation regulations. Conversely, inflatable shoulder straps in
general are active systems and must be relied upon to activate properly
when needed, as opposed to an energy-absorbing pad or upper torso
restraint that is passive and always available. Therefore, the
potential advantages must be balanced against this and other potential
disadvantages in order to develop standards for this design feature.
The FAA has considered the installation of inflatable shoulder
straps to have two primary safety concerns: First, that they perform
properly under foreseeable operating conditions, and second, that they
do not perform in a manner or at such times as would constitute a
hazard to the airplane or occupants. This latter point has the
potential to be the more rigorous of the requirements, owing to the
active nature of the system.
The inflatable shoulder strap will rely on electronic sensors for
signaling and a stored gas canister for inflation. These same devices
could be susceptible to inadvertent activation, causing deployment in a
potentially unsafe manner. The consequences of inadvertent deployment,
as well as failure to deploy, must be considered in establishing the
reliability of the system. Dassault Aviation must substantiate that the
effects of an inadvertent deployment in flight either would not cause
injuries to occupants or that such deployment(s) meet the requirement
of Sec. 25.1309(b). The effect of an inadvertent deployment on a
passenger or crewmember that might be positioned close to the
inflatable shoulder strap should also be considered. The person could
be either standing or sitting. A minimum reliability level will have to
be established for this case, depending upon the consequences, even if
the effect on the airplane is negligible.
The potential for an inadvertent deployment could be increased as a
result of conditions in service. The installation must take into
account wear and tear so that the likelihood of an inadvertent
deployment is not increased to an unacceptable level. In this context,
an appropriate inspection interval and self-test capability are
considered
[[Page 18101]]
necessary. Other outside influences are lightning and high intensity
radiated fields (HIRF). Existing HIRF special conditions for the
Dassault Aviation Model Falcon 7X airplanes, Special Conditions No. 25-
346-SC, are applicable. Finally, the inflatable shoulder strap
installation should be protected from the effects of fire, so that an
additional hazard is not created by, for example, a rupture of the
pyrotechnic squib.
In order to be an effective safety system, the inflatable shoulder
strap must function properly and must not introduce any additional
hazards to occupants as a result of its functioning. There are several
areas where the inflatable shoulder strap differs from traditional
occupant protection systems, and requires special conditions to ensure
adequate performance.
Because the inflatable shoulder strap is essentially a single use
device, there is the potential that it could deploy under crash
conditions that are not sufficiently severe as to require head injury
protection from the inflatable shoulder strap. Since an actual crash is
frequently composed of a series of impacts before the airplane comes to
rest, this could render the inflatable shoulder strap useless if a
larger impact follows the initial impact. This situation does not exist
with energy absorbing pads or upper torso restraints, which tend to
provide continuous protection regardless of severity or number of
impacts in a crash event. Therefore, the inflatable shoulder strap
installation should provide protection, when it is required, by not
expending its protection during a less severe impact. Also, it is
possible to have several large impact events during the course of a
crash, but there is no requirement for the inflatable shoulder strap to
provide protection for multiple impacts.
Since each occupant's restraint system provides protection for that
occupant only, the installation must address seats that are unoccupied.
It will be necessary to show that the required protection is provided
for each occupant regardless of the number of occupied seats, and
considering that unoccupied seats may have shoulder straps that are
active.
The inflatable shoulder straps should be effective for a wide range
of occupants. The FAA has historically considered the range from the
fifth percentile female to the ninety-fifth percentile male as the
range of occupants that must be taken into account. In this case, the
FAA is proposing consideration of a broader range of occupants, due to
the nature of the shoulder straps installation and its close proximity
to the occupant. In a similar vein, these persons could have assumed
the brace position, for those accidents where an impact is anticipated.
Test data indicate that occupants in the brace position do not require
supplemental protection, and so it would not be necessary to show that
the inflatable shoulder straps will enhance the brace position.
However, the inflatable shoulder straps must not introduce a hazard in
the case of deploying into the seated, braced occupant.
Another area of concern is the use of seats, so equipped, by
children whether lap-held, in approved child safety seats, or occupying
the seat directly. Similarly, if the seat is occupied by a pregnant
woman, the installation should address such usage, either by
demonstrating that it will function properly, or by adding appropriate
limitation on usage.
Since the inflatable shoulder strap will be electrically powered,
there is the possibility that the system could fail due to a separation
in the fuselage. Since this system is intended as crash/post-crash
protection means, failure to deploy due to fuselage separation is not
acceptable. As with emergency lighting, the system should function
properly if such a separation occurs at any point in the fuselage.
Since the inflatable shoulder strap is likely to have a large
volume displacement, the inflated bag could potentially impede egress
of passengers. Since the bag deflates to absorb energy, it is likely
that an inflatable shoulder strap would be deflated at the time that
persons would be trying to leave their seats. Nonetheless, it is
considered appropriate to specify a time interval after which the
inflatable shoulder strap may not impede rapid egress. Ten seconds has
been chosen as a reasonable time, since this corresponds to the maximum
time allowed for an exit to be openable (Sec. 25.809). In actuality,
it is unlikely that an exit would be prepared by a flight attendant
this quickly in an accident severe enough to warrant deployment of the
inflatable shoulder strap, and the inflatable shoulder strap is
expected to deflate much quicker than ten seconds.
Part I of appendix F to part 25 specifies the flammability
requirements for interior materials and components. There is no
reference to inflatable restraint systems in appendix F, because such
devices did not exist at the time the flammability requirements were
written. The existing requirements are based on both material types, as
well as use, and have been specified in light of the state-of-the-art
of materials available to perform a given function. In the absence of a
specific reference, the default requirement would be for the type of
material used to construct the inflatable restraint, which is a fabric
in this case. However, in writing special conditions, the FAA must also
consider the use of the material, and whether the default requirement
is appropriate. In this case, the specialized function of the
inflatable shoulder strap means that highly specialized materials are
needed. The standard normally applied to fabrics is a 12-second
vertical ignition test. However, materials that meet this standard do
not perform adequately as inflatable shoulder straps. Since the safety
benefit of the inflatable shoulder strap is significant, the
flammability standard appropriate for these devices should not screen
out suitable materials, thereby effectively eliminating use of
inflatable shoulder straps. The FAA will need to establish a balance
between the safety benefit of the inflatable shoulder strap and its
flammability performance. At this time, the 2.5-inch per minute
horizontal test is considered to provide that balance. As the
technology in materials progresses (which is expected), the FAA may
change this standard in subsequent special conditions to account for
improved materials.
The following special conditions can be characterized as addressing
either the safety performance of the system or the system's integrity
against inadvertent activation. Because a crash requiring use of the
inflatable shoulder strap is a relatively rare event, and because the
consequences of an inadvertent activation are potentially quite severe,
these latter requirements are probably the more rigorous from a design
standpoint.
Finally, it should be noted that these special conditions are
applicable to the inflatable shoulder straps as installed. These
special conditions are not an installation approval. Therefore, while
these special conditions relate to each such system installed, the
overall installation approval is a separate finding and must consider
the combined effects of all such systems installed.
Applicability
As discussed above, these special conditions are applicable to the
Dassault Aviation Model Falcon 7X. Should Dassault Aviation apply at a
later date for a change to the type certificate to include another
model incorporating the same novel or unusual design feature, the
special conditions would apply to that model as well.
[[Page 18102]]
Conclusion
This action affects only certain novel or unusual design features
on one model of airplanes. It is not a rule of general applicability.
The substance of these special conditions has been subjected to the
notice and comment period in several prior instances and has been
derived without substantive change from those previously issued. It is
unlikely that prior public comment would result in a significant change
from the substance contained herein. Therefore, because a delay would
significantly affect the certification of the airplane, which is
imminent, the FAA has determined that prior public notice and comment
are unnecessary and impracticable, and good cause exists for adopting
these special conditions upon issuance. The FAA is requesting comments
to allow interested persons to submit views that may not have been
submitted in response to the prior opportunities for comment described
above.
List of Subjects in 14 CFR Part 25
Aircraft, Aviation safety, Reporting and recordkeeping
requirements.
The authority citation for these special conditions is as follows:
Authority: 49 U.S.C. 106(g), 40113, 44701, 44702, 44704.
The Special Conditions
Accordingly, pursuant to the authority delegated to me by the
Administrator, the following special conditions are issued as part of
the type certification basis for Dassault Aviation Model Falcon 7X
airplanes.
1. Seats with Inflatable Shoulder Straps. It must be shown that the
airbag system in the shoulder strap will deploy and provide protection
under crash conditions where it is necessary to prevent serious injury.
The means of protection must take into consideration a range of stature
from a two-year-old child to a ninety-fifth percentile male. The airbag
system in the shoulder strap must provide a consistent approach to
energy absorption throughout that range of occupants. In addition, the
following situations must be considered:
a. The seat occupant is holding an infant.
b. The seat occupant is a child in a child restraint device.
c. The seat occupant is a child not using a child restraint device.
d. The seat occupant is a pregnant woman.
2. The airbag system in the shoulder strap must provide adequate
protection for each occupant regardless of the number of occupants of
the seat assembly, considering that unoccupied seats may have an active
airbag system in the shoulder strap.
3. The design must prevent the airbag system in the shoulder strap
from being either incorrectly buckled or incorrectly installed, such
that the airbag system in the shoulder strap would not properly deploy.
Alternatively, it must be shown that such deployment is not hazardous
to the occupant and will provide the required injury protection.
4. It must be shown that the airbag system in the shoulder strap is
not susceptible to inadvertent deployment as a result of wear and tear
or inertial loads resulting from in-flight or ground maneuvers
(including gusts and hard landings) and other operating and
environmental conditions (vibrations, moisture, etc.) likely to be
experienced in service.
5. Deployment of the airbag system in the shoulder strap must not
introduce injury mechanisms to the seated occupant or result in
injuries that could impede rapid egress. This assessment should include
an occupant whose belt is loosely fastened.
6. It must be shown that inadvertent deployment of the airbag
system in the shoulder strap, during the most critical part of the
flight, will either meet the requirement of Sec. 25.1309(b) or not
cause a hazard to the airplane or its occupants.
7. It must be shown that the airbag system in the shoulder strap
will not impede rapid egress of occupants 10 seconds after airbag
deployment.
8. The airbag system must be protected from lightning and HIRF. The
threats to the airplane specified in existing regulations regarding
lightning, Sec. 25.1316, and special conditions regarding HIRF,
Special Condition No. 25-346-SC, are incorporated by reference for the
purpose of measuring lightning and HIRF protection. For the purposes of
complying with HIRF requirements, the airbag system in the shoulder
strap is considered a ``critical system'' if its deployment could have
a hazardous effect on the airplane; otherwise, it is considered an
``essential'' system.
9. The airbag system in the shoulder strap must function properly
after loss of normal aircraft electrical power and after a transverse
separation of the fuselage at the most critical location. A separation
at the location of the airbag system in the shoulder strap does not
have to be considered.
10. It must be shown that the airbag system in the shoulder strap
will not release hazardous quantities of gas or particulate matter into
the cabin.
11. The airbag system in the shoulder strap installation must be
protected from the effects of fire such that no hazard to occupants
will result.
12. There must be a means for a crewmember to verify the integrity
of the airbag system in the shoulder strap activation system prior to
each flight, or it must be demonstrated to reliably operate between
inspection intervals. The FAA considers the loss of the airbag-system
deployment function alone (i.e., independent of the conditional event
that requires the airbag system deployment) to be a major failure
condition.
13. With regard to Sec. 25.853, the inflatable material may not
have an average burn rate of greater than 2.5 inches/minute when tested
using the horizontal flammability test defined in part 25, appendix F,
part I, paragraph (b)(5).
14. The airbag system in the shoulder strap, once deployed, must
not adversely affect the emergency-lighting system (i.e., block floor
proximity lights to the extent that the lights no longer meet their
intended function).
Issued in Renton, Washington, on March 19, 2012.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 2012-7280 Filed 3-26-12; 8:45 am]
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