[Federal Register Volume 77, Number 57 (Friday, March 23, 2012)]
[Rules and Regulations]
[Pages 16910-16914]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2012-6957]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 25
[Docket No. FAA-2012-0311; Special Conditions No. 25-458-SC]
Special Conditions: Boeing Model 787 Series Airplanes; Single-
place Side-facing Seats With Inflatable Lapbelts
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 Boeing Model 787
series airplanes. These airplanes have a novel or unusual design
feature associated with single-place side-facing seats with inflatable
lapbelts. 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 12,
2012. We must receive your comments by April 23, 2012.
ADDRESSES: Send comments identified by docket number FAA-2012-0311
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: Jeff Gardlin, FAA, Airframe and Cabin
Safety Branch, ANM-115, Transport Airplane Directorate, Aircraft
Certification Service, 1601 Lind Avenue SW., Renton, Washington 98057-
3356; telephone 425-227-2136; 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
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 28, 2003, Boeing Commercial Airplanes applied for an FAA
type certificate for its new Model 787 series airplane (hereafter
referred to as ``787''). The 787 is an all-new, twin-engine jet
transport airplane with a two-aisle cabin which is currently approved
under Type Certificate No. T000215E. The maximum takeoff weight is
476,000 pounds, with a maximum passenger count of 381. These airplanes
have a novel or unusual design feature associated with single-place
side-facing seats with inflatable lapbelts. The inflatable lapbelt 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
lapbelt behaves similarly to an automotive airbag, but in this case the
airbag is integrated into the lapbelt, and inflates away from the
seated occupant. While airbags are now standard in the automotive
industry, the use of an inflatable lapbelt is novel for commercial
aviation.
Title 14, Code of Federal Regulations (14 CFR) 121.311(j) requires
that no person may operate a transport category airplane type
certificated after January 1, 1958, and manufactured on or after
October 27, 2009, in passenger-carrying operations, after October 27,
2009, unless all passenger and flight attendant side-facing seats on an
airplane operated under part 121 rules meet the
[[Page 16911]]
requirements of 14 CFR 25.562 in effect on or after June 16, 1988.
Amendment 25-15 to part 25, dated October 24, 1967, introduced the
subject of side-facing seats and a requirement that each occupant in a
side-facing seat must be protected from head injury by a safety belt
and a cushioned rest that will support the arms, shoulders, head, and
spine.
Subsequently, Amendment 25-20 to part 25, dated April 23, 1969,
clarified the definition of side-facing seats to require that each
occupant of a seat that makes more than an 18 degree angle with the
vertical plane containing the airplane centerline, must be protected
from head injury by a safety belt and an energy absorbing rest that
will support the arms, shoulders, head, and spine, or by a safety belt
and shoulder harness that will prevent the head from contacting any
injurious object. The FAA concluded that an 18-degree angle would
provide an adequate level of safety based on tests that were performed
at that time and thus adopted that standard.
Part 25 was amended June 16, 1988, by Amendment 25-64, to revise
the emergency landing conditions that must be considered in the design
of the airplane. Amendment 25-64 revised the static load conditions in
Sec. 25.561, and added a new Sec. 25.562 that required dynamic
testing for all seats approved for occupancy during takeoff and
landing. The intent of Amendment 25-64 is to provide an improved level
of safety for occupants on transport category airplanes. Because most
seating is forward-facing on transport category airplanes, the pass/
fail criteria developed in Amendment 25-64 focused primarily on these
seats. As a result, the FAA issued Policy Memorandums ANM-03-115-30 and
PS-ANM-100-2000-00123 to provide the additional guidance necessary to
demonstrate the level of safety required by the regulations for side-
facing seats.
The 787, operated under part 121, must meet all of the requirements
of Sec. 25.562 for passenger and flight attendant seats. Therefore it
is in the interest of installers to show full compliance to Sec.
25.562, so that an operator under part 121 may be able to use the
aircraft without having to do additional certification work. It is also
noted that some foreign civil airworthiness authorities have invoked
these same operator requirements in the form of airworthiness
directives.
Section 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 set back 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 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 side-facing seats with inflatable lapbelts, 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. These criteria were to be implemented via special
conditions.
The inflatable lapbelt 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 CFR. Conversely,
inflatable lapbelts 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 lapbelts 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 lapbelt 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. Boeing 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 lapbelt
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 necessary. Other outside influences are lightning and high
intensity radiated fields (HIRF). Existing regulations regarding
lightning, Sec. 25.1316, and existing HIRF special condition for the
787 series airplanes, Special conditions No. 25-354A-SC, are
applicable. Finally, the inflatable lapbelt 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 lapbelt
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 lapbelt differs from traditional occupant protection
systems, and requires special conditions to ensure adequate
performance.
Because the inflatable lapbelt 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 lapbelt. Since an actual crash is frequently composed of
a series of impacts before the airplane comes to rest, this could
[[Page 16912]]
render the inflatable lapbelt 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 lapbelt 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 lapbelt 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 lapbelts that are active.
The inflatable lapbelt 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 lapbelt 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 lapbelt will enhance the brace position. However, the
inflatable lapbelt must not introduce a hazard in that case when
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. Although specifically prohibited by the FAA
operating regulations, the use of the supplementary loop belt (``belly
belt'') may be required by other civil aviation authorities, and should
also be considered with the end goal of meeting those regulations.
Similarly, if the seat is occupied by a pregnant woman, the
installation needs to address such usage, either by demonstrating that
it will function properly, or by adding appropriate limitation on
usage.
Since the inflatable lapbelt 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 lapbelt 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 lapbelt 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
lapbelt 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 lapbelt,
and the inflatable lapbelt is expected to deflate much quicker than ten
seconds.
In addition, during the development of the inflatable lapbelt, the
manufacturer was unable to develop a fabric that would meet the
inflation requirements for the bag and the flammability requirements of
Part I(a)(1)(ii) of appendix F to part 25. The fabrics that were
developed that meet the flammability requirement did not produce
acceptable deployment characteristics. However, the manufacturer was
able to develop a fabric that meets the less stringent flammability
requirements of Part I(a)(1)(iv) of appendix F to part 25 and has
acceptable deployment characteristics.
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 restraint 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 restraints. Since the safety
benefit of the inflatable restraint is very significant, the
flammability standard appropriate for these devices should not screen
out suitable materials, thereby effectively eliminating use of
inflatable restraints. The FAA will need to establish a balance between
the safety benefit of the inflatable restraint and its flammability
performance. At this time, the 2.5-inch per minute horizontal test is
considered to provide that balance. As the state-of-the-art in
materials progresses (which is expected), the FAA may change this
standard in subsequent special conditions to account for improved
materials.
Finally, it should be noted that the special conditions are
applicable to single-place side-facing seats with an inflatable lapbelt
system installed. The special conditions are not an installation
approval. Therefore, while the 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.
Type Certification Basis
Under the provisions of 14 CFR 21.17, Boeing Commercial Airplanes
must show that the 787 series airplanes meet the applicable provisions
of part 25, as amended by Amendments 25-1 through 25-120, 25.125, 25-
125, and 25-128 with the following exception: Sec. 25.1309 remains at
Amendment 25-119 for cargo fire protection systems.
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 787 series airplanes 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 787 series airplanes 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; and the FAA must issue a
finding of regulatory
[[Page 16913]]
adequacy under Sec. 611 of Public Law 92-574, the ``Noise Control Act
of 1972.''
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. 21.17(a)(2).
Novel or Unusual Design Features
The 787 series airplanes incorporate the following novel or unusual
design features: Boeing Commercial Airplanes is installing single-place
side-facing seats with inflatable lapbelts on certain seats of 787
series airplanes, in order to reduce the potential for head and neck
injury in the event of an accident. The inflatable lapbelt works
similar to an automotive airbag, except that the airbag is integrated
with the lapbelt of the restraint system.
The CFR 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 single-place side-facing
seats with inflatable lapbelts. 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 single-
place side-facing seats with inflatable lapbelts.
Accordingly, in addition to the passenger injury criteria specified
in Sec. 25.785, these special conditions are adopted for the 787
series airplanes equipped with single-place side-facing seats with
inflatable lapbelts. 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
lapbelt 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 lapbelt 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 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 lapbelts 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.
Applicability
As discussed above, these special conditions are applicable to the
787 series airplane. Should Boeing Commercial Airplanes 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.
Conclusion
This action affects only certain novel or unusual design features
on 787 series 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 Boeing Model 787 series airplanes.
1. Existing Criteria: All injury protection criteria of Sec.
25.562(c)(1) through (c)(6) apply to the occupant of a side facing
seat. Head Injury Criterion (HIC) assessments are only required for
head contact with the seat and/or adjacent structures.
2. Body-to-Wall/Furnishing Contact: Under the load condition
defined in Sec. 25.562(b)(2), the seat must be installed aft of a
structure such as an interior wall or furnishing that will support the
pelvis, upper arm, chest, and head of an occupant seated next to the
structure. A conservative representation of the structure and its
stiffness must be included in the tests.
3. Thoracic Trauma: Under the load condition defined in Sec.
25.562(b)(2), Thoracic Trauma Index (TTI) injury criterion must be
substantiated by dynamic test or by rational analysis based on previous
test(s) of a similar seat installation. Testing must be conducted with
a Side Impact Dummy (SID), as defined by Title 49 Code of Federal
Regulations (CFR) part 572, subpart F, or its equivalent. TTI must be
less than 85, as defined in 49 CFR part 572, subpart F. The SID TTI
data must be processed as defined in Federal Motor Vehicle Safety
Standard (FMVSS) Sec. 571.214, section S6.13.5.
4. Pelvis: Under the load condition defined in Sec. 25.562(b)(2),
pelvic lateral acceleration must be shown by dynamic test or by
rational analysis based on previous test(s) of a similar seat
installation to not exceed 130g. Pelvic acceleration data must be
processed as defined in FMVSS Sec. 571.214, section S6.13.5.
5. Shoulder Strap Loads: Where upper torso straps (shoulder straps)
are used for occupants, tension loads in individual straps must not
exceed 1,750 pounds. If dual straps are used for restraining the upper
torso, the total strap tension loads must not exceed 2,000 pounds.
6. Neck Injury Criteria: The seating system must protect the
occupant from experiencing serious neck injury.
General Test Guidelines
1. One longitudinal test with the SID Anthropomorphic Test Dummy
(ATD), undeformed floor, no yaw, and with all lateral structural
supports (armrests/walls).
2. Pass/fail injury assessments: TTI and pelvic acceleration. One
longitudinal test with the Hybrid II ATD, deformed floor, with 10
degrees yaw, and with all lateral structural supports (armrests/walls).
Pass/fail injury assessments: HIC, and upper torso restraint load,
restraint system retention and pelvic acceleration.
[[Page 16914]]
3. Vertical (14 G's) test is to be conducted with modified Hybrid
II ATDs with existing pass/fail criteria.
Note: It must be demonstrated that the installation of seats via
plinths or pallets meets all applicable requirements. Compliance
with the guidance contained in FAA Policy Memorandum PS-ANM-100-
2000-00123, dated February 2, 2000, titled ``Guidance for
Demonstrating Compliance with Seat Dynamic Testing for Plinths and
Pallets'' will be acceptable to the FAA.
Inflatable Lapbelt Conditions
If inflatable lapbelts are installed on single-place side-facing
seats, the inflatable lapbelt(s) must meet the final inflatable lapbelt
special conditions (Special Conditions No. 25-431-SC (76 FR 35324, June
17, 2011).
Issued in Renton, Washington, on March 12, 2012.
John Piccola,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service, ANM-100.
[FR Doc. 2012-6957 Filed 3-22-12; 8:45 am]
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