[Federal Register Volume 74, Number 211 (Tuesday, November 3, 2009)]
[Rules and Regulations]
[Pages 56702-56706]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E9-26355]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 25

[Docket No. NM419; Special Conditions No. 25-396-SC]


Special Conditions: Airbus Model A340 Series Airplanes; Seats 
With Inflatable Lap Belts

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final special conditions; request for comments.

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SUMMARY: These special conditions are issued for Airbus Model A340 
airplanes. These airplanes, manufactured by Airbus, will have novel or 
unusual design features associated with seats with inflatable lap 
belts. The FAA has issued similar special conditions addressing this 
issue for the Airbus Model A340 series airplanes. 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 November 3, 
2009. We must receive your comments by December 18, 2009.

ADDRESSES: You must mail two copies of your comments to: Federal 
Aviation Administration, Transport Airplane Directorate, Attn: Rules 
Docket (ANM-113), Docket No. NM419, 1601 Lind Avenue, SW., Renton, 
Washington 98057-3356. You may deliver two copies to the Transport 
Airplane Directorate at the above address. You must mark your comments: 
Docket No. NM419. You can inspect comments in the Rules Docket 
weekdays, except Federal holidays, between 7:30 a.m. and 4 p.m.

FOR FURTHER INFORMATION CONTACT: Alan Sinclair, FAA, Airframe and Cabin 
Safety Branch, ANM-115, Transport Airplane Directorate, Aircraft 
Certification Service, 1601 Lind Avenue, SW., Renton, Washington 98057-
3356; telephone (425) 227-2195, facsimile (425) 227-1232.

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 ask 
that you send us two copies of written comments.
    We will file in the docket all comments we receive, as well as a 
report summarizing each substantive public contact with FAA personnel 
about these special conditions. You can inspect the docket before and 
after the comment closing date. If you wish to review the docket in 
person, go to the address in the ADDRESSES section of this preamble 
between 7:30 a.m. and 4 p.m., Monday through Friday, except Federal 
holidays.
    We will consider all comments we receive by the closing date for 
comments. We will consider comments filed late if it is possible to do 
so without incurring expense or delay. We may change these special 
conditions based on the comments we receive.
    If you want us to let you know we received your comments on these 
special conditions, send us a pre-addressed, stamped postcard on which 
the docket number appears. We will stamp the date on the postcard and 
mail it back to you.

Background

    On September 23, 2008, Airbus Industrie, 1 Rond Point Maurice 
Bellonte, 31707 Blagnac, Cedex, France, applied for a design change to 
Type Certificate No. A43NM for installation of inflatable lap belts in 
Airbus Model A340 series airplanes. These special conditions allow 
installation of inflatable lap belts for head-injury protection on 
certain seats in Airbus Model A340 series airplanes. The FAA has issued 
similar special conditions, No. 25-371-SC, on May 7, 2009, for Airbus 
Model A340 series airplanes. These airplanes, currently approved under 
Type Certificate No. A43NM, are swept-wing, conventional-tail, twin-
engine, turbofan-powered, twin-aisle, large-sized, transport-category 
airplanes.
    The inflatable lap belt is designed to limit occupant forward 
excursion if an accident occurs. This will reduce the

[[Page 56703]]

potential for head injury, thereby reducing the Head Injury Criterion 
(HIC) measurement, required by Title 14, Code of Federal Regulations 
(14 CFR), 25.562(c)(5). The inflatable lap belt behaves similarly to an 
automotive inflatable air bag, except that the air bag in the Airbus 
design is integrated into the lap belt and inflates away from the 
seated occupant. While inflatable air bags are now standard in the 
automotive industry, the use of an inflatable lap belt 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 seats on an airplane 
operated under part 121 meet the requirements of Sec.  25.562 in effect 
on or after June 16, 1988.
    The Airbus Model A340 series airplanes, manufactured before October 
27, 2009, operated under part 121, are required to comply with certain 
aspects of Sec.  25.562 as specified per Type Certificate No. A43NM. 
Airbus Model A340 series airplanes manufactured on or after October 27, 
2009, operated under part 121, must meet all of the requirements of 
Sec.  25.562 for passenger and flight-attendant seats. The FAA advises 
installers to show full compliance with Sec.  25.562 so that an 
operator, under part 121, may be able to use the airplane without 
having to do additional certification work. In addition, some foreign 
civil airworthiness authorities have invoked these same operator 
requirements in the form of airworthiness directives.
    Occupants must be protected from head injury, as required by Sec.  
25.785, either by eliminating any injurious object within the striking 
radius of the head, or by installing padding. Traditionally, this has 
required either a setback of 35 inches from any bulkhead or other rigid 
interior feature or, where not practical, the installation of specified 
types of padding. The relative effectiveness of these established means 
of injury protection was not quantified. With the adoption of Amendment 
25-64 to part 25, specifically Sec.  25.562, a new standard was created 
that quantifies required head-injury protection.
    Each seat type design approved for crew or passenger occupancy 
during takeoff and landing, as required by Sec.  25.562, must 
successfully complete dynamic tests or be demonstrated 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 value of a 1,000 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 lap belts, the FAA recognizes 
that appropriate pass/fail criteria need to be developed that fully 
address the safety concerns specific to occupants of these seats.

Type Certification Basis

    Under the provisions of Sec.  21.101 Airbus must show that the A340 
series airplanes, as changed, continue to meet the applicable 
provisions of the regulations incorporated by reference in Type 
Certificate No. A43NM, 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. A43NM are as follows: 14 CFR part 25, 
as amended by Amendments 25-1 through 25-63; certain regulations at 
later Amendments 25-65, 25-66, and 25-77; and Amendment 25-64 with 
exceptions. Refer to Type Certificate Data Sheet (TCDS) A43NM, as 
applicable, for a complete description of the certification basis for 
these models, including certain special conditions that are not 
relevant to these proposed special conditions.
    If the regulations incorporated by reference do not contain 
adequate or appropriate safety standards for the Airbus Model A340 
series airplanes because of a novel or unusual design feature, special 
conditions are prescribed under Sec.  21.16.
    In addition to the applicable airworthiness regulations and special 
conditions, the Airbus Model A340 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.
    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).
    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 or similar 
novel or unusual design feature, or should any other model already 
included on the same type certificate be modified to incorporate the 
same or similar novel or unusual design feature, the special conditions 
would also apply to the other model under Sec.  21.101.

Novel or Unusual Design Features

    Airbus Model A340 series airplanes will incorporate the following 
novel or unusual design features: Seats with inflatable lap belts.

Discussion

    The inflatable lap belt 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, because such devices will likely provide a level of 
safety that exceeds the minimum standards of part 25. Conversely, 
inflatable lap belts 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 to develop standards for this 
design feature.
    The FAA has considered the installation of inflatable lap belts 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 lap belt will rely on electronic sensors for 
signaling and pyrotechnic charges for activation so that it is 
available when needed. These same devices could be susceptible to 
inadvertent activation, causing deployment in a potentially unsafe 
manner. The consequences of such deployment must be considered in 
establishing the reliability of the system. Airbus must substantiate 
that the effects of an inadvertent deployment in flight are either not 
a hazard to the airplane, or that such deployment is an extremely 
improbable occurrence (less than 10-\9\ per flight hour). 
The effect of an inadvertent deployment on a passenger or crewmember 
that might be positioned close to the inflatable lap belt should

[[Page 56704]]

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 HIRF, Sec.  25.1317, are applicable. For 
compliance with those conditions, if inadvertent deployment could cause 
a hazard to the airplane, the inflatable lap belt is considered a 
critical system; if inadvertent deployment could cause injuries to 
persons, the inflatable lap belt should be considered an essential 
system. Finally, the inflatable lap-belt 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.
    For an effective safety system, the inflatable lap belt must 
function properly and must not introduce any additional hazards to 
occupants as a result of its functioning. The inflatable lap belt 
differs variously from traditional occupant-protection systems and 
requires special conditions to ensure adequate performance.
    Because the inflatable lap belt 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 lap belt. Because an actual crash is frequently composed 
of a series of impacts before the airplane comes to rest, this could 
render the inflatable lap belt 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 lap belt installation should be such 
that the inflatable lap belt will 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 will be no requirement for the inflatable 
lap belt to provide protection for multiple impacts.
    Because 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 that unoccupied seats may have lap belts that are active.
    The inflatable lap belt 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 lap-belt 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, so it would not be necessary to show that the 
inflatable lap belt will enhance the brace position. However, the 
inflatable lap belt must not introduce a hazard when it is deployed 
into a seated, braced occupant.
    Another area of concern is the use of seats, so equipped, by 
children whether they are lap-held, sitting 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.
    Because the inflatable lap belt will be electrically powered, the 
system could possibly fail due to a separation in the fuselage. Because 
this system is intended as crash/post-crash protection means, failure 
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
    Because the inflatable lap belt is likely to have a large volume 
displacement, the inflated bag could potentially impede egress of 
passengers. Because the bag deflates to absorb energy, it is likely 
that an inflatable lap belt would be deflated when persons try to leave 
their seats. Nonetheless, it is appropriate to specify a time interval 
after which the inflatable lap belt may not impede rapid egress. The 
maximum time allowed for an exit to open fully after actuation is ten 
seconds, according to Sec.  25.809(b)(2). Therefore 10 seconds was 
chosen as the time interval that the inflatable lap belt must not 
impede rapid egress from the seat after it is deployed. 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 lap belt. The inflatable lap belt will likely deflate much 
more quickly than 10 seconds.
    This potential impediment to rapid egress is even more critical at 
the seats installed in the emergency-exit rows. Installation of the 
inflatable restraints at the Type III exit rows presents different 
egress concerns as compared with front-row seats. However, the need to 
address egress is already part of the special conditions so there is no 
change to the special conditions at this time. As noted below, the 
method of compliance with the special conditions may involve specific 
considerations when the inflatable restraint is installed at Type III 
exits. Section 25.813 clearly requires access to the exit from the main 
aisle in the form of an unobstructed passageway, and no interference in 
opening the exit. The restraint system must not create an impediment to 
the access to, and the opening of, the exit. These lap belts should be 
evaluated in the exit row under existing regulations (Sec. Sec.  25.809 
and 25.813) and guidance material. The inflatable lap belts must also 
be evaluated in post crash conditions, and should be evaluated using 
representative restraint systems in the bag-deployed condition.
    This evaluation would include reviewing the access to, and opening 
of, the exit, specifically for obstructions in the egress path; and any 
interferences in opening the exit. Each unique interior configuration 
must be considered, e.g., passageway width, single or dual passageways 
with outboard seat removed, etc. If the restraint creates any 
obstruction or interference, it is likely that it could impede rapid 
egress from the airplane. In some cases, the passenger is the one who 
will open the exit, such as a Type III over-wing hatch. Project-
specific means-of-compliance guidance is likely necessary if these 
restraint systems are installed at the Type III exit rows.
    Finally, it should be noted that the special conditions are 
applicable to the inflatable lap-belt system as 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 separate, and

[[Page 56705]]

must consider the combined effects of all such systems installed.
    Airbus is proposing to install the following novel or unusual 
design feature of inflatable lap belts on certain seats of Airbus Model 
A340 series airplanes, to reduce the potential for head injury if an 
accident occurs. The inflatable lap belt works similar to an automotive 
inflatable air bag, except that the air bag in the Airbus design is 
integrated with the lap belt of the restraint system.
    The performance criteria for head-injury protection in objective 
terms is stated in Sec.  25.562. However, none of these criteria are 
adequate to address the specific issues raised concerning seats with 
inflatable lap belts. The FAA has therefore determined that, in 
addition to the requirements of part 25, special conditions are needed 
to address requirements particular to the installation of seats with 
inflatable lap belts.
    Accordingly, in addition to the passenger-injury criteria specified 
in Sec.  25.785, these special conditions are proposed for the Airbus 
Model A340 series airplanes equipped with inflatable lap belts. Other 
conditions may be developed, as needed, based on further FAA review and 
discussions with the manufacturer and civil-aviation authorities.
    For a passenger-safety system, the inflatable lap belt is unique in 
that it is both an active and entirely autonomous device. While the 
automotive industry has good experience with inflatable air bags, the 
conditions of use and reliance on the inflatable lap belt as the sole 
means of injury protection are quite different. In automobile 
installations, the air bag is a supplemental system and works in 
conjunction with an upper torso restraint. In addition, the crash event 
is more definable and typically of 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 radiated fields could affect the lap-belt activation 
system.
    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 material types as well 
as use, and have been specified in light of state-of-the-art materials 
available to perform a given function. Without a specific reference, 
the default requirement would apply to the type of material used in 
making the inflatable restraint, which is a fabric in this case. 
However, in writing a special condition, 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. Because the safety benefit of the 
inflatable restraint is very significant, the flammability standard 
appropriate for these devices should not screen out suitable materials 
and thereby effectively eliminate the use of inflatable restraints. The 
FAA must establish a balance between the safety benefit of the 
inflatable restraint and its flammability performance. Presently, 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.
    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 lap belts is a rare event, and because the consequences of 
an inadvertent activation are potentially quite severe, these latter 
requirements are probably more rigorous from a design standpoint.

Applicability

    These special conditions are applicable to the Airbus Model A340 
series airplanes. Should Airbus apply at a later date for a change to 
the type certificates to include another model that incorporates the 
same novel or unusual design feature, or should any other model already 
included on the same type certificate be modified to incorporate the 
same or similar novel or unusual design feature, the special conditions 
would also apply to the other model as well.

Conclusion

    This action affects only certain novel or unusual design features 
on the Airbus Model A340 series airplanes. It is not a rule of general 
applicability, and it affects only Airbus Model A340 series airplanes 
listed on Type Certificate No. A43NM.

List of Subjects in 14 CFR Part 25

    Aircraft, Aviation safety, reporting and recordkeeping 
requirements.

0
The authority citation for these special conditions is as follows:

    Authority: 49 U.S.C. 106(g), 40113, 44701, 44702, 44704.

The Special Conditions

0
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 the Airbus Model A340 series airplanes 
with inflatable lap belts installed.
    1. The inflatable lap belt must be shown to deploy and provide 
protection under crash conditions where it is necessary to prevent 
serious head 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 inflatable lap belt must provide a 
consistent approach to energy absorption throughout that range of 
occupants. In addition, the following situations must be considered.
    The seat occupant is:
     Holding an infant
     A child in a child-restraint device
     A child not using a child-restraint device
     A pregnant woman
    2. The inflatable lap belt must provide adequate protection for 
each occupant regardless of the number of occupants of the seat 
assembly, considering that unoccupied seats may have active seatbelts.
    3. The design must prevent the inflatable lap belt from being 
either incorrectly buckled or incorrectly installed such that the 
inflatable lap belt would not properly deploy. Alternatively, it must 
be shown that such deployment is not hazardous to the occupant, and 
will provide the required head-injury protection.
    4. The inflatable lap-belt system must be shown not to be 
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), likely to be experienced in service.
    5. Deployment of the inflatable lap belt must not introduce injury 
mechanisms to the seated occupant, or result in injuries that could 
impede rapid egress. This assessment should include an occupant who is 
in the brace position when it deploys, and an occupant whose belt is 
loosely fastened.
    6. An inadvertent deployment, that could cause injury to a standing 
or sitting person, must be shown to be improbable.

[[Page 56706]]

    7. Inadvertent deployment of the inflatable lap belt, during the 
most critical part of the flight, must be shown to either not cause a 
hazard to the airplane or be extremely improbable.
    8. The inflatable lap belt must be shown to not impede rapid egress 
of occupants 10 seconds after its deployment.
    9. The system must be protected from lightning and HIRF. The 
threats specified in existing regulations regarding lightning, Sec.  
25.1316, and HIRF, Sec.  25.1317, are incorporated by reference for the 
purpose of measuring lightning and HIRF protection. For the purposes of 
complying with HIRF requirements, the inflatable lap-belt system is 
considered a ``critical system'' if its deployment could have a 
hazardous effect on the airplane; otherwise it is considered an 
``essential'' system.
    10. The inflatable lap belt 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 lap belt does not have to be considered.
    11. The inflatable lap belt must be shown to not release hazardous 
quantities of gas or particulate matter into the cabin.
    12. The inflatable lap-belt installation must be protected from the 
effects of fire such that no hazard to occupants will result.
    13. A means must be available for a crewmember to verify the 
integrity of the inflatable-lap-belt-activation system prior to each 
flight or it must be demonstrated to reliably operate between 
inspection intervals.
    14. The inflatable material may not have an average burn rate of 
greater than 2.5 inches per minute when tested using the horizontal-
flammability test as defined in 14 CFR part 25, appendix F, part I, 
paragraph (b)(5).

Stephen P. Boyd,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. E9-26355 Filed 11-2-09; 8:45 am]
BILLING CODE 4910-13-P