81 FR 51095 - Special Conditions: Associated Air Center, Boeing Model 747-8 Airplane; Installation of an Airbag System To Limit the Axial Rotation of the Upper Leg on Single-Place Side-Facing Seats

DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration

Federal Register Volume 81, Issue 149 (August 3, 2016)

These special conditions are issued for the Boeing Model 747- 8 airplane. This airplane, as modified by Associated Air Center, will have a novel or unusual design feature when compared to the state of technology envisioned in the airworthiness standards for transport- category airplanes. This design feature is an airbag system to limit axial rotation of the upper leg, due to leg flail, of occupants in single-place side-facing seats. The applicable airworthiness regulations do not contain adequate or appropriate safety standards for these design features. 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.

[Federal Register Volume 81, Number 149 (Wednesday, August 3, 2016)]
[Rules and Regulations]
[Pages 51095-51097]
From the Federal Register Online  [www.thefederalregister.org]
[FR Doc No: 2016-18398]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 25

[Docket No. FAA-2016-7851; Special Conditions No. 25-625-SC]


Special Conditions: Associated Air Center, Boeing Model 747-8 
Airplane; Installation of an Airbag System To Limit the Axial Rotation 
of the Upper Leg on Single-Place Side-Facing Seats

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 747-
8 airplane. This airplane, as modified by Associated Air Center, will 
have a novel or unusual design feature when compared to the state of 
technology envisioned in the airworthiness standards for transport-
category airplanes. This design feature is an airbag system to limit 
axial rotation of the upper leg, due to leg flail, of occupants in 
single-place side-facing seats. The applicable airworthiness 
regulations do not contain adequate or appropriate safety standards for 
these design features. 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:  This action is effective on Associated Air Center on August 3, 
2016. We must receive your comments by September 19, 2016.

ADDRESSES: Send comments identified by docket number FAA-2016-7851 
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 9 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 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: Jayson Claar, FAA, Airframe and Cabin 
Safety Branch, ANM-115, Transport Airplane Directorate, Aircraft 
Certification Service, 1601 Lind Avenue SW., Renton, Washington 98057-
3356; telephone 425-227-2194; facsimile 425-227-1320.

SUPPLEMENTARY INFORMATION: The substance of these special conditions 
has been subject to the public comment process with no comments 
received. The FAA therefore finds that good cause exists for making 
these special conditions effective upon publication in the Federal 
Register.

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 February 15, 2014, Associated Air Center applied for a 
supplemental type certificate for inflatable airbag systems in the 
Boeing Model 747-8 airplane. This airplane, currently approved under 
type certificate no. A20WE, is a private, not-for-hire, not-for-common-
carriage business jet with a head-of-state interior. This airplane has 
a maximum passenger seating capacity of 113. Twelve of the passenger-
seating positions include single-place side-facing seats, each of which 
include an airbag system to protect against leg-flail injuries.

Type Certification Basis

    Under the provisions of title 14, Code of Federal Regulations (14 
CFR) 21.101, Associated Air Center must show that the Model 747-8 
airplane, as changed, continues to meet the applicable provisions of 
the regulations listed in type certificate no. A20WE, or the applicable 
regulations in effect on the date of application for the change, except 
for earlier amendments as agreed upon by the FAA.
    If the Administrator finds that the applicable airworthiness 
regulations (i.e., 14 CFR part 25) do not contain

[[Page 51096]]

adequate or appropriate safety standards for the Model 747-8 airplane 
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 applicant apply for a supplemental type 
certificate to modify any other model included on the same type 
certificate to incorporate the same novel or unusual design feature, 
these special conditions would also apply to the other model under 
Sec.  21.101.
    In addition to the applicable airworthiness regulations and special 
conditions, the Boeing Model 747-8 airplane 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 Boeing Model 747-8 airplane, as modified by Associated Air 
Center, will incorporate the following novel or unusual design 
features: An airbag system to limit axial rotation of the upper leg, 
due to leg flail, of occupants in single-place side-facing seats.

Discussion

    The Boeing Model 747-8 airplane has an interior configuration that 
includes single-place side-facing seats. These seats include an airbag 
system in the shoulder belt, per Special Conditions no. 25-606-SC; and 
an airbag system to limit the axial rotation of the upper leg (femur).
    Side-facing seats are considered a novel design for transport-
category airplanes that include title 14, Code of Federal Regulations 
(14 CFR) part 25, Amendment 25-64, in their certification bases and 
were not anticipated when those airworthiness standards were issued. 
Therefore, the existing regulations do not provide adequate or 
appropriate safety standards for occupants of side-facing seats. The 
FAA issued Special Conditions no. 25-606-SC to address the 
certification of single- and multiple-place side facing seats for 
Boeing 747-8 airplanes. Those special conditions include condition 
2(e), which requires the axial rotation of the upper-leg (femur) to be 
limited to 35 degrees in either direction from the nominal seat 
position. Associated Air Center has developed an airbag system that 
will be installed close to the floor and that is designed to limit the 
axial rotation of the upper-leg.
    Serious leg injuries, such as femur fracture, can occur in aviation 
side-facing seats, injuries that could threaten the occupant's life 
directly or eliminate the occupant's ability to evacuate the airplane. 
Limiting upper-leg axial rotation to a conservative limit of 35 degrees 
(approximately the 50-percentile range of motion) should also limit the 
risk of serious leg injury. Research suggests that the angle of 
rotation can be determined by observing lower-leg flailing in typical 
high-speed video of the dynamic tests. Alternately, the anthropomorphic 
test dummy could be instrumented to directly measure upper-leg axial 
rotation. This requirement complies with the intent of the Sec.  
25.562(a) injury criteria in preventing serious leg injury.
    To comply with special condition 2(e) on some seat positions, 
Associated Air Center proposes to install leg-flail airbags. This 
airbag is not addressed in Special Conditions no. 25-606-SC. Therefore, 
the FAA must issue new special conditions to address this leg-flail 
airbag installation. These special conditions are similar to other 
special conditions previously issued for airbags.
    Special Conditions no. 25-606-SC for the airbag system in the 
shoulder belt are based on previous special conditions for airbag 
systems on forward-facing seat lap belts with some changes to address 
the specific issues of side-facing seats.
    These special conditions for the leg-flail airbag 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.

Applicability

    As discussed above, these special conditions are applicable to the 
Boeing Model 747-8 airplane as modified by Associated Air Center. 
Should Associated Air Center apply at a later date for a supplemental 
type certificate to modify any other model included on type certificate 
no. A20WE to incorporate the same novel or unusual design feature, 
these special conditions would apply to that model as well.

Conclusion

    This action affects only certain novel or unusual design features 
on one model series of airplanes. It is not a rule of general 
applicability and affects only the applicant who applied to the FAA for 
approval of these features on the airplane.
    The substance of these special conditions previously has been 
subjected to the notice and comment period 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, the FAA has determined that 
prior public notice and comment are unnecessary, and good cause exists 
for adopting these special conditions upon publication in the Federal 
Register. 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 747-8 airplanes modified 
by Associated Air Center.
    In addition to the requirements of Sec. Sec.  25.562 and 25.785, 
and Special Conditions no. 25-606-SC, the following special conditions 
are part of the type certification basis for Boeing 747-8 airplanes 
with leg-flail airbag systems installed on side-facing seats.
    1. For seats with leg-flail airbag systems, these systems must 
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 2-year-old child to a 
95th-percentile male. At some buttock popliteal length and effective 
seat-bottom depth, the lower legs will not be able to form a 90-degree 
angle with the upper leg; at this point, the lower-leg flail would not 
occur. The leg-flail airbag system must provide a consistent approach 
to prevention of leg flail throughout that range of occupants whose 
lower legs can form a 90-degree angle relative to the upper legs when 
seated upright in the seat. Items that need to be considered include, 
but are not limited to, the range of occupants' popliteal height, the 
range of occupants' buttock popliteal length, the design of the seat 
effective height above the floor, and the effective depth of the seat 
bottom cushion.
    2. The leg-flail airbag system must not be susceptible to 
inadvertent

[[Page 51097]]

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 occur in service.
    3. Deployment of the leg-flail airbag system must not introduce 
injury mechanisms to the seated occupant, or result in injuries that 
could impede rapid egress.
    4. Inadvertent deployment of the leg-flail airbag system, during 
the most critical part of the flight, must either meet the requirement 
of Sec.  25.1309(b), or not cause a hazard to the airplane or its 
occupants. This also includes preventing inadvertent airbag deployment 
from a static discharge.
    5. The leg-flail airbag system must not impede rapid egress of 
occupants from the airplane 10 seconds after airbag deployment.
    6. The leg-flail airbag system must be protected from lightning and 
high-intensity radiated fields (HIRF). The threats to the airplane 
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.
    7. The leg-flail airbag system must function properly after loss of 
normal airplane electrical power, and after a transverse separation of 
the fuselage at the most critical location. A separation at the 
location of the leg-flail airbag system does not have to be considered.
    8. The leg-flail airbag system must not release hazardous 
quantities of gas, sharp injurious metal fragments, or particulate 
matter into the cabin.
    9. The leg-flail airbag system installation must be protected from 
the effects of fire such that no hazard to occupants will result.
    10. A means must be available to verify the integrity of the leg-
flail airbag system's activation system prior to each flight, or the 
leg-flail airbag system's activation system must reliably operate 
between inspection intervals. The FAA considers that the loss of the 
leg-flail airbag system's deployment function alone (i.e., independent 
of the conditional event that requires the leg-flail airbag system's 
deployment) is a major-failure condition.
    11. The airbag inflatable material may not have an average burn 
rate of greater than 2.5 inches per minute when tested using the 
horizontal flammability test defined in part 25, appendix F, part I, 
paragraph (b)(5).
    12. The leg-flail airbag system, 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 July 26, 2016.
Victor Wicklund,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2016-18398 Filed 8-2-16; 8:45 am]
 BILLING CODE 4910-13-P