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[Federal Register Volume 78, Number 158 (Thursday, August 15, 2013)]
[Rules and Regulations]
[Pages 49655-49660]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2013-19754]

========================================================================
Rules and Regulations
                                                Federal Register
________________________________________________________________________

This section of the FEDERAL REGISTER contains regulatory documents 
having general applicability and legal effect, most of which are keyed 
to and codified in the Code of Federal Regulations, which is published 
under 50 titles pursuant to 44 U.S.C. 1510.

The Code of Federal Regulations is sold by the Superintendent of Documents. 
Prices of new books are listed in the first FEDERAL REGISTER issue of each 
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Federal Register / Vol. 78, No. 158 / Thursday, August 15, 2013 / 
Rules and Regulations

[[Page 49655]]

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 25

[Docket No. FAA-2013-0384; Special Conditions No. 25-495-SC]

Special Conditions: Embraer, S.A., Model EMB-550 Airplane; Side-
Facing Seats; Installation of Airbag Systems in Shoulder Belts

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final special conditions.

-----------------------------------------------------------------------

SUMMARY: These special conditions are issued for the Embraer S.A. Model 
EMB-550 airplane. This airplane will have a novel or unusual design 
feature associated with multiple-place and single-place side-facing 
seats and the installation of airbag systems in the shoulder belts. 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: Effective Date: September 16, 2013.

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 425-227-1232.

SUPPLEMENTARY INFORMATION: 

Background

    On May 14, 2009, Embraer S.A. applied for a type certificate for 
its new Model EMB-550 airplane. The Model EMB-550 airplane is the first 
of a new family of jet airplanes designed for corporate flight, 
fractional, charter, and private owner operations. The airplane has a 
conventional configuration with low wing and T-tail empennage. The 
primary structure is metal with composite empennage and control 
surfaces. The Model EMB-550 airplane is designed for 8 passengers, with 
a maximum of 12 passengers. It is equipped with two Honeywell HTF7500-E 
medium bypass ratio turbofan engines mounted on aft fuselage pylons. 
Each engine produces approximately 6,540 pounds (lbs) of thrust for 
normal takeoff. The primary flight controls consist of hydraulically 
powered fly-by-wire elevators, aileron and rudder, controlled by the 
pilot or copilot sidestick.
    The Model EMB-550 airplane has interior configurations that include 
multiple-place side-facing seats and single-place side-facing seats 
(both referred to as side-facing seats) that include airbag systems in 
the shoulder belts for these seats. Existing regulations do not provide 
adequate or appropriate safety standards for occupants of side-facing 
seats. Also, existing regulations do not provide adequate or 
appropriate safety standards for the addition of airbag systems in the 
shoulder belt of side-facing seats. These special conditions address 
both issues.

Type Certification Basis

    Under the provisions of Title 14, Code of Federal Regulations (14 
CFR) 21.17, Embraer S.A. must show that the Model EMB-550 airplane 
meets the applicable provisions of part 25, as amended by Amendments 
25-1 through 25-127 thereto.
    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 Embraer S.A. Model EMB-550 
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 type certificate for that model be amended 
later to include any other model that incorporates the same or similar 
novel or unusual design feature, the special conditions would also 
apply to the other model under Sec.  21.101.
    In addition to the applicable airworthiness regulations and special 
conditions, the Embraer S.A. Model EMB-550 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 and the FAA must 
issue a finding of regulatory 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 Embraer S.A. Model EMB-550 airplane will incorporate the 
following novel or unusual design features: side-facing seats with 
airbag systems in the shoulder belts.
    The Model EMB-550 airplane will have interior configurations with 
multiple-place side-facing seats and single-place side-facing seats 
that include airbag systems in the shoulder belts. Side-facing seats 
are considered a novel design for transport category airplanes that 
include Amendment 25-64 in their certification basis 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 airbag systems in the 
shoulder belts are designed to limit occupant forward excursion in the 
event of an accident. Using airbag systems in the shoulder belts is 
novel for commercial aviation.

Discussion

    The FAA has been conducting research to develop an acceptable 
method of compliance with Title 14, Code of Federal Regulations (14 
CFR) 25.785(b) for side-facing seat installations. That research has 
identified additional injury considerations and evaluation criteria. 
See published report DOT/FAA/AR-09/41, July 2011.
    Before this research, the FAA had been granting exemptions for the 
multiple-place side-facing seat installations since an adequate method 
of compliance was not available to produce an equivalent level of 
safety to that level of safety provided for the forward- and aft-facing 
seats. These

[[Page 49656]]

exemptions were subject to many conditions that reflected the injury 
evaluation criteria and mitigation strategies available at the time of 
the exemption issuance. The FAA has now developed a methodology to 
address all fully side-facing seats (i.e., seats oriented in the 
aircraft with the occupant facing 90 degrees to the direction of 
aircraft travel) and is documenting those requirements in these special 
conditions. Some of the previous conditions issued for exemptions are 
still relevant and are included in these new special conditions. 
However, many of the conditions for exemption have been replaced by 
different criteria that reflect current research findings.
    The FAA had been issuing special conditions to address single-place 
side-facing seats; however, application of the current research 
findings has allowed issuing special conditions that are applicable to 
all fully side-facing seats, both multiple-place and single-place.
    Neck-injury evaluation methods applicable to the most common side-
facing seat configurations were identified during recent FAA research. 
The scope of that research, however, did not include deriving specific 
injury criteria for all possible loading scenarios that could occur to 
occupants of fully side-facing seats. To limit the injury risk in those 
cases, these special conditions provide conservative injury evaluation 
means that are derived from past practice and applicable scientific 
literature.
    Serious leg injuries, such as femur fractures, can occur in 
aviation side-facing seats that could threaten the occupants' lives 
directly or reduce their ability to evacuate. 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 
injuries. It is believed that the angle of rotation can be determined 
by observing lower-leg flailing in typical high-speed video of the 
dynamic tests. This requirement complies with the intent of the Sec.  
25.562 (b)(6) injury criteria in preventing serious leg injury.
    The requirement to provide support for the pelvis, upper arm, 
chest, and head contained in the previous special conditions for 
single-place side-facing seats, has been replaced in the new special 
conditions applicable to all fully side-facing seats with requirements 
for neck-injury evaluation, leg-flailing limits, pelvis-excursion 
limits, head-excursion limits, and torso lateral-bending limits that 
directly assess the effectiveness of the support provided by the seat 
and restraint system.
    To protect occupants in aft-facing seats, those seats must have 
sufficient height and stiffness to support their heads and spines. 
Providing this support is intended to reduce spinal injuries when 
occupant inertial forces cause their heads and spines to load against 
the seat backs. If, during a side-facing-seat dynamic test, the 
flailing of the occupants causes their heads to translate beyond the 
planes of the seat backs, then this lack of support would not comply 
with the intent of the requirement to prevent spine injuries and would 
not provide the same level of safety afforded occupants of forward- and 
aft-facing seats.
    Results from tests that produced lateral flailing over an armrest 
indicate that serious injuries, including spinal fractures, would 
likely occur. While no criteria currently relates the amount of lateral 
flail to a specific risk of injury, if lateral flexion is limited to 
the normal static range of motion, then the risk of injury should be 
low. This range of motion is approximately 40 degrees from the upright 
position. Ensuring that lateral flexion does not create a significant 
injury risk is consistent with the goal of providing an equivalent 
level of safety to that provided by forward- or aft-facing seats, 
because that type of articulation of those seats does not occur during 
forward impacts.
    Section 25.562 requires that the restraints remain on the shoulders 
and pelvises of the occupants during impact. Advisory Circular (AC) 
25.562-1B, Dynamic Evaluation of Seat Restraint Systems and Occupant 
Protection on Transport Airplanes, dated January 10, 2006, clarifies 
this requirement by stating that restraints must remain on the 
shoulders and pelvises when loaded by the occupants. This criterion is 
necessary to protect the occupants from serious injuries that could be 
caused by lap-belt contact forces applied to soft tissue or by 
ineffectively restraining the upper torsos caused by the upper torso 
restraints sliding off the shoulders. In forward-facing seats (the type 
specifically addressed by that AC), occupant motion during rebound and 
any subsequent re-loading of the belts is limited by interaction with 
the seat backs. However, in side-facing seats subjected to a forward 
impact, the restraint systems may be the only means of limiting the 
occupants' rearward (rebound) motion. So to limit abdominal injury risk 
in side-facing seats, the lap belts must remain on the pelvis 
throughout the impact event, including rebound.
    During side-facing-seat dynamic tests, the risk for head injury is 
assessed with only one occupant size (the 50th percentile male as 
represented by the ES-2re as defined in 49 CFR part 572 supbart U). 
However, protection for a range of occupant statures can be provided if 
the impacted surface is homogenous in the area contactable by that 
range of occupants.
    The FAA has issued special conditions in the past for airbag 
systems on lap belts for some forward-facing seats. These special 
conditions for the airbag systems in the shoulder belts are based on 
the previous special conditions for airbag systems on lap belts with 
some changes to address the specific issues of side-facing seats. 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.
    The FAA has considered the installation of airbag systems in the 
shoulder belts to have two primary safety concerns: first, that the 
systems perform properly under foreseeable operating conditions, and 
second, that the systems do not perform in a manner or at such times as 
would constitute a hazard to the occupants. This latter point has the 
potential to be the more rigorous of the requirements, owing to the 
active nature of the system.
    For the reasons discussed above, 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.

Discussion of Comments

    Notice of proposed special conditions No. 25-13-02-SC for the 
Embraer Model EMB-550 airplanes was published in the Federal Register 
on May 6, 2013 (78 FR 26280). No comments were received, and the 
special conditions are adopted as proposed.

Applicability

    As discussed above, these special conditions are applicable to the 
Embraer Model EMB-550 airplane. Should Embraer S.A. 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 one model of airplanes. It is not a rule of general applicability.

[[Page 49657]]

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 Embraer Model EMB-550 airplanes.
    In addition to the requirements of Sec. Sec.  25.562 and 25.785, 
the following special condition numbers 1 and 2 are part of the type 
certification basis of the Model EMB-550 airplane with side-facing-seat 
installations. For seat places equipped with airbag systems in the 
shoulder belts, additional special condition numbers 3 through 16 are 
part of the type certification basis.
    1. Additional requirements applicable to tests or rational analysis 
conducted to show compliance with Sec. Sec.  25.562 and 25.785 for 
side-facing seats:
    (a) The longitudinal test(s) conducted in accordance with Sec.  
25.562(b)(2) to show compliance with the seat-strength requirements of 
Sec.  25.562(c)(7) and (8) and these special conditions must have an 
ES-2re anthropomorphic test dummy (ATD) (49 CFR part 572 subpart U) or 
equivalent, or a Hybrid-II ATD (49 CFR part 572, subpart B as specified 
in Sec.  25.562) or equivalent occupying each seat position and 
including all items contactable by the occupant (e.g., armrest, 
interior wall, or furnishing) if those items are necessary to restrain 
the occupant. If included, the floor representation and contactable 
items must be located such that their relative position, with respect 
to the center of the nearest seat place, is the same at the start of 
the test as before floor misalignment is applied. For example, if floor 
misalignment rotates the centerline of the seat place nearest the 
contactable item 8 degrees clockwise about the aircraft x-axis, then 
the item and floor representations must be rotated by 8 degrees 
clockwise also to maintain the same relative position to the seat 
place, as shown in Figure 1. Each ATD's relative position to the seat 
after application of floor misalignment must be the same as before 
misalignment is applied. To ensure proper loading of the seat by the 
occupants, the ATD pelvis must remain supported by the seat pan, and 
the restraint system must remain on the pelvis and shoulder of the ATD 
until rebound begins. No injury-criteria evaluation is necessary for 
tests conducted only to assess seat-strength requirements.
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[GRAPHIC] [TIFF OMITTED] TR15AU13.000

    (b) The longitudinal test(s) conducted in accordance with Sec.  
25.562(b)(2) to show compliance with the injury assessments required by 
Sec.  25.562(c) and these special conditions may be conducted 
separately from the test(s) to show structural integrity. In this case, 
structural-assessment tests must be conducted as specified in paragraph 
1(a)

[[Page 49658]]

of these special conditions, and the injury-assessment test must be 
conducted without yaw or floor misalignment. Injury assessments may be 
accomplished by testing with ES-2re ATD (49 CFR part 572 subpart U) or 
equivalent at all places. Alternatively, these assessments may be 
accomplished by multiple tests that use an ES-2re at the seat place 
being evaluated and a Hybrid-II ATD (49 CFR part 572, subpart B, as 
specified in Sec.  25.562) or equivalent used in all seat places 
forward of the one being assessed to evaluate occupant interaction. In 
this case, seat places aft of the one being assessed may be unoccupied. 
If a seat installation includes adjacent items that are contactable by 
the occupant, the injury potential of that contact must be assessed. To 
make this assessment, tests may be conducted that include the actual 
item located and attached in a representative fashion. Alternatively, 
the injury potential may be assessed by a combination of tests with 
items having the same geometry as the actual item but having stiffness 
characteristics that would create the worst case for injury (injuries 
due to both contact with the item and lack of support from the item).
    (c) If a seat is installed aft of a structure (e.g., an interior 
wall or furnishing) that does not have a homogeneous surface 
contactable by the occupant, additional analysis and/or test(s) may be 
required to demonstrate that the injury criteria are met for the area 
which an occupant could contact. For example, different yaw angles 
could result in different injury considerations and may require 
additional analysis or separate test(s) to evaluate.
    (d) To accommodate a range of occupant heights (5th percentile 
female to 95th percentile male), the surface of items contactable by 
the occupant must be homogenous 7.3 inches (185 mm) above and 7.9 
inches (200 mm) below the point (center of area) that is contacted by 
the 50th percentile male size ATD's head during the longitudinal 
test(s) conducted in accordance with paragraphs 1(a), 1(b), and 1(c) of 
these special conditions. Otherwise, additional head-injury criteria 
(HIC) assessment tests may be necessary. Any surface (inflatable or 
otherwise) that provides support for the occupant of any seat place 
must provide that support in a consistent manner regardless of occupant 
stature. For example, if an inflatable shoulder belt is used to 
mitigate injury risk, then it must be demonstrated by inspection to 
bear against the range of occupants in a similar manner before and 
after inflation. Likewise, the means of limiting lower-leg flail must 
be demonstrated by inspection to provide protection for the range of 
occupants in a similar manner.
    (e) For longitudinal test(s) conducted in accordance with Sec.  
25.562(b)(2) and these special conditions, the ATDs must be positioned, 
clothed, and have lateral instrumentation configured as follows:
    (1) ATD positioning:
    (i) Lower the ATD vertically into the seat while simultaneously 
(see Figure 2 for illustration):

[[Page 49659]]

[GRAPHIC] [TIFF OMITTED] TR15AU13.001

    (A) Aligning the midsagittal plane (a vertical plane through the 
midline of the body; dividing the body into right and left halves) with 
approximately the middle of the seat place.
    (B) Applying a horizontal x-axis direction (in the ATD coordinate 
system) force of about 20 pounds (lbs) (89 Newtons [N]) to the torso at 
approximately the intersection of the midsagittal plane and the bottom 
rib of the ES-2re or lower sternum of the Hybrid-II at the midsagittal 
plane, to compress the seat back cushion.
    (C) Keeping the upper legs nearly horizontal by supporting them 
just behind the knees.
    (ii) Once all lifting devices have been removed from the ATD:
    (A) Rock it slightly to settle it in the seat.
    (B) Separate the knees by about 4 inches (100 mm).
    (C) Set the ES-2re's head at approximately the midpoint of the 
available range of z-axis rotation (to align the head and torso 
midsagittal planes).
    (D) Position the ES-2re's arms at the joint's mechanical detent 
that puts them at approximately a 40-degree angle with respect to the 
torso. Position the Hybrid-II ATD hands on top of its upper legs.
    (E) Position the feet such that the centerlines of the lower legs 
are approximately parallel to a lateral vertical plane (in the aircraft 
coordinate system).
    (2) ATD clothing: Clothe each ATD in form-fitting, mid-calf-length 
(minimum) pants and shoes (size 11E) weighing about 2.5 lb (1.1 kg) 
total. The color of the clothing should be in contrast to the color of 
the restraint system. The ES-2re jacket is sufficient for torso 
clothing, although a form-fitting shirt may be used in addition if 
desired.
    (3) ES-2re ATD lateral instrumentation: The rib-module linear 
slides are directional, i.e., deflection occurs in either a positive or 
negative ATD y-axis direction. The modules must be installed such that 
the moving end of the rib module is toward the front of the aircraft. 
The three abdominal force sensors must be installed such that they are 
on the side of the ATD toward the front of the aircraft.
    (f) The combined horizontal/vertical test, required by Sec.  
25.562(b)(1) and these special conditions, must be conducted with a 
Hybrid II ATD (49 CFR part 572, subpart B, as specified in Sec.  
25.562), or equivalent, occupying each seat position.
    (g) Restraint systems:
    (1) If inflatable restraint systems are used, they must be active 
during all dynamic tests conducted to show compliance with Sec.  
25.562.
    (2) The design and installation of seat-belt buckles must prevent 
unbuckling due to applied inertial forces or impact of the hands/arms 
of the occupant during an emergency landing.

[[Page 49660]]

    2. Additional performance measures applicable to tests and rational 
analysis conducted to show compliance with Sec. Sec.  25.562 and 25.785 
for side-facing seats:
    (a) Body-to-body contact: Contact between the head, pelvis, torso, 
or shoulder area of one ATD with the adjacent-seated ATD's head, 
pelvis, torso, or shoulder area is not allowed. Contact during rebound 
is allowed.
    (b) Thoracic: The deflection of any of the ES-2re ATD upper, 
middle, and lower ribs must not exceed 1.73 inches (44 mm). Data must 
be processed as defined in Federal Motor Vehicle Safety Standards 
(FMVSS) 571.214.
    (c) Abdominal: The sum of the measured ES-2re ATD front, middle, 
and rear abdominal forces must not exceed 562 lb (2,500 N). Data must 
be processed as defined in FMVSS 571.214.
    (d) Pelvic: The pubic symphysis force measured by the ES-2re ATD 
must not exceed 1,350 lb (6,000 N). Data must be processed as defined 
in FMVSS 571.214.
    (e) Leg: Axial rotation of the upper-leg (femur) must be limited to 
35 degrees in either direction from the nominal seated position.
    (f) Neck: As measured by the ES-2re ATD and filtered at channel 
frequency class (CFC) 600 as defined in SAE J211:
    (1) The upper-neck tension force at the occipital condyle location 
must be less than 405 lb (1,800 N).
    (2) The upper-neck compression force at the occipital condyle 
location must be less than 405 lb (1,800 N).
    (3) The upper-neck bending torque about the ATD x-axis at the 
occipital condyle location must be less than 1,018 in-lb (115 Nm).
    (4) The upper-neck resultant shear force at the occipital condyle 
location must be less than 186 lb (825 N).
    (g) Occupant (ES-2re ATD) retention: The pelvic restraint must 
remain on the ES-2re ATD's pelvis during the impact and rebound phases 
of the test. The upper-torso restraint straps (if present) must remain 
on the ATD's shoulder during the impact.
    (h) Occupant (ES-2re ATD) support:
    (1) Pelvis excursion: The load-bearing portion of the bottom of the 
ATD pelvis must not translate beyond the edges of its seat's bottom 
seat-cushion supporting structure.
    (2) Upper-torso support: The lateral flexion of the ATD torso must 
not exceed 40 degrees from the normal upright position during the 
impact.
    3. For seats with airbag systems in the shoulder belts, show that 
the airbag systems in the shoulder belts 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 2-year-old child to a 95th percentile male. The 
airbag systems in the shoulder belts must provide a consistent approach 
to energy absorption throughout that range of occupants. When the seat 
systems include airbag systems, the systems must be included in each of 
the certification tests as they would be installed in the airplane. In 
addition, the following situations must be considered:
    (a) The seat occupant is holding an infant.
    (b) The seat occupant is a pregnant woman.
    4. The airbag systems in the shoulder belts must provide adequate 
protection for each occupant regardless of the number of occupants of 
the seat assembly, considering that unoccupied seats may have active 
airbag systems in the shoulder belts.
    5. The design must prevent the airbag systems in the shoulder belts 
from being either incorrectly buckled or incorrectly installed, such 
that the airbag systems in the shoulder belts 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.
    6. It must be shown that the airbag systems in the shoulder belts 
are not susceptible to inadvertent deployment as a result of wear and 
tear, inertial loads resulting from in-flight or ground maneuvers 
(e.g., including gusts and hard landings), and other operating and 
environmental conditions (e.g., vibrations and moisture) likely to 
occur in service.
    7. Deployment of the airbag systems in the shoulder belts must not 
introduce injury mechanisms to the seated occupants or result in 
injuries that could impede rapid egress. This assessment should include 
an occupant whose belt is loosely fastened.
    8. It must be shown that inadvertent deployment of the airbag 
systems in the shoulder belts, 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.
    9. It must be shown that the airbag systems in the shoulder belts 
will not impede rapid egress of occupants 10 seconds after airbag 
deployment.
    10. The airbag systems must be protected from lightning and high-
intensity radiated fields (HIRF). The threats to the airplane specified 
in existing regulations regarding lighting, Sec.  25.1316, and HIRF, 
Sec.  25.1317, are incorporated by reference for the purpose of 
measuring lightning and HIRF protection.
    11. The airbag systems in the shoulder belts 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 systems in the shoulder belts does not 
have to be considered.
    12. It must be shown that the airbag systems in the shoulder belts 
will not release hazardous quantities of gas or particulate matter into 
the cabin.
    13. The airbag systems in the shoulder-belt installations must be 
protected from the effects of fire such that no hazard to occupants 
will result.
    14. A means must be available for a crew member to verify the 
integrity of the airbag systems in the shoulder-belts activation system 
prior to each flight or it must be demonstrated to reliably operate 
between inspection intervals. The FAA considers that the loss of the 
airbag-system deployment function alone (i.e., independent of the 
conditional event that requires the airbag-system deployment) is a 
major-failure condition.
    15. 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).
    16. Once deployed, the airbag systems in the shoulder belts must 
not adversely affect the emergency-lighting system (e.g., block floor 
proximity lights to the extent that the lights no longer meet their 
intended function).

    Issued in Renton, Washington, on August 9, 2013.
Jeffrey E. Duven,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2013-19754 Filed 8-14-13; 8:45 am]
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