[Federal Register Volume 83, Number 126 (Friday, June 29, 2018)]
[Rules and Regulations]
[Pages 30525-30528]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2018-13999]



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 Rules and Regulations
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 This section of the FEDERAL REGISTER contains regulatory documents 
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  Federal Register / Vol. 83, No. 126 / Friday, June 29, 2018 / Rules 
and Regulations  

[[Page 30525]]



DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 25

[Docket No. FAA-2018-0320; Special Conditions No. 25-731-SC]


Special Conditions: Bombardier Model BD-500-1A10 and BD-500-1A11 
Airplanes, Installation of Inflatable Lap Belts on Seats

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final special conditions; request for comments.

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

SUMMARY: These special conditions are issued for the Bombardier Inc. 
(Bombardier) Model BD-500-1A10 and BD-500-1A11 airplanes. These 
airplanes 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 installation of 
inflatable lap belts on seats. 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: This action is effective on Bombardier on June 29, 2018. Send 
comments on or before August 13, 2018.

ADDRESSES: Send comments identified by Docket No. FAA-2018-0320 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 website, 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).
    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: Alan Sinclair, Airframe and Cabin 
Section, AIR-675, Transport Standards Branch, Policy and Innovation 
Division, Aircraft Certification Service, Federal Aviation 
Administration, 2200 South 216th Street, Des Moines, Washington 98198; 
telephone and fax 206-231-3215; email [email protected].

SUPPLEMENTARY INFORMATION: The substance of these special conditions 
previously has been published in the Federal Register for public 
comment. These special conditions have 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 finds that, for the same 
reason, good cause exists for adopting these special conditions 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 December 6, 2017, Bombardier applied for an amendment to Type 
Certificate No. T00008NY to include the new Model BD-500-1A10 and BD-
500-1A11 airplanes. These airplanes, which are a derivative of the 
Model BD-500 currently approved under Type Certificate No. T00008NY, 
are transport-category, twin-engine airplanes. The BD-500-1A10 has 
seating for 110 to 130 passengers and an estimated maximum take-off 
weight of 129,000 lbs. The BD-500-1A11 has seating for 130-150 
passengers and an estimated maximum take-off weight of 144,000 lbs.

Type Certification Basis

    Under the provisions of title 14, Code of Federal Regulations (14 
CFR) 21.101, Bombardier must show that the Model BD-500-1A10 and BD-
500-1A11 airplanes meet the applicable provisions of the regulations 
listed in Type Certificate No. T00008NY, 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 adequate or 
appropriate safety standards for the Bombardier Model BD-500-1A10 and 
BD-500-1A11 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, or should any other model already included on 
the same

[[Page 30526]]

type certificate be modified 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 Bombardier Model BD-500-1A10 and BD-500-1A11 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.  21.101.

Novel or Unusual Design Features

    The Bombardier Model BD-500-1A10 and BD-500-1A11 airplanes will 
incorporate the following novel or unusual design feature:
    Installation of inflatable lap belts on seats.

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 will employ an automatic inflation mechanism 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. The applicant 
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 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 a pyrotechnic squib.
    To function as 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, 
it could potentially deploy under crash conditions that are not 
sufficiently severe as to require head-injury protection from the 
inflatable lap belt. And 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.
    Given that each occupant's restraint system provides protection for 
that occupant only, the installation must address unoccupied seats. 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 5th 
percentile female to the 95th 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 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 purpose 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.
    The inflatable lap belt will be electrically powered. Likewise, 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 restraint system should function properly if such a

[[Page 30527]]

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. However, the lap-belt bag deflates to absorb energy, so it 
is likely that an inflatable lap belt would be deflated by the time 
passengers begin 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 10 seconds, according to Sec.  25.809(b)(2). 
Therefore, the FAA has established 10 seconds 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 a flight 
attendant would prepare an exit 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 
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 the 
special conditions are not changed at this time. As noted below, the 
method of compliance with the special conditions may involve specific 
considerations when an 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.
    Note 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 must consider the combined effects of all such systems 
installed.
    Bombardier will install inflatable lap belts, a novel design 
feature, on certain seats of their Model BD-500-1A10 and BD-500-1A11 
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 applicant's design 
is integrated into 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 therefore has 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 for Bombardier Model BD-
500-1A10 and BD-500-1A11 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.
    Part I of part 25, appendix F 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 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. Because the safety benefit of the 
inflatable restraint is 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.
    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.

Applicability

    As discussed above, these special conditions are applicable to 
Bombardier Model BD-500-1A10 and BD-500-1A11 airplanes. Should 
Bombardier apply at a later date for a change to the type certificate 
to include another model incorporating the same novel or unusual design 
feature, these special conditions would apply to that model as well.

Conclusion

    This action affects only a certain novel or unusual design feature 
on one model series of airplanes. It is not a rule of general 
applicability.

List of Subjects in 14 CFR Part 25

    Aircraft, Aviation safety, Reporting and recordkeeping 
requirements.

Authority Citation

    The authority citation for these special conditions is as follows:

    Authority:  49 U.S.C. 106(f), 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 Bombardier Model BD-500-1A10 and BD-
500-1A11 airplanes.
    1. The inflatable lap belt must be shown to deploy and provide 
protection under crash conditions where it is necessary to prevent 
serious head

[[Page 30528]]

injury. The means of protection must take into consideration a range of 
stature from a two-year-old child to a 95th 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 an active airbag 
system in the lap belt.
    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, nor 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 inflatable 
lap belt is loosely fastened.
    6. An inadvertent deployment that could cause injury to a standing 
or sitting person must be shown to be improbable.
    7. It must be shown that inadvertent deployment of the airbag 
system in the lap belt, during the most critical part of the flight, 
either will not cause a hazard to the airplane or its occupants, or 
meets the requirement of Sec.  25.1309(b).
    8. The inflatable lap belt must be shown to not impede rapid egress 
of occupants 10 seconds after its deployment.
    9. The inflatable lap-belt 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 airplane 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, section 
I(b)(5).
    15. The airbag system in the lap belt, 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 Des Moines, Washington, on June 25, 2018.
Victor Wicklund,
Manager, Transport Standards Branch, Policy and Innovation Division, 
Aircraft Certification Service.
[FR Doc. 2018-13999 Filed 6-28-18; 8:45 am]
 BILLING CODE 4910-13-P