[Federal Register Volume 67, Number 169 (Friday, August 30, 2002)]
[Rules and Regulations]
[Pages 55706-55710]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 02-22118]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 25

[Docket No. NM220; Special Conditions No. 25-210-SC]


Special Conditions: Bombardier Model CL-600-2C10 Series 
Airplanes; Seats With Inflatable Lapbelts

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final special conditions; request for comments.

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SUMMARY: These special conditions are issued for the Bombardier Model 
CL-600-2C10 series airplane. This airplane as modified by Weber 
Aircraft will have a novel or unusual design feature associated with 
inflatable lapbelts. The applicable airworthiness regulations do not 
contain adequate or appropriate safety standards for this design 
feature. These special conditions contain the additional safety 
standards that the Administrator considers necessary to establish a 
level of safety equivalent to that established by the existing 
airworthiness standards.

DATES: The effective date of these special conditions is August 16, 
2002. Comments must be received on or before September 30, 2002.

ADDRESSES: Comments on these special conditions may be mailed in 
duplicate to: Federal Aviation Administration, Transport Airplane 
Directorate, Attn: Rules Docket (ANM-113), Docket No. NM220, 1601 Lind 
Avenue SW., Renton, Washington, 98055-4056; or delivered in duplicate 
to the Transport Airplane Directorate at the above address. Comments 
must be marked: Docket No. NM220 Comments may be inspected in the Rules 
Docket weekdays, except Federal holidays, between 7:30 a.m. and 4 p.m.

FOR FURTHER INFORMATION CONTACT: Mike Thompson, FAA, Airframe and Cabin 
Safety Branch, ANM-115, Transport Airplane Directorate, Aircraft 
Certification Service, 1601 Lind Avenue SW., Renton, Washington 98055-
4056; telephone (425) 227-1157; facsimile (425) 227-1149.

SUPPLEMENTARY INFORMATION:

[[Page 55707]]

FAA's Determination as to Need for Public Process

    The FAA has determined that notice and opportunity for prior public 
comment are unnecessary in accordance with 14 CFR 11.38, because the 
FAA has provided previous opportunities to comment on substantially 
identical special conditions, and has fully considered and addressed 
all the substantive comments received. Based on a review of the comment 
history and the comment resolution the FAA is satisfied that new 
comments are unlikely. The FAA, therefore, finds that good cause exists 
for making these special conditions effective upon issuance.

Comments Invited

    Although this action is in the form of final special conditions 
and, for the reasons stated above, is not preceded by notice and an 
opportunity for public comment, comments are invited on this rule. 
Interested persons are invited to submit 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 
concerning these special conditions. The docket is available for public 
inspection 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 on or before 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 in light of the comments we receive.
    If you want the FAA to acknowledge receipt of your comments on this 
proposal, include with your comments 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

    In a letter dated January 29, 2002, Weber Aircraft applied for a 
supplemental type certificate to install AMSAFE Aviation Inflatable 
Restraints (AAIR) inflatable lapbelts for head injury protection on 
certain seats in Bombardier Model CL-600-2C10 series airplanes. The 
Bombardier Model CL-600-2C10 series airplane is a swept-wing, 
conventional-tail, twin-engine, turbofan-powered transport airplane 
currently approved under Type Certificate No. A21EA. The inflatable 
lapbelt is designed to limit occupant forward movement in the event of 
an accident. This will reduce the potential for head injury, thereby 
reducing the head injury criteria (HIC) calculation. The inflatable 
lapbelt behaves similarly to an automotive inflatable airbag, but in 
this case the airbag is integrated into the lapbelt, and inflates away 
from the seated occupant. While inflatable airbags are now standard in 
the automotive industry, the use of an inflatable lapbelt is novel for 
commercial aviation.
    Title 14 Code of Federal Regulations (14 CFR) 25.785 requires that 
occupants be protected from head injury by either the elimination of 
any injurious object within the striking radius of the head, or by 
padding. Traditionally, this has required a setback of 35 inches from 
any bulkhead or other rigid interior feature or, where that is not 
practical, specified types of padding. The relative effectiveness of 
these means of injury protection had not been quantified. With the 
adoption of Amendment 25-64 to 14 CFR part 25, specifically 
Sec. 25.562, a new standard that quantifies required head injury 
protection was created.
    Section 25.562 specifies that dynamic tests must be conducted for 
each seat type installed in the airplane. In particular, the 
regulations require that persons not suffer serious head injury under 
the conditions specified in the tests, and that a HIC measurement of 
not more than 1000 units be recorded, should contact with the cabin 
interior occur. While the test conditions described in this section of 
the regulations are specific, it is the intent of the requirement that 
an adequate level of head injury protection be provided for crash 
severity up to and including that specified.
    Amendment 25-64 is part of the Bombardier Model CL-600-2C10 series 
airplane certification basis. Therefore, the seat installation with 
inflatable lapbelts must meet the requirement that a HIC measurement of 
less than 1000 be demonstrated for occupants of seats incorporating the 
inflatable lapbelt.
    Because Secs. 25.562 and 25.785 and associated guidance do not 
adequately address seats with inflatable lapbelts, the FAA recognizes 
that appropriate pass/fail criteria that do fully address the safety 
concerns specific to occupants of these seats need to be developed.
    The inflatable lapbelt has two potential advantages over other 
means of head impact protection. First, it can provide significantly 
greater protection than would be expected with energy-absorbing pads, 
and second, it can provide essentially equivalent protection for 
occupants of all statures. These are significant advantages from a 
safety standpoint, since such devices will likely provide a level of 
safety that exceeds the minimum standards of the regulations. 
Conversely, inflatable lapbelts in general are active systems and must 
be relied upon to activate properly when needed, as opposed to an 
energy-absorbing pad or upper torso restraint that is passive, and 
always available. Therefore, the potential advantages must be balanced 
against this and other potential disadvantages in order to develop 
standards that will provide an equivalent level of safety to that 
intended by the regulations.
    The FAA has considered the installation of inflatable lapbelts to 
have two primary safety concerns: first, that they perform properly 
under foreseeable operating conditions, and second, that they do not 
perform in a manner or at such times as would constitute a hazard to 
the airplane or its occupants. This latter point has the potential to 
be the more rigorous of the requirements, owing to the active nature of 
the system. With this philosophy in mind, the FAA has considered the 
following as a basis for the special conditions.
    The inflatable lapbelt will rely on electronic sensors for 
signaling to activate pyrotechnic charges, which then activate the 
lapbelt 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. AMSAFE 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 lapbelt should also be considered. 
The person could be either standing or sitting. A minimum reliability 
level will have to be established for this case, depending upon the 
consequences, even if the effect on the airplane is negligible.
    The potential for an inadvertent deployment could be increased as a 
result of conditions in service. The installation must take ``wear and 
tear'' into account so that the likelihood of an inadvertent deployment 
is not increased

[[Page 55708]]

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 electromagnetic 
fields (HIRF). Since the sensors that trigger deployment are 
electronic, they must be protected from the effects of these threats. 
Existing Special Conditions No. 25-ANM-109 regarding lightning and HIRF 
are therefore applicable. For the purposes of compliance with those 
special conditions, if inadvertent deployment could cause a hazard to 
the airplane, the inflatable lapbelt is considered a critical system. 
If inadvertent deployment could cause injuries to persons, the 
inflatable lapbelt should be considered an essential system. Finally, 
the inflatable lapbelt installation should be protected from the 
effects of fire, so that an additional hazard is not created by, for 
example, a rupture of the pyrotechnic squib.
    In order to be an effective safety system, the inflatable lapbelt 
must function properly and must not introduce any additional hazards to 
occupants as a result of its functioning. There are several areas in 
which the inflatable lapbelt differs from traditional occupant 
protection systems, and requires special conditions to ensure adequate 
performance.
    Because the inflatable lapbelt is essentially a single use device, 
there is the potential that it could deploy under crash conditions that 
are not sufficiently severe to require head injury protection from the 
inflatable lapbelt. Since an actual crash is frequently composed of a 
series of impacts before the airplane comes to rest, this could render 
the inflatable lapbelt useless if a larger impact follows the initial 
impact. This situation does not exist with energy absorbing pads or 
upper torso restraints, which tend to provide protection according to 
the severity of the impact. Therefore, the inflatable lapbelt 
installation should be such that the inflatable lapbelt will provide 
protection when it is required, and will not expend its protection when 
it is not needed. These special conditions contain no requirement for 
the inflatable lapbelt to provide protection from multiple impacts, 
where more than one impact would require protection.
    Since each occupant's restraint system provides protection for that 
occupant only, the installation must address seats that are unoccupied. 
It will be necessary to show that the required protection is provided 
for each occupant regardless of the number of occupied seats, and 
considering that unoccupied seats may have lapbelts that are active.
    Since a wide range of occupants could occupy a seat, the inflatable 
lapbelt should be effective for a wide range of occupants. The FAA has 
historically considered the range from the fifth percentile female to 
the ninety-fifth percentile male as the range of occupants that must be 
taken into account. In this case, the FAA is proposing consideration of 
a broader range of occupants, due to the nature of the lapbelt 
installation and its close proximity to the occupant. In a similar 
vein, these persons could have assumed the brace position, for those 
accidents where an impact is anticipated. Test data indicate that 
occupants in the brace position do not require supplemental protection, 
and so it would not be necessary to show that the inflatable lapbelt 
will enhance the brace position. However, the inflatable lapbelt must 
not introduce a hazard in that case by deploying into the seated, 
braced occupant.
    Another area of concern is the use of inflatable lapbelts in seats 
occupied by children, who could be lap-held, in approved child safety 
seats, or occupying the seat directly. Similarly, if the seat is 
occupied by a pregnant woman, the installation needs to address such 
usage, either by demonstrating that it will function properly, or by 
adding appropriate limitation on usage.
    Since the inflatable lapbelt will be electrically powered, there is 
the possibility that the system could fail due to a separation in the 
fuselage. Since this system is intended as a 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. A separation that 
occurs at the location of the inflatable lapbelt would not have to be 
considered.
    Since the inflatable lapbelt is likely to have a large volume 
displacement, the inflated bag could potentially impede egress of 
passengers. The bag deflates to absorb energy, so it is likely that an 
inflatable lapbelt would be deflated at the time that persons would be 
trying to leave their seats. Nonetheless, it is considered appropriate 
to specify a time interval after which the inflatable lapbelt may not 
impede rapid egress. Ten seconds has been chosen as a reasonable time, 
since this corresponds to the maximum time allowed for an exit to be 
openable. In actuality, it is unlikely that an exit would be prepared 
this quickly in an accident severe enough to warrant deployment of the 
inflatable lapbelt, and the inflatable lapbelt will likely deflate in 
much less than ten seconds.
    Finally, it should be noted that the special conditions are 
applicable to the inflatable lapbelt 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 a separate finding, and must consider the 
combined effects of all such systems installed.

Type Certification Basis

    Under the provisions of Sec. 21.101 Amendment 21-69, effective 
September 16, 1991, Weber Aircraft must show that the Bombardier Model 
CL-600-2C10 series airplane, as changed, continues to meet the 
applicable provisions of the regulations incorporated by reference in 
Type Certificate No. A21EA or the applicable regulations in effect on 
the date of application for the change. Subsequent changes have been 
made to Sec. 21.101 as part of Amendment 21-77, but those changes do 
not become effective until June 10, 2003. 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. A21EA are 14 CFR part 25 dated 
February 1, 1965, including Amendments 25-1 through 25-86, with the 
following exceptions: Section 25.783(f) as amended by Amendment 25-23 
for the cargo compartment door, the main avionics compartment door, and 
the service/emergency door; Sec. 25.571 as amended by Amendment 25-96, 
and Sec. 25.493 as amended by Amendment 25-97. The U.S. type 
certification basis for the Bombardier Model CL-600-2C10 series 
airplanes is established in accordance with Secs. 21.29 and 21.17 and 
the type certification application date. The U.S. type certification 
basis is listed in Type Certificate Data Sheet No. A21AE.
    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 CL-600-2C10 
series airplane because of a novel or unusual design feature, special 
conditions are prescribed under the provisions of Sec. 21.16.
    In addition to the applicable airworthiness regulations and special 
conditions, the Bombardier Model CL-600-2C10 series airplane must 
comply with the fuel vent and exhaust emission requirements of 14 CFR 
part 34 and the

[[Page 55709]]

noise certification requirements of 14 CFR part 36.
    Special conditions, as defined in Sec. 11.19, are issued in 
accordance with Sec. 11.38 and become part of the type certification 
basis in accordance with Sec. 21.101(b)(2) Amendment 21-69, effective 
September 16, 1991.
    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, 
the special conditions would also apply to the other model under the 
provisions of Sec. 21.101(a)(1) Amendment 21-69, effective September 
16, 1991.

Novel or Unusual Design Features

    Weber Aircraft is proposing to install an inflatable lapbelt on 
certain seats of Bombardier CL-600-2C10 series airplanes, in order to 
reduce the potential for head injury in the event of an accident. The 
inflatable lapbelt works similarly to an automotive airbag, except that 
the airbag is integrated with the lap belt of the restraint system. The 
inflatable lapbelts are considered a novel or unusual design feature.
    Federal regulations state the performance criteria for head injury 
protection in objective terms. However, none of these criteria are 
adequate to address the specific issues raised concerning seats with 
inflatable lapbelts. The FAA has therefore determined that, in addition 
to the requirements of part 25, special conditions are needed to 
address requirements particular to installation of seats with 
inflatable lapbelts.
    Accordingly, in addition to the passenger injury criteria specified 
in Sec. 25.785, these special conditions are adopted for the Bombardier 
Model CL-600-2C10 series airplanes equipped with inflatable lapbelts. 
Other special conditions may be developed, as needed, based on further 
FAA review and discussions with the manufacturer and civil aviation 
authorities.

Discussion

    From the standpoint of a passenger safety system, the inflatable 
lapbelt is unique in that it is both an active and entirely autonomous 
device. While the automotive industry has good experience with airbags, 
the conditions of use and reliance on the inflatable lapbelt as the 
sole means of injury protection are quite different. In automobile 
installations, the airbag is a supplemental system and works in 
conjunction with an upper torso restraint. In addition, the crash event 
is more definable and of a typically shorter duration, which can 
simplify the activation logic. The airplane operating environment is 
also quite different from that of automobiles and includes the 
potential for greater ``wear and tear,'' and unanticipated abuse 
conditions (due to galley loading, passenger baggage, etc.). Airplanes 
also operate where exposure to high intensity electromagnetic fields 
could affect the activation system.
    The following special conditions can be characterized as addressing 
either the safety performance of the system or the system's integrity 
against inadvertent activation. Because a crash requiring use of the 
inflatable lapbelts is a relatively rare event, and because the 
consequences of an inadvertent activation are potentially quite severe, 
these latter requirements are probably the more rigorous from a design 
standpoint.

Prior Comment

    One comment was received in response to the most recent publication 
of inflatable lapbelt special conditions (65 FR 60343), which are 
substantially identical to the special conditions contained herein. The 
disposition of this comment is contained in Rules Docket No. NM176 and 
is available for examination by interested parties. In our disposition, 
we agreed with the commenter, but noted that the substance of the 
comment has already been addressed in showing compliance with existing 
regulations during the certification process. Therefore, this comment 
did not result in a change to the special conditions.

Applicability

    As discussed above, these special conditions are applicable to the 
Bombardier Model CL-600-2C10 series airplane. Should Weber Aircraft 
apply at a later date for a supplemental type certificate to modify any 
other model included on Type Certificate No. A21EA to incorporate the 
same novel or unusual design feature, the special conditions would 
apply to that model as well under the provisions of Sec. 21.101(a)(1) 
Amendment 21-69, effective September 16, 1991.

Conclusion

    This action affects only certain novel or unusual design features 
on one model of airplane. It is not a rule of general applicability and 
it affects only the applicant who applied to the FAA for approval of 
these features on the airplane.
    The FAA has determined that notice and opportunity for prior public 
comment are unnecessary in accordance with 14 CFR 11.38, because the 
FAA has provided previous opportunities to comment on substantially 
identical special conditions, and has fully considered and addressed 
all the substantive comments received. Based on a review of the comment 
history and the comment resolution, the FAA is satisfied that new 
comments are unlikely. The FAA, therefore, finds that good cause exists 
for making these special conditions effective upon issuance.

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 Bombardier Model CL-600-2C10 series 
airplanes modified by Weber Aircraft.

Seats With Inflatable Lapbelts

    1. It must be shown that the inflatable lapbelt will 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 lapbelt must provide a consistent 
approach to energy absorption throughout that range. In addition, the 
following situations must be considered:
    a. The seat occupant is holding an infant.
    b. The seat occupant is a child in a child restraint device.
    c. The seat occupant is a child not using a child restraint device.
    d. The seat occupant is a pregnant woman.
    2. The inflatable lapbelt 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 lapbelt from being either 
incorrectly buckled or incorrectly installed so that the inflatable 
lapbelt 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.

[[Page 55710]]

    4. It must be shown that the inflatable lapbelt system is not 
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 lapbelt must not introduce injury 
mechanisms to the seated occupant, or result in injuries that could 
impede rapid egress. This assessment should include consideration of an 
occupant who is in the brace position when it deploys and an occupant 
whose belt is loosely fastened.
    6. It must be shown that an inadvertent deployment that could cause 
injury to a standing or sitting person is improbable.
    7. It must be shown that inadvertent deployment of the inflatable 
lapbelt during the most critical part of the flight will either not 
cause a hazard to the airplane or is extremely improbable.
    8. It must be shown that the inflatable lapbelt will 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 Special Condition No. 25-ANM-109 are incorporated 
by reference for the purpose of measuring lightning and HIRF 
protection. For the purposes of complying with HIRF requirements, the 
inflatable lapbelt 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 lapbelt 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 lapbelt does not have to be considered.
    11. It must be shown that the inflatable lapbelt will not release 
hazardous quantities of gas or particulate matter into the cabin.
    12. The inflatable lapbelt installation must be protected from the 
effects of fire such that no hazard to occupants will result.
    13. There must be a means for a crewmember to verify the integrity 
of the inflatable lapbelt activation system prior to each flight or it 
must be demonstrated to reliably operate between inspection intervals.

    Issued in Renton, Washington, on August 16, 2002.
Ali Bahrami,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 02-22118 Filed 8-29-02; 8:45 am]
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