[Federal Register Volume 76, Number 146 (Friday, July 29, 2011)]
[Rules and Regulations]
[Pages 45399-45402]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2011-19157]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 23

[Docket No. CE312; Special Conditions No. 23-252-SC]


Special Conditions: Cessna Aircraft Company, Model LC40-550FG, 
LC41-550FG, and LC42-550FG; AmSafe Inflatable Three-Point Restraint 
Safety Belt With an Integrated Airbag Device

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 installation of an 
inflatable three-point restraint safety belt with an integrated airbag 
device at the pilot, co-pilot and passenger seats on the Cessna 
Aircraft Company airplane models LC40-550FG, LC41-550FG, and LC42-
550FG. These airplanes, as modified by the installation of these 
inflatable safety belts, will have novel and unusual design features 
associated with the upper-torso restraint portions of the three-point 
safety belts, which contain an integrated airbag device. 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 July 21, 2011.
    We must receive your comments on or before August 29, 2011.

ADDRESSES: Mail two copies of your comments to: Federal Aviation 
Administration (FAA), Regional Counsel, ACE-7, Attention: Rules Docket, 
Docket No. CE312, 901 Locust, Room 506, Kansas City, Missouri 64106. 
You may deliver two copies to the Regional Counsel at the above 
address. Mark your comments: Docket No. CE312. You may inspect comments 
in the Rules Docket weekdays, except Federal holidays, between 7:30 
a.m. and 4 p.m.

FOR FURTHER INFORMATION CONTACT: Mr. Bob Stegeman, Federal Aviation 
Administration, Aircraft Certification Service, Small Airplane 
Directorate, ACE-111, 901 Locust, Kansas City, Missouri, 816-329-4140, 
fax 816-329-4090, e-mail [email protected].

SUPPLEMENTARY INFORMATION: The FAA has determined that notice and 
opportunity for prior public comment hereon are impracticable because 
these procedures would significantly delay issuance of the approval 
design and thus delivery of the affected aircraft. In addition, the 
substance of these special conditions has been subject to the public 
comment process in several prior instances with no substantive comments 
received. The FAA, therefore, finds that good cause exists for making 
these special conditions effective upon issuance.

Comments Invited

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

Background

    On February 3, 2011, AmSafe, Inc. applied for a Supplemental Type 
Certificate (STC), for the installation of a three-point safety belt 
restraint system for the pilot, co-pilot and the passenger seats, each 
incorporating inflatable airbags, for model LC40-550FG, LC41-550FG, and 
LC42-550FG airplanes.
    The inflatable restraint systems are: Three-point safety belt 
restraint systems consisting of a lap belt and shoulder harness with an 
inflatable airbag attached to the lap belt. The inflatable portion of 
the restraint system will rely on sensors to electronically activate 
the inflator for deployment.
    If an emergency landing occurs, the airbags will inflate and 
provide a protective cushion between the occupant's head and the 
structure within the airplane. This will reduce the potential for head 
and torso injury. The inflatable restraint behaves in a manner similar 
to an automotive airbag; however, in this case, the airbag is 
integrated into the lap belt. While airbags and inflatable restraints 
are standard in the automotive industry, the use of an inflatable 
restraint system is novel for general aviation operations.
    The FAA has determined that this project will be accomplished on 
the basis of providing the same current level of safety as the 
conventional certification basis airplane occupant

[[Page 45400]]

restraint systems. The FAA has two primary safety concerns with the 
installation of airbags or inflatable restraints:
     That they perform properly under foreseeable operating 
conditions; and
     That they do not perform in a manner or at such times as 
to impede the pilot's ability to maintain control of the airplane or 
constitute a hazard to the airplane or occupants.
    The latter point has the potential to be the more rigorous of the 
requirements. An unexpected deployment while conducting the takeoff or 
landing phases of flight may result in an unsafe condition. The 
unexpected deployment may either startle the pilot or generate a force 
sufficient to cause a sudden movement of the control yoke. Either 
action could result in a loss of control of the airplane, the 
consequences of which are magnified due to the low operating altitudes 
during these phases of flight. The FAA has considered this when 
establishing these special conditions.
    The inflatable restraint system relies on sensors to electronically 
activate the inflator for deployment. These sensors could be 
susceptible to inadvertent activation, causing deployment in a 
potentially unsafe manner. The consequences of an inadvertent 
deployment must be considered in establishing the reliability of the 
system. AmSafe, Inc. must show that the effects of an inadvertent 
deployment in flight are not a hazard to the airplane or that an 
inadvertent deployment is extremely improbable. In addition, general 
aviation aircraft are susceptible to a large amount of cumulative wear 
and tear on a restraint system. The potential for inadvertent 
deployment may increase as a result of this cumulative damage. 
Therefore, the impact of wear and tear on inadvertent deployment must 
be considered. The effect of this cumulative damage means a life limit 
must be established for the appropriate system components in the 
restraint system design.
    There are additional factors to be considered to minimize the 
chances of inadvertent deployment. General aviation airplanes are 
exposed to a unique operating environment, since the same airplane may 
be used by both experienced and student pilots. The effect of this 
environment on inadvertent deployment must be understood. Therefore, 
qualification testing of the firing hardware/software must consider the 
following:
     The airplane vibration levels appropriate for a general 
aviation airplane; and
     The inertial loads that result from typical flight or 
ground maneuvers, including gusts and hard landings.

Any tendency for the firing mechanism to activate as a result of these 
loads or acceleration levels is unacceptable.

    Other influences on inadvertent deployment include high intensity 
electromagnetic fields (HIRF) and lightning. Since the sensors that 
trigger deployment are electronic, they must be protected from the 
effects of these threats. To comply with HIRF and lightning 
requirements, the AmSafe, Inc. inflatable restraint system is 
considered a critical system, since its inadvertent deployment could 
have a hazardous effect on the airplane.
    Given the level of safety of the occupant restraints currently 
installed, the inflatable restraint system must show that it will offer 
an equivalent level of protection for an emergency landing. If an 
inadvertent deployment occurs, the restraint must still be at least as 
strong as a Technical Standard Order approved belt and shoulder 
harnesses. There is no requirement for the inflatable portion of the 
restraint to offer protection during multiple impacts, where more than 
one impact would require protection.
    The inflatable restraint system must deploy and provide protection 
for each occupant under an emergency landing condition. The seats of 
LC40-550FG, LC41-550FG, and LC42-550FG model airplanes are certificated 
to the structural requirements of Sec.  23.562; therefore, the test 
emergency landing pulses identified in Sec.  23.562 must be used to 
satisfy this requirement.
    A wide range of occupants may use the inflatable restraint; 
therefore, the protection offered by this restraint should be effective 
for occupants that range from the fifth percentile female to the 
ninety-fifth percentile male. Energy absorption must be performed in a 
consistent manner for this occupant range.
    In support of this operational capability, there must be a means to 
verify the integrity of this system before each flight. AmSafe, Inc. 
must establish inspection intervals where they have demonstrated the 
system to be reliable between these intervals.
    An inflatable restraint may be ``armed'' even though no occupant is 
using the seat. While there will be means to verify the integrity of 
the system before flight, it is also prudent to require unoccupied 
seats with active restraints not constitute a hazard to any occupant. 
This will protect any individual performing maintenance inside the 
cockpit while the aircraft is on the ground. The restraint must also 
provide suitable visual warnings that would alert rescue personnel to 
the presence of an inflatable restraint system.
    In addition, the design must prevent the inflatable seatbelt from 
being incorrectly buckled and/or installed such that the airbag would 
not properly deploy. AmSafe, Inc. must show that such deployment is not 
hazardous to the occupant and will still provide the required 
protection.
    The cabins of the Cessna model airplanes identified in these 
special conditions are confined areas, and the FAA is concerned that 
noxious gasses may accumulate if the airbag deploys. When deployment 
occurs, either by design or inadvertently, there must not be a release 
of hazardous quantities of gas or particulate matter into the cockpit.
    An inflatable restraint must not increase the risk already 
associated with fire. Therefore, the inflatable restraint must be 
protected from the effects of fire to avoid creating an additional 
hazard by, for example, a rupture of the inflator.
    Finally, the airbag is likely to have a large volume displacement, 
and possibly impede the egress of an occupant. Since the bag deflates 
to absorb energy, it is likely that the inflatable restraint would be 
deflated at the time an occupant would attempt egress. However, it is 
appropriate to specify a time interval after which the inflatable 
restraint may not impede rapid egress. Ten seconds has been chosen as 
reasonable time. This time limit will offer a level of protection 
throughout the impact event.

Type Certification Basis

    Under the provisions of Sec.  21.101, AmSafe, Inc. must show that 
the LC40-550FG, LC41-550FG, and LC42-550FG model airplanes continue to 
meet the applicable provisions of the applicable regulations in effect 
on the date of application for the type certificate. The regulations 
incorporated by reference in the type certificate are commonly referred 
to as the ``original type certification basis.'' The following model is 
covered by this special condition:

Cessna Aircraft Company Models LC40-550FG, LC41-550FG, and LC42-550FG

    For the models listed above, the certification basis also includes 
all exemptions, if any; equivalent level of safety findings, if any; 
and special conditions not relevant to the special conditions adopted 
by this rulemaking action.

[[Page 45401]]

    If the Administrator determines that the applicable airworthiness 
regulations (i.e., part 23 as amended) do not contain adequate or 
appropriate safety standards for the AmSafe, Inc., inflatable restraint 
as installed on these Cessna Aircraft Company models because of a novel 
or unusual design feature, special conditions are prescribed under the 
provisions of Sec.  21.16.
    Special conditions, as appropriate, 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.
    Special conditions are initially applicable to the models 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 that model under the 
provisions of Sec.  21.101.

Novel or Unusual Design Features

    The Cessna Aircraft Company LC40-550FG, LC41-550FG, and LC42-550FG 
model airplanes will incorporate the following novel or unusual design 
feature: A three-point safety belt restraint system incorporating an 
inflatable airbag for the pilot, co-pilot, and passenger seats.
    The purpose of the airbag is to reduce the potential for injury in 
the event of an accident. In a severe impact, an airbag will deploy 
from the lap belt. The airbag will deploy between the head of the 
occupant and airplane interior structure, which will provide some 
protection to the head of the occupant. The restraint will rely on 
sensors to electronically activate the inflator for deployment.
    The Code of Federal Regulations states performance criteria for 
seats and restraints in an objective manner. However, none of these 
criteria are adequate to address the specific issues raised concerning 
inflatable restraints. Therefore, the FAA has determined that, in 
addition to the requirements of part 21 and part 23, special conditions 
are needed to address the installation of this inflatable restraint.
    Accordingly, these special conditions are adopted for the Cessna 
Aircraft Company LC40-550FG, LC41-550FG, and LC42-550FG model airplanes 
equipped with three-point inflatable restraints. Other conditions may 
be developed, as needed, based on further FAA review and discussions 
with the manufacturer and civil aviation authorities.

Applicability

    As discussed above, these special conditions are applicable to the 
Cessna Aircraft Company, LC40-550FG, LC41-550FG, and LC42-550FG model 
airplanes equipped with the three or four-point inflatable restraint 
systems.

Conclusion

    This action affects only certain novel or unusual design features 
on the previously identified Cessna Aircraft Company model airplanes. 
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.
    Under standard practice, the effective date of final special 
conditions would be 30 days after the date of publication in the 
Federal Register; however, the substance of these special conditions 
has been subjected to the notice and comment period in several prior 
instances 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. For 
this reason, and because a delay would significantly affect the 
delivery of the airplane(s), the FAA has determined that prior public 
notice and comment are unnecessary and impracticable, and good cause 
exists for adopting these special conditions upon issuance. 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 23

    Aircraft, Aviation safety, Signs and symbols.

Citation

    The authority citation for these special conditions is as follows:

    Authority:  49 U.S.C. 106(g), 40113 and 44701; 14 CFR 21.16 and 
21.101; and 14 CFR 11.38 and 11.19.

The Special Conditions

    The FAA has determined that this project will be accomplished on 
the basis of not lowering the current level of safety of the Cessna 
Aircraft Company LC40-550FG, LC41-550FG, and LC42-550FG model occupant 
restraint systems. 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 this model.

Inflatable Three-Point Restraint Safety Belt With an Integrated Airbag 
Device on the Pilot, Co-Pilot, and Passenger Seats of the Cessna 
Aircraft Company LC40-550FG, LC41-550FG, and LC42-550FG Model Airplanes

    1. It must be shown that the inflatable restraint will deploy and 
provide protection under emergency landing conditions. Compliance will 
be demonstrated using the dynamic test condition specified in 14 CFR, 
part 23, Sec.  23.562(b)(2). It is not necessary to account for floor 
warpage, as required by Sec.  23.562(b)(3), or vertical dynamic loads, 
as required by Sec.  23.562(b)(1). The means of protection must take 
into consideration a range of stature from a 5th percentile female to a 
95th percentile male. The inflatable restraint must provide a 
consistent approach to energy absorption throughout that range.
    2. Unoccupied seats that have an active restraint must not 
constitute a hazard to any occupant.
    3. The design must prevent the inflatable restraint from being 
incorrectly buckled and/or incorrectly installed such that the airbag 
would not properly deploy. Alternatively, it must be shown that such 
deployment is not hazardous to the occupant and will provide the 
required protection.
    4. It must be shown that the inflatable restraint system is not 
susceptible to inadvertent deployment as a result of wear and tear or 
the inertial loads resulting from in-flight or ground maneuvers 
(including gusts and hard landings) that are likely to be experienced 
in service.
    5. It must be extremely improbable for an inadvertent deployment of 
the restraint system to occur, or an inadvertent deployment must not 
impede the pilot's ability to maintain control of the airplane or cause 
an unsafe condition (or hazard to the airplane). In addition, a 
deployed inflatable restraint must be at least as strong as a Technical 
Standard Order (C114) certificated belt and shoulder harness.
    6. It must be shown that deployment of the inflatable restraint 
system is not hazardous to the occupant or will not result in injuries 
that could impede rapid egress. This assessment must include occupants 
whose restraint is loosely fastened.
    7. It must be shown that an inadvertent deployment that could cause 
injury to a standing or sitting person is improbable. In addition, the 
restraint must also provide suitable visual warnings that would alert 
rescue

[[Page 45402]]

personnel to the presence of an inflatable restraint system.
    8. It must be shown that the inflatable restraint will not impede 
rapid egress of the occupants 10 seconds after its deployment.
    9. To comply with HIRF and lightning requirements, the inflatable 
restraint system is considered a critical system since its deployment 
could have a hazardous effect on the airplane.
    10. It must be shown that the inflatable restraints will not 
release hazardous quantities of gas or particulate matter into the 
cabin.
    11. The inflatable restraint system installation must be protected 
from the effects of fire such that no hazard to occupants will result.
    12. There must be a means to verify the integrity of the inflatable 
restraint activation system before each flight or it must be 
demonstrated to reliably operate between inspection intervals.
    13. A life limit must be established for appropriate system 
components.
    14. Qualification testing of the internal firing mechanism must be 
performed at vibration levels appropriate for a general aviation 
airplane.

    Issued in Kansas City, Missouri, on July 21, 2011.
Earl Lawrence,
Manager, Small Airplane Directorate, Aircraft Certification Service.
[FR Doc. 2011-19157 Filed 7-28-11; 8:45 am]
BILLING CODE 4910-13-P