[Federal Register Volume 78, Number 176 (Wednesday, September 11, 2013)]
[Rules and Regulations]
[Pages 55629-55632]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2013-22101]
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Rules and Regulations
Federal Register
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Federal Register / Vol. 78, No. 176 / Wednesday, September 11, 2013 /
Rules and Regulations
[[Page 55629]]
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 23
[Docket No. FAA-2013-0781; Special Conditions No. 23-261-SC]
Special Conditions: Cirrus Design Corporation, Model SF50;
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 Cirrus Design
Corporation (Cirrus), model SF50. This airplane will have novel and
unusual design features associated with installation of an inflatable
three-point restraint safety belt with an integrated airbag device at
the pilot and co-pilot seats to include optional installations at other
passenger seat locations. 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 September 11,
2013. We must receive comments by October 11, 2013.
ADDRESSES: Send comments identified by docket number [FAA-2013-0781]
using any of the following methods:
[square] Federal eRegulations Portal: Go to http://www.regulations.gov and follow the online instructions for sending your
comments electronically.
[square] 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.
[square] Hand Delivery of 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.
[square] Fax: Fax comments to Docket Operations at 202-493-2251.
Privacy: The FAA will post all comments it receives, without
change, to http://regulations.gov, including any personal information
the commenter provides. Using the search function of the docket Web
site, anyone can find and read the electronic form of all comments
received into any FAA docket, including the name of the individual
sending the comment (or signing the comment for an association,
business, labor union, etc.). DOT's complete Privacy Act Statement can
be found in the Federal Register published on April 11, 2000 (65 FR
19477-19478), as well as at http://DocketsInfo.dot.gov.
Docket: Background documents or comments received may be read at
http://www.regulations.gov at any time. Follow the online instructions
for accessing the docket or go to the 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: 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.
SUPPLEMENTARY INFORMATION: The FAA has determined that notice and
opportunity for prior public comment is impractical because these
procedures would significantly delay issuance of approval 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 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 ask
that you send us two copies of written comments.
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 based on the comments we receive.
Background
On September 9, 2008, Cirrus applied for a Type Certificate for
their new Model SF50. The SF50 is a single-engine turbofan powered jet
that can carry up to seven occupants.
This aircraft will include a three-point safety belt restraint
system with integrated airbags for the pilot and co-pilot seats. The
aircraft will have airbags as a standard feature on all of the pilot
and copilot seat locations with optional airbags offered at other
passenger locations. Optional locations must meet all applicable
special conditions.
The inflatable restraint systems are a three-point safety belt
restraint system 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 activate the inflator
electronically for deployment.
When activated, 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 based
on providing the same current level of safety as the conventional
certification basis airplane occupant restraint systems. The FAA has
two primary safety concerns with the installation of airbags or
inflatable restraints:
They perform properly under foreseeable operating
conditions; and
They do not perform in a manner or at such times as to
impede the pilot's
[[Page 55630]]
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
and speeds during these phases of flight. The FAA has considered this
when establishing these special conditions.
The inflatable restraint system relies on sensors to activate the
inflator electronically 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. The applicant 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 because 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 airplane 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 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 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
the model SF50 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. Cirrus may
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. Cirrus may show that such deployment is not
hazardous to the occupant and will still provide the required
protection.
The cabin of the Cirrus model SF50 airplane is a confined area 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 should not increase the risk already
associated with fire. Therefore, the inflatable restraint should 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 airbag
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 14 CFR 21.17, Cirrus must show that the
model SF50 meets the applicable provisions of part 23, as amended by
amendment 23-62 thereto.
If the Administrator finds that the applicable airworthiness
regulations (i.e., 14 CFR part 23, Amendment 23-62) do not contain
adequate or appropriate safety standards for the SF50 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 SF50 must comply with the fuel vent and exhaust
emission requirements of 14 CFR part 34, amendment 34-4, and the noise
certification requirements of 14 CFR part 36, amendment 36-28; 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 in accordance with Sec. Sec.
11.19 and 11.38 and they become part of the type certification basis
under Sec. 21.17(a)(2).
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
[[Page 55631]]
design feature, the special conditions would also apply to the other
model.
Novel or Unusual Design Features
The SF50 will incorporate the following novel or unusual design
feature:
A three-point safety belt restraint system incorporating an
inflatable airbag.
Discussion
The SF50 will have novel and unusual design features associated
with installation of an inflatable three-point restraint safety belt
with an integrated airbag device at the pilot and co-pilot seats. The
manufacturer will also offer optional airbags at other passenger
locations. Optional locations must meet all applicable special
conditions. 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 in a manner similar to an automotive airbag.
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 activate the
inflator electronically for deployment.
Section 23.562 states performance criteria for seats and restraints
in an objective manner. However, none of these criteria is adequate to
address the specific issues raised concerning inflatable restraints.
Therefore, the FAA has determined that, in addition to the requirements
of parts 21 and 23, special conditions are needed to address the
installation of this inflatable restraint.
Accordingly, these special conditions are adopted for the Cirrus
Design Corporation Model SF50 airplane 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
model SF50 equipped with the three-point inflatable restraint systems.
Should Cirrus Design Corporation apply at a later date for a change to
the type certificate to include another model incorporating 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 model SF50 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.
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. Therefore, because a delay would
significantly affect the certification of the airplane, which is
imminent, 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
21.17; and 14 CFR 11.19 and 11.38.
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 the Cirrus Design Corporation Model SF
50 airplane.
1. Inflatable Three-Point Restraint Safety Belt with an Integrated
Airbag Device
a. It must be shown that the inflatable restraint will deploy and
provide protection under crash conditions. Compliance will be
demonstrated using the dynamic test condition specified in 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.
b. The inflatable restraint must provide adequate protection for
each occupant. In addition, unoccupied seats that have an active
restraint must not constitute a hazard to any occupant.
c. 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.
d. It must be shown that the inflatable restraint 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) that are likely to be experienced in service.
e. 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.
f. It must be shown that deployment of the inflatable restraint
system is not hazardous to the occupant or result in injuries that
could impede rapid egress. This assessment should include occupants
whose restraint is loosely fastened.
g. 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 provide suitable visual warnings that would alert rescue
personnel to the presence of an inflatable restraint system.
h. It must be shown that the inflatable restraint will not impede
rapid egress of the occupants 10 seconds or later after its deployment.
i. For the purposes of complying 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.
j. It must be shown that the inflatable restraints will not release
hazardous quantities of gas or particulate matter into the cabin.
k. The inflatable restraint system installation must be protected
from the effects of fire such that no hazard to occupants will result.
l. There must be a means to verify the integrity of the inflatable
restraint activation system prior to each flight or it must be
demonstrated to reliably operate between inspection intervals.
m. A life limit must be established for appropriate system
components.
n. Qualification testing of the internal firing mechanism must be
performed at
[[Page 55632]]
vibration levels appropriate for a general aviation airplane.
Issued in Kansas City, Missouri on September 4, 2013.
Earl Lawrence,
Manager, Small Airplane Directorate, Aircraft Certification Service.
[FR Doc. 2013-22101 Filed 9-10-13; 8:45 am]
BILLING CODE 4910-13-P