[Federal Register Volume 59, Number 128 (Wednesday, July 6, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-16233]
[[Page Unknown]]
[Federal Register: July 6, 1994]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 23
[Docket No. 118CE, Special Condition 23-ACE-76]
Special Conditions,; Ballistic Recovery Systems, Modified for
Small General Aviation Airplanes
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final special conditions.
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SUMMARY: These special conditions are being issued for the
supplementary type certification of the Ballistic Recovery Systems,
Inc., parachute recovery system installed in small general aviation
airplanes. This system is referred to as the GARD. Airplanes modified
to use this system will incorporate novel or unusual design features
for which the applicable airworthiness regulations do not contain
adequate or appropriate safety standards. These special conditions
contain the additional airworthiness standards that the Administrator
considers necessary to establish a level of safety equivalent to the
original certification basis for these airplanes.
EFFECTIVE DATE: August 5, 1994.
FOR FURTHER INFORMATION CONTACT:
Lowell Foster, Aerospace Engineer, Standards Office (ACE-100), Small
Airplane Directorate, Aircraft Certification Service, Federal Aviation
Administration, 601 East 12th Street, Kansas City, Missouri, 64106;
telephone (816) 426-5688.
SUPPLEMENTARY INFORMATION:
Background
On January 12, 1987, the Ballistic Recovery System, Inc. (BRS),
9242 Hudson Boulevard, Lake Elmo, Minnesota 55042, filed an application
for a supplemental type certificate (STC) to install the GARD-150
parachute recovery system on Cessna 150/A150 Series and 152/A152 Model
Airplanes. Subsequently, they received the STC under Special Condition
23-ACE-33, dated November 17, 1987. The parachute recovery system is
intended to recover an airplane in emergency situations such as mid-air
collision, loss of engine power, loss of airplane control, sever
structural failure, pilot disorientation, or pilot incapacitation with
a passenger on board. The GARD-150 system, which is only used as a last
resort, is intended to prevent serious injuries to the airplane
occupants by parachuting the airplane to the ground.
BRS followed their STC on the Cessna 150/A150 and 152/A152 Series
with request for special conditions on the General Aviation Recovery
Device (GARD) system that would be applicable to most general aviation
airplanes. The nature of the parachute recovery system applies to most
general aviation airplanes with similar configurations and
characteristics. Separate special conditions for each airplane model
are not needed.
Parachute recovery systems typically consist of a parachute packed
in a canister mounted on the airframe. A solid propellant rocket motor
or compressed air may deploy the canopy and is usually located on the
side of the canister. A door positioned above the canister seals the
canister, parachute canopy, and rocket motor from the elements and
provides free exit when the canopy is deployed. These systems are
deployed by a mechanical pull handle mounted so that the pilot and
passenger can reach it. At least two separate and independent actions
are required to deploy the system.
A multicable bridle attaches the canopy bridle to the airplane
primary structure. The cable lengths are designed to provide the best
airplane touchdown attitude. The cables are routed externally and
covered with small frangible fairings from the fuselage exist holes to
the attach points.
The applicants must supplement the FAA-approved Flight Manual as
part of the STC. The supplement will describe the system, define the
operating envelope with appropriate warnings, and define required
system maintenance and inspection information. A separate FAA-approved
Operating Manual describing the previous items will be provided for
those airplanes that do not have an FAA-approved Flight Manual.
Recommended placards should be located near the pull handle in
clear view of the pilot to identify the system and operating envelope,
state deployment actions, and provide appropriate warnings. A warning
placard should also be located on the canister near the rocket motor.
Discussion
The installation of parachute recovery systems in part 23, VLA, and
primary category airplanes was not envisioned when the certification
basis for these airplanes was established. In addition, the
Administrator has determined that current regulations do not contain
adequate or appropriate safety standards for a parachute recovery
system; therefore, this system is considered a novel and unusual design
feature.
Special conditions may be issued and amended, as necessary, as part
of the type certification basis if the Administrator finds that the
airworthiness standards designated in accordance with Sec. 21.101(b)(1)
do not contain adequate or appropriate safety standards because of the
novel and unusual design features of the airplane modification. Special
conditions, as appropriate, are issued after public notice in
accordance with Sec. 11.49 (as amended October 25, 1989), as required
by Secs. 11.28 and 11.29(b). The special conditions become part of the
type certification basis, as provided by Sec. 21.17(a)(2).
The flight test demonstration requirements will ensure that the
parachute recovery system will perform its intended function without
exceeding its strength capabilities. Demonstrations will be required to
show that the parachute will deploy in various specified flight
conditions.
Occupant restraint requirements will ensure that airplanes modified
with a parachute recovery system are equipped with a restraint system
designed to protect the occupants from injury during parachute
deployment and ground impact.
Requirements for parachute performance will ensure all of the
following: (a) The parachute complies with the applicable section of
TSO-C23c (SAE AS8015A) at the critical airplane weights. (b) The
parachute deployment loads do not exceed the structural strength of the
airplane. (c) The system will provide a ground impact that does not
result in serious injury of the passengers. (d) The system will operate
in adverse weather conditions.
The requirements for the functions and operations of the parachute
recovery system will ensure all of the following: (a) There is no fire
hazard associated with the system. (b) The system has adequate
reliability. (c) The sequence of arming and activating the system will
prevent inadvertent deployment. (d) The system can be activated from
either the pilot's or the copilot's position by various sized people.
(e) The system will be labeled to show its identification function and
operating limitations. (f) It must be shown that the occupants will be
protected from serious injury after touchdown under various adverse
weather conditions, including high winds.
Requirements for protection of the parachute recovery system will
ensure that the system is protected from deterioration due to
weathering, corrosion, abrasion, and other causes; and that provisions
are made to the parachute canister to provide adequate ventilation and
drainage.
Requirements for a system inspection provision will ensure that
adequate means are available to permit examination of the parachute
recovery system components and that instructions for continued
airworthiness are provided.
Requirements for operating limitations of the parachute recovery
system will ensure that the system operating limitations are prescribed
for inspection, repacking, and replacing the system's parachute
deployment mechanism at approved intervals.
Discussion of Comments
Notice of Proposed Special Conditions, Docket No. 118CE, Notice No.
23-ACE-76 (59 FR 2786, January 19, 1994) proposed special conditions
for small general aviation airplanes. The comment period for the notice
closed March 21, 1994. Four comments were received from one commenter.
All comments were concerning the flight portion of these special
conditions.
The commenter believes that the wording of the proposed special
conditions indicates that flight test may be required for each make and
model of aircraft for which the GARD system will be installed. The
commenter does not believe this is necessary for airplanes with similar
characteristics such as configuration, weight, and speed. To support
this position, the commenter cites TSO-C23c for emergency personnel
parachutes that are certified according to suspended weight and maximum
allowable deployment speed. The commenter states that significant
configuration changes would be low wing versus high wing or a change in
the position of the parachute main attach point relative to the
aircraft center of gravity. A significant change in airplane
characteristics could be defined as any variation that could
potentially cause the airplane to react to parachute deployment
different from the original tests.
In this case, a flight demonstration of satisfactory deployment
would be required unless a reliable method of analysis is available.
The FAA agrees with the commenter that the wording of the proposal
infers that the flight demonstrations are required for each airplane
model receiving the STC. This was not the FAA's original intent with
these special conditions. The FAA agrees with the commenter that the
GARD system is intended to add a means of preventing a catastrophic
crash when all other means of recovery are exhausted or made
inoperative. To this end, this system adds to the overall safety of the
airplane. Therefore, the FAA agrees with the commenter's approach to
different airplanes with similar characteristics.
The commenter also believes that special condition 1(b)(3) should
state: Maneuvering speed with 2g normal load, not Og normal load. The
original flight tests included a 60 degree bank turn with a 2g normal
load for one deployment condition. Essentially, the deployment
condition was the airplane turning into the parachute deployment. The
test evaluated both deployment during a turn and the force of the
ballistics to eject the parachute away from the airplane in a way that
would allow it to open. The possible concern was not having enough load
on the parachute to properly inflate the canopy. The results on the
original GARD-150 were satisfactory. The FAA's reason for requiring the
Og test was to evaluate additional deployment loads against the
airframe limits. In re-evaluating this requirement, the FAA believes
that data from static tests and the stall condition deployment will
adequately address the concerns. Additionally, since the 2g test
requirement from the original GARD system was satisfactory, the FAA
finds no reason to evaluate the opening during a 2g turn on each
airplane that requires deployment testing. A 2g acceleration is the
same regardless of the type airplane. If the GARD system had the force
to fire the parachute away from the airplane while the airplane was
turning toward the parachute, then the results should be the same for
other airplanes.
The commenter thought that there should be an option of placarding
the operating limitations as an alternative to testing at the never
exceed speed 1(b)(i)(4) and in inverted flight for aerobatic aircraft
1(b)(ii). Satisfactory deployment would be demonstrated at a maximum
placarded deployment speed with 1g normal load. This maximum placarded
deployment speed should be greater than or equal to the structural
cruising speed of the aircraft.
The FAA conducted a thorough evaluation of the first system to be
STC'd on a certified airplane. The FAA's interest with follow-on
modifications to similar airplanes is primarily to investigate
deployment at the airplane's limits. It is realistic to expect pilots
to deploy this system in an inadvertent spin, at minimum speed (stall),
and at the never exceed speed. By testing at these limits, all
conditions in between are covered. The only exception might be high g
loads from aerobatic airplanes. Any situation where the GARD system is
deployed will either be 1g or less (i.e., normal gliding flight through
spins), or completely unloaded, or tumbling from a structural failure.
It is not reasonable to expect any applicant to test for the tumbling
after a structural failure. In an out-of-control situation (structural
failure), the airplane could quickly reach its never exceed speed. So
the requirement to deploy the GARD system at the never exceed speed
will remain. However, since the argument for aerobatic airplane has
been presented, including the operational reality of an inverted
deployment, the FAA agrees with the commenter that the merits of
requiring the test are far outweighted by the cost to conduct the test.
Therefore, the option of placarding against operating the GARD system
during aerobatics is supported.
Conclusion
In view of the design features discussed for the Ballistic Recovery
Systems General Aviation Recovery Device (GARD), the following special
conditions are issued. This action is a rule of general applicability
and affects small general aviation airplanes with characteristics
similar to those identified in these special conditions.
List of Subjects in 14 CFR Part 23
Aircraft, Aviation safety, and Signs and symbols.
Citation
The authority citation for this special condition is as follows:
Authority: Secs. 313(a), 601, and 603 of the Federal Aviation
Act of 1958; as amended (49 U.S.C. 1354(a), 1421, and 1423); 49
U.S.C. 106(g); 14 CFR 21.16 and 101; and 14 CFR 11.28 and 11.49.
Adoption of Special Condition
Accordingly, pursuant to the authority delegated to me by the
Administrator, the Federal Aviation Administration issues the following
special conditions as part of the supplemental type certification basis
for the BRS GARD system installed in small general aviation airplanes:
1. Flight Test Demonstration
(a) The system must be demonstrated in flight to satisfactorily
perform its intended function, without exceeding the system deployment
load factors, for the critical flight conditions, except as allowed in
1(c).
(b) Satisfactory deployment of the parachute must be demonstrated,
at the most critical airplane weight and balance, for the following
flight conditions:
(1) Power off stall with slow entry,
(2) Spin with deployment at one turn,
(3) Never exceed speed with 1g normal load.
(c) Flight demonstrations are not required for airplanes with
similar characteristics, (such as configuration, weight, and speed) to
airplanes that have already received an STC for the installation. Only
airplanes where a significant change from airplanes that have already
received an STC need to include a flight demonstration. A significant
change in airplane characteristics could be defined as any variation
that could potentially cause the airplane to react to parachute
deployment different from original tests.
2. Occupant Restraint
Each seat in an airplane modified with the parachute recovery
system must be equipped with a restraint system, consisting of a seat
belt and shoulder harness, that will protect the occupants from head
and upper torso injuries during parachute deployment and ground impact
at the critical load conditions.
3. Parachute Performance
(a) The parachute must comply with the applicable requirements of
TSO-C23c, or an approved equivalent, for the critical airplane weights.
(b) The system limit load factor for deployment must not exceed 80
percent of the airplane ultimate load factor.
(c) It must be shown that, although the airplane structure may be
damaged, the airplane impact during touchdown will result in an
occupant environment in which serious injury to the occupants is
improbable.
(d) It must be shown that, with the parachute deployed, the
airplane can impact the ground in various adverse weather conditions,
including winds up to 15 knots, without endangering the airplane
occupants.
4. System Function and Operations
(a) It must be shown that there is no fire hazard associated with
activation of the system.
(b) The system must be shown to function reliably and to perform
its intended function.
(c) It must be shown that arming and activating the system can only
be accomplished in a sequence that makes inadvertent deployment
extremely improbable.
(d) It must be demonstrated that the system can be activated
without difficulty by various sized people, from a 10th percentile
female to a 90th percentile male, while sitting in the pilot or copilot
seat.
(e) The system must be labeled to show its identification,
function, and operating limitations.
(f) It must be shown that the occupants will be protected from
serious injury after touchdown under various adverse weather
conditions, including high winds.
5. System Protection
(a) All components of the system must provide protection against
deterioration due to weathering, corrosion, abrasion, and other causes.
(b) Adequate provisions must be made for ventilation and drainage
of the parachute canister and associated structure to ensure the sound
condition of the system.
6. System Inspection Provisions
(a) Instructions for continued airworthiness must be prepared for
the system that meet the requirements of Sec. 23.1529.
(b) Adequate means must be provided to permit the close examination
of the parachute and other system components to ensure proper
functioning, alignment, lubrication, and adjustment during the required
inspection of the system.
7. Operating Limitations
(a) Operating limitations must be prescribed to ensure proper
operation of the system within the approved flight envelope of the
airplane.
(b) Operating limitations must be prescribed for inspecting,
repacking, and replacing the parachute and deployment mechanism at
approved intervals.
Issued in Kansas City, Missouri on June 22, 1994.
Gerald W. Pierce,
Acting Manager, Small Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 94-16233 Filed 7-5-94; 8:45 am]
BILLING CODE 4910-33-M