[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]


=======================================================================
-----------------------------------------------------------------------

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.

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

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