Special Conditions,; Ballistic Recovery Systems, Modified for Small General Aviation Airplanes

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]

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