Airworthiness Directives; Pacific Scientific Company, HTL/KIN- TECH Division, Lap Belt Assemblies and Restraint Systems

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 94-NM-73-AD]

Airworthiness Directives; Pacific Scientific Company, HTL/KIN-

TECH Division, Lap Belt Assemblies and Restraint Systems

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the adoption of a new airworthiness

directive (AD) that is applicable to certain Pacific Scientific lap

belt assemblies and restraint systems. This proposal would require

removal of certain lap belt assemblies and restraint systems, and

replacement with another design assembly. This proposal is prompted by

a report indicating that, subsequent to an accident involving a

transport category airplane, some passengers experienced difficulty in

attempting to release the buckle on their lap belts. The actions

specified by the proposed AD are intended to prevent the inability of

passengers or crew to egress from their seats during an emergency

situation, due to problems associated with the lap belt assembly.

DATES: Comments must be received by July 25, 1994.

ADDRESSES: Submit comments in triplicate to the Federal Aviation

Administration (FAA), Transport Airplane Directorate, ANM-103,

Attention: Rules Docket No. 94-NM-73-AD, 1601 Lind Avenue, SW., Renton,

Washington 98055-4056. Comments may be inspected at this location

between 9 a.m. and 3 p.m., Monday through Friday, except Federal

holidays.

The service information referenced in the proposed rule may be

obtained from Pacific Scientific, HTL/KIN-TECH Division, 22715 Savi

Ranch Parkway, Yorba Linda, California 92687. This information may be

examined at the FAA, Transport Airplane Directorate, 1601 Lind Avenue,

SW., Renton, Washington; or at the FAA, Los Angeles Aircraft

Certification Office, Transport Airplane Directorate, 3229 East Spring

Street, Long Beach, California.

FOR FURTHER INFORMATION CONTACT: Layton Walker, Aerospace Engineer,

Systems & Equipment Branch, ANM-130L, Los Angeles Aircraft

Certification Office, FAA, Transport Airplane Directorate, 3229 East

Spring Street, Long Beach, California 90806-2425; telephone (310) 988-

5339; fax (310) 988-5210.

SUPPLEMENTARY INFORMATION:

Comments Invited -

Interested persons are invited to participate in the making of the

proposed rule by submitting such written data, views, or arguments as

they may desire. Communications shall identify the Rules Docket number

and be submitted in triplicate to the address specified above. All

communications received on or before the closing date for comments,

specified above, will be considered before taking action on the

proposed rule. The proposals contained in this notice may be changed in

light of the comments received.

Comments are specifically invited on the overall regulatory,

economic, environmental, and energy aspects of the proposed rule. All

comments submitted will be available, both before and after the closing

date for comments, in the Rules Docket for examination by interested

persons. A report summarizing each FAA-public contact concerned with

the substance of this proposal will be filed in the Rules Docket.

Commenters wishing the FAA to acknowledge receipt of their comments

submitted in response to this notice must submit a self-addressed,

stamped postcard on which the following statement is made: ``Comments

to Docket Number 94-NM-73-AD.'' The postcard will be date stamped and

returned to the commenter.

Availability of NPRMs -

Any person may obtain a copy of this NPRM by submitting a request

to the FAA, Transport Airplane Directorate, ANM-103, Attention: Rules

Docket No. 94-NM-73-AD, 1601 Lind Avenue, SW., Renton, Washington

98055-4056.

Discussion -

In January 1994, an accident involving a Jetstream Model J4101

airplane occurred in which several surviving passengers experienced

difficulty in removing their lap belts. One passenger indicated that

the plastic release lever on the buckle was difficult to operate and

had to be moved greater than 90 degrees before it would release. The

airplane was destroyed in the post-crash fire, so no evaluation could

be made of the specific lap belts in question. However, the

manufacturer of the lap belt assembly was able to duplicate this

problem at its facility, using a lap belt tester with foam padding

added to simulate soft abdominal flesh. This examination revealed that

the existing buckle design is such that the connector half, when

inserted into the buckle portion, is retained by a raised portion of

the buckle frame. This raised portion is angled 90 degrees to the floor

of the buckle frame. Activation of the buckle lever does not unlatch

the belt, as is common in other designs; rather, activation of the

buckle lever allows the connector to be manually moved up off the

raised portion of the buckle frame and, thus, disconnected. This

disconnecting movement is easily accomplished when done under normal

operating conditions; however, when attempted under certain load

conditions and without prior knowledge of this unique design feature,

the buckle will not release and no amount of lever movement will cause

it to release. This condition, if not corrected, could result in

difficulty for passengers or crew to egress from their seats in an

emergency situation. -

The subject seat buckles have part numbers 1108435 and 1108460;

both are approved under Technical Standard Order (TSO)-C22f. The lap

belt assemblies and restraint systems in which they are used can be

installed on any type of aircraft or rotorcraft. -

The FAA has reviewed and approved Pacific Scientific Service

Bulletin 1108435-25-01, dated April 28, 1994, which describes

procedures for replacing passenger and crew lap belts and restraint

systems that incorporate the P/N 1108435 ``45 degrees'' release lift

lever buckle assembly. The replacement assembly has a modified design

that will improve the lap belt buckle release feature. -

Additionally, the FAA also has reviewed and approved Pacific

Scientific Service Bulletin 1108460-25-01, dated April 28, 1994, which

describes procedures for replacing passenger and crew lap belts and

restraint systems that incorporate the P/N 1108460 ``90 degrees''

release lift lever buckle assembly. This replacement assembly likewise

has a modified design that will improve the lap belt buckle release

feature. -

Since an unsafe condition has been identified that is likely to

exist or develop on other products of this same type design, the

proposed AD would require replacement of the subject lap belt

assemblies and restraint systems with new design assemblies. The

actions would be required to be accomplished in accordance with the

service bulletins described previously. -

There are approximately 27,002 lap belts of the affected design

installed in aircraft and rotorcraft worldwide. The FAA estimates that,

of this number, approximately 10,000 could be installed on U.S.

registered aircraft and rotorcraft. It would take approximately .5 work

hour per lap belt to accomplish the proposed actions, at an average

labor rate of $55 per work hour. Required parts would be supplied by

Pacific Scientific Company at no cost to operators. Based on these

figures, the total cost impact of the proposed AD on U.S. operators is

estimated to be $275,000, or $27.50 per lap belt. -

The total cost impact figure discussed above is based on

assumptions that no operator has yet accomplished any of the proposed

requirements of this AD action, and that no operator would accomplish

those actions in the future if this AD were not adopted. -

The regulations proposed herein would not have substantial direct

effects on the States, on the relationship between the national

government and the States, or on the distribution of power and

responsibilities among the various levels of government. Therefore, in

accordance with Executive Order 12612, it is determined that this

proposal would not have sufficient federalism implications to warrant

the preparation of a Federalism Assessment. -

For the reasons discussed above, I certify that this proposed

regulation (1) is not a ``significant regulatory action'' under

Executive Order 12866; (2) is not a ``significant rule'' under the DOT

Regulatory Policies and Procedures (44 FR 11034, February 26, 1979);

and (3) if promulgated, will not have a significant economic impact,

positive or negative, on a substantial number of small entities under

the criteria of the Regulatory Flexibility Act. A copy of the draft

regulatory evaluation prepared for this action is contained in the

Rules Docket. A copy of it may be obtained by contacting the Rules

Docket at the location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39 -

Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment -

Accordingly, pursuant to the authority delegated to me by the

Administrator, the Federal Aviation Administration proposes to amend

part 39 of the Federal Aviation Regulations (14 CFR part 39) as

follows:

PART 39--AIRWORTHINESS DIRECTIVES -

1. The authority citation for part 39 continues to read as follows:

Authority: 49 U.S.C. App. 1354(a), 1421 and 1423; 49 U.S.C.

106(g); and 14 CFR 11.89.

Sec. 39.13 [Amended]

2. Section 39.13 is amended by adding the following new

airworthiness directive:

Pacific Scientific Company, HTL/Kin-tech Division: Docket 94-NM-73-

AD.

Applicability: Lap belt assemblies and restraint systems, as

listed in Pacific Scientific Service Bulletin 1108435-25-01, dated

April 28, 1994, and Pacific Scientific Service Bulletin 1108460-25-

01, dated April 28, 1994; as installed on aircraft and rotorcraft,

certificated in any category.

Compliance: Required as indicated, unless accomplished

previously.

To prevent the inability of passengers or crew to egress from

their seats during an emergency situation, due to problems

associated with the lap belt assembly, accomplish the following:

(a) Within 90 days after the effective date of this AD, remove

the applicable lap belt assemblies and restraint systems, and

replace them with new design assemblies in accordance with Pacific

Scientific Service Bulletin 1108435-25-01, dated April 28, 1994, or

Pacific Scientific Service Bulletin 1108460-25-01, dated April 28,

1994, as applicable.

(b) As of a date 90 days after the effective date of this AD, no

person shall install on any aircraft or rotorcraft a passenger or

crew lap belt or restraint system (as listed in Pacific Scientific

Service Bulletin 1108435-25-01, dated April 28, 1994, and Pacific

Scientific Service Bulletin 1108460-25-01, dated April 28, 1994)

that incorporates the part number 1108435 ``45 degrees'' release

lift lever buckle assembly, or the part number 1108460 ``90

degrees'' release lift lever buckle assembly.

(c) An alternative method of compliance or adjustment of the

compliance time that provides an acceptable level of safety may be

used if approved by the Manager, Los Angeles Aircraft Certification

Office (ACO), FAA, Transport Airplane Directorate. Operators shall

submit their requests through an appropriate FAA Principal

Maintenance Inspector, who may add comments and then send it to the

Manager, Los Angeles ACO.

Note: Information concerning the existence of approved

alternative methods of compliance with this AD, if any, may be

obtained from the Los Angeles ACO.

(d) Special flight permits may be issued in accordance with

sections 21.197 and 21.199 of the Federal Aviation Regulations (14

CFR 21.197 and 21.199) to operate the airplane to a location where

the requirements of this AD can be accomplished.

Issued in Renton, Washington, on May 24, 1994.

Darrell M. Pederson,

Acting Manager, Transport Airplane Directorate, Aircraft Certification

Service.

[FR Doc. 94-13137 Filed 5-27-94; 8:45 am]

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