Airworthiness Directives; Boeing Model 747-100, -200, -300, and - 400 Series Airplanes Equipped With BFGoodrich Evacuation Ramp/Slides

DEPARTMENT OF TRANSPORTATION

14 CFR Part 39

[Docket No. 93-NM-106-AD]

Airworthiness Directives; Boeing Model 747-100, -200, -300, and -

400 Series Airplanes Equipped With BFGoodrich Evacuation Ramp/Slides

AGENCY: Federal Aviation Administration, DOT.

ACTION: Supplemental notice of proposed rulemaking; reopening of

comment period.

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SUMMARY: This document revises an earlier proposed airworthiness

directive (AD), applicable to certain Boeing Model 747-100, -200, -300,

and -400 series airplanes, that would have required various

modifications of certain evacuation ramp/slides. That proposal was

prompted by reports of several evacuation ramp/slide malfunctions. This

action revises the proposed rule by adding requirements for additional

modifications of the ramp/slides. The actions specified by this

proposed AD are intended to prevent delayed inflation of evacuation

ramp/slides, which could delay or impede the evacuation of passengers

during an emergency.

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

ADDRESSES: Submit comments in triplicate to the Federal Aviation

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

Attention: Rules Docket No. 93-NM-106-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 the BFGoodrich Company, Aircraft Evacuation Systems,

Sustaining Engineering, D/7916, Phoenix, AZ 85040. This information may

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

Avenue, SW., Renton, Washington; or at the FAA, Transport Airplane

Directorate, Los Angeles Aircraft Certification Office, 3229 East

Spring Street, Long Beach, California.

FOR FURTHER INFORMATION CONTACT: Andrew Gfrerer, Aerospace Engineer,

Systems and Equipment Branch, ANM-131L, FAA, Transport Airplane

Directorate, Los Angeles Aircraft Certification Office, 3229 East

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

5338; 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 93-NM-106-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. 93-NM-106-AD, 1601 Lind Avenue, SW., Renton, Washington

98055-4056.

Discussion

A proposal to amend part 39 of the Federal Aviation Regulations to

add an airworthiness directive (AD), applicable to certain Boeing Model

747-100, -200, -300, and -400 series airplanes, was published as a

notice of proposed rulemaking (NPRM) in the Federal Register on

September 8, 1993 (58 FR 47224). That NPRM would have required various

modifications of certain evacuation ramp/slides. That NPRM was prompted

by reports of several evacuation ramp/slide malfunctions. That

condition, if not corrected, could result in delayed inflation of

evacuation ramp/slides, which could delay or impede the evacuation of

passengers during an emergency.

Two commenters to the proposal, Boeing and BFGoodrich, request that

the proposed rule be revised to require modification of the packboard

and girt. This modification is described in paragraph 2.C. of the

Accomplishment Instructions of BFGoodrich Service Bulletin 7A1418-25-

253, dated April 28, 1993; that service bulletin is cited in the NPRM.

The commenters explain that accomplishment of the modifications

proposed in the NPRM will lower the force required to activate the

slide inflation bottle by a significant amount. Therefore, in order to

prevent accidental inflations during handling, the commenters state

that it is also necessary to modify the packboard and girt. -

The FAA concurs. Paragraph 2.C. of the Accomplishment Instructions

of BFGoodrich service bulletin references Boeing Service Bulletin 747-

25-2885 as the appropriate source of service information for

modification of the packboard and girt. The modification involves

updating the later-style packboards to include a locking device for the

firing lanyard, adding a firing lanyard with a provision for a

packboard lock, and modifying the girt for use with the new firing

lanyard. At the time the NPRM was issued, the FAA planned to issue a

separate AD to address the Boeing service bulletin referenced in

paragraph 2.C. of the Accomplishment Instructions of BFGoodrich service

bulletin. Therefore, the actions described in that paragraph were

excluded from the proposed requirements of the NPRM. However, since the

issuance of the NPRM, the FAA has determined that the modification

requirement specified in that paragraph should be included in this

supplemental NPRM, rather than addressing that modification in a

separate rulemaking action.

In addition, at the time the NPRM was issued, the FAA considered

certain other modifications described in the BFGoodrich service

bulletin to be product improvements. Those modifications are specified

in paragraph 2.G. of the service bulletin, and included adding chafe

patches to the forward end and installing velcro patches between the

girt plies on the units, and adding safety pin locating decals to the

regulator actuator assembly and a protective patch to a clevis/pin

assembly. Since the issuance of the NPRM, the FAA has determined that

these modifications are necessary in order to positively address the

unsafe condition and to enhance the safety and reliability of the

evacuation ramp/slides.

In light of these changes, the FAA has revised paragraph (a) of

this proposed rule to require accomplishment of all paragraphs

specified in the Accomplishment Instructions of BFGoodrich Service

Bulletin 7A1418-25-253, dated April 28, 1993. In addition, ``Note 1''

has been added to this proposal to inform operators that modification

of certain reservoir assemblies, as specified in paragraph 2.D.(1) of

the service bulletin, is required currently by AD 91-25-02, Amendment

39-8103 (56 FR 63629, December 5, 1991).

Since these changes expand the scope of the originally proposed

rule, the FAA has determined that it is necessary to reopen the comment

period to provide additional opportunity for public comment.

There are approximately 1,100 BFGoodrich ramp/slides of the

affected design installed on Boeing Model 747-100, -200, -300, and -400

series airplanes in the worldwide fleet. The FAA estimates that 300 of

these subject ramp/slides are installed on Boeing Model 747-100, -200,

-300, and -400 series airplanes of U.S. registry, and would be affected

by this proposed AD. It would take approximately 22 work hours per

ramp/slide to accomplish the proposed actions, at an average labor rate

of $55 per work hour. Required parts would be provided by the ramp/

slide manufacturer 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 $363,000, or $1,210 per ramp/slide.

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 14

CFR part 39 of the Federal Aviation Regulations 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:

Boeing: Docket 93-NM-106-AD.

Applicability: Model 747-100, -200, -300, and -400 series

airplanes equipped with BFGoodrich evacuation ramp/slides; as listed

in BFGoodrich Service Bulletin 7A1418-25-253, dated April 28, 1993;

certificated in any category.

Compliance: Required as indicated, unless accomplished

previously.

To prevent delayed inflation of evacuation ramp/slides, which

could delay or impede the evacuation of passengers during an

emergency, accomplish the following:

(a) Within 24 months after the effective date of this AD, modify

the door 3 offwing evacuation ramp/slide, part number 7A1418-( ),

in accordance with the Accomplishment Instructions of BFGoodrich

Service Bulletin 7A1418-25-253, dated April 28, 1993, as applicable.

Note 1: Modification of the reservoir assembly (part number

4A3416-1) to the part number 4A3416-3 configuration, as specified in

paragraph 2.D.(1) of the service bulletin, is required currently by

AD 91-25-02, Amendment 39-8103 (56 FR 63629, December 5, 1991).

(b) 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 2: Information concerning the existence of approved

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

obtained from the Los Angeles ACO.

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

Federal Aviation Regulations (FAR) 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 March 9, 1994.

Darrell M. Pederson,

Acting Manager, Transport Airplane Directorate, Aircraft Certification

Service.

[FR Doc. 94-5937 Filed 3-14-94; 8:45 am]

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