Airworthiness Directives; Boeing Model 747-400 Series Airplanes Equipped With BFGoodrich Evacuation Slide/Rafts

DEPARTMENT OF AGRICULTURE

DEPARTMENT OF TRANSPORTATION

14 CFR Part 39

[Docket No. 95-NM-218-AD]

RIN 2120-AA64

Airworthiness Directives; Boeing Model 747-400 Series Airplanes

Equipped With BFGoodrich Evacuation Slide/Rafts

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 Boeing Model 747-400

series airplanes. This proposal would require modification of door 5

evacuation slide/rafts. This proposal is prompted by reports that the

door 5 evacuation slide/raft failed to deploy properly due to adverse

loads caused by the geometry of this evacuation slide/raft. The actions

specified by the proposed AD are

[[Page 18706]]

intended to prevent failure of the door 5 evacuation slide/raft to

deploy properly, which could contribute to injury of passengers on the

slide and could delay or impede the evacuation of passengers during an

emergency.

DATES: Comments must be received by June 10, 1996.

ADDRESSES: Submit comments in triplicate to the Federal Aviation

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

Attention: Rules Docket No. 95-NM-218-AD, 1601 Lind Avenue, SW.,

Renton, Washington 98055-4056. Comments may be inspected at this

location between 9:00 a.m. and 3:00 p.m., Monday through Friday, except

Federal holidays.

The service information referenced in the proposed rule may be

obtained from BFGoodrich Company, Aircraft Evacuation Systems,

Department 7916, Phoenix, Arizona 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, 3960 Paramount Boulevard,

Lakewood, California.

FOR FURTHER INFORMATION CONTACT: Andrew Gfrerer, Aerospace Engineer,

Systems and Equipment Branch, ANM-130L, FAA, Los Angeles Aircraft

Certification Office, 3960 Paramount Boulevard, Lakewood, California

90712; telephone (310) 627-5338; fax (310) 627-5210.

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 95-NM-218-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. 95-NM-218-AD, 1601 Lind Avenue, SW., Renton, Washington

98055-4056.

Discussion

The FAA has received reports indicating that the door 5 evacuation

slide/raft installed on Boeing Model 747-400 series airplanes failed to

deploy properly. Investigation revealed that the apparent cause of one

of these failures has been attributed to the improper gluing method

used during the manufacturing process. The FAA finds this situation to

be isolated to a specific builder and limited to only seven units in

which only one unit failed.

However, further investigation has revealed that, during the

initial deployment stages of door 5 evacuation slide/raft, the

inflation bottle bag can apply adverse loads to both the forward side

bottle hanger strap and the lower girt attachment on the forward side

of this evacuation slide/raft. Such adverse loads could pull the center

girt attachment partially loose at the forward side, or could tear the

lower inflation tube assembly at the forward edge of the center girt.

The cause of such adverse loads has been attributed to the geometry of

this particular evacuation slide/raft. This condition, if not

corrected, could result in failure of door 5 evacuation slide/raft to

deploy properly, which could contribute to injury of passengers on the

slide, and could delay or impede the evacuation of passengers during an

emergency.

Explanation of Relevant Service Information

The FAA has reviewed and approved BFGoodrich Service Bulletin

7A1469-25-283, dated November 6, 1995, which describes procedures for

modification of door 5 evacuation slide/rafts. The modification

involves replacing the bottle support straps of door 5 with new support

straps, relocating these straps, and directly lacing them to the center

girt attachment. Accomplishment of the modification will eliminate

bonded attachments from the load path and prevent damage to the slide/

raft fabric.

Explanation of the Requirements of the Proposed Rule

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 modification of the door 5 evacuation slide/

rafts. The actions would be required to be accomplished in accordance

with the alert service bulletin described previously.

Explanation of the Applicability of the Proposed Rule

Operators should note that the applicability of this proposed rule

affects Boeing Model 747-400 series airplanes that are equipped with

certain BFGoodrich escape slide/rafts. The FAA's general policy is

that, when an unsafe condition results from the installation of an

appliance or other item that is installed in only one particular make

and model of aircraft, the AD is issued so that it is applicable to the

aircraft, rather than the item. The reason is simple: Making the AD

applicable to the airplane model on which the item is installed ensures

that operators of those airplanes will be notified directly of the

unsafe condition and the action required to correct it. While it is

assumed that an operator will know the models of airplanes that it

operates, there is a potential that the operator will not know or be

aware of specific items that are installed on its airplanes. It is for

this reason that this proposed AD would be applicable to Model 747-

400's rather than to the BFGoodrich escape slide/rafts. Additionally,

calling out the airplane model as the subject of the AD prevent

``unknowing non-compliance'' on the part of the operator.

The FAA recognizes that there are situations when an unsafe

condition exists in an item that is installed in many different

aircraft. In those cases, the FAA considers it impractical to issue

AD's against each aircraft; in fact, many times, the exact models and

number of aircraft on which the item is installed may not be known.

Therefore, in those situations, the AD is issued so that it is

applicable to the item; furthermore, those AD's usually indicate that

the item is known to be installed on, but not limited to, various

aircraft models.

Cost Impact

The FAA estimates that 150 BFGoodrich evacuation slide/rafts

installed on 75 Boeing Model 747-400

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series airplanes (2 slides per airplane) of U.S. registry would be

affected by this proposed AD, that it would take approximately 1 work

hour per slide to accomplish the proposed actions, and that the average

labor rate is $60 per work hour. Required parts would cost

approximately $84 per slide. Based on these figures, the cost impact of

the proposed AD on U.S. operators is estimated to be $21,600, or $144

per slide.

The 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.

Regulatory Impact

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 USC 106(g), 40113, 44701.

Sec. 39.13 [Amended]

2. Section 39.13 is amended by adding the following new

airworthiness directive:

Boeing: Docket 95-NM-218-AD.

Applicability: Model 747-400 series airplanes equipped with

BFGoodrich Evacuation Slide/Rafts at door 5; having slide/raft assembly

part number 7A1469-1, -2, -3, -4, -7, -8, -9, -10, -11, or -12 (all

unit serial numbers); certificated in any category.

Note 1: This AD applies to each airplane identified in the

preceding applicability provision, regardless of whether it has been

otherwise modified, altered, or repaired in the area subject to the

requirements of this AD. For airplanes that have been modified,

altered, or repaired so that the performance of the requirements of

this AD is affected, the owner/operator must request approval for an

alternative method of compliance in accordance with paragraph (b) of

this AD. The request should include an assessment of the effect of

the modification, alteration, or repair on the unsafe condition

addressed by this AD; and, if the unsafe condition has not been

eliminated, the request should include specific proposed actions to

address it.

Compliance: Required as indicated, unless accomplished

previously.

To prevent failure of the door 5 evacuation slide/raft to deploy

properly, which could contribute to injury of passengers on the

slide and could delay or impede the evacuation of passengers during

an emergency, accomplish the following:

(a) Within 36 months after the effective date of this AD, modify

the door 5 evacuation slide/raft in accordance with BFGoodrich

Service Bulletin 7A1469-25-283, dated November 6, 1995.

Note 2: Modification previous to the effective date of this AD

in accordance with Boeing Alert Service Bulletin 747-25A3096, which

references BFGoodrich Service Bulletin 7A1469-25-283, dated November

6, 1995, is considered acceptable for compliance with the

modification requirements of paragraph (a) of this AD.

(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 3: 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

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 April 23, 1996.

S.R. Miller,

Acting Manager, Transport Airplane Directorate, Aircraft Certification

Service.

[FR Doc. 96-10506 Filed 4-26-96; 8:45 am]

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