Airworthiness Directives; Boeing Model 757-200 and -200PF Series Airplanes

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-NM-57-AD]

RIN 2120-AA64

Airworthiness Directives; Boeing Model 757-200 and -200PF Series

Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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

SUMMARY: This document proposes the adoption of a new airworthiness

directive (AD) that is applicable to certain Boeing Model 757-200 and -

200PF series airplanes. This proposal would require repetitive detailed

visual inspections to detect loose fuse pins in the outboard beam

attachment and forward trunnion support on the main landing gear (MLG)

and to detect corrosion on the structure adjacent to the fuse pin; and

corrective actions, if necessary. This proposal also would require

eventual replacement of the fuse pins with new corrosion resistant

steel (CRES) fuse pins, which would constitute terminating action for

the repetitive inspections. This proposal is prompted by a report of

damaged fuse pins caused by corrosion. The actions specified by the

proposed AD are intended to prevent corroded fuse pins, which could

result in the MLG separating from the wing, and consequent damage to

the airplane and possible rupture of the wing fuel tank.

DATES: Comments must be received by November 22, 1999.

ADDRESSES: Submit comments in triplicate to the Federal Aviation

Administration (FAA), Transport Airplane Directorate, ANM-114,

Attention: Rules Docket No. 99-NM-57-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 Boeing Commercial Airplane Group, P.O. Box 3707, Seattle,

Washington 98124-2207. This information may be examined at the FAA,

Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton,

Washington.

FOR FURTHER INFORMATION CONTACT: Rick Kawaguchi, Aerospace Engineer,

Airframe Branch, ANM-120S, FAA, Transport Airplane Directorate, Seattle

Aircraft Certification Office, 1601 Lind Avenue, SW., Renton,

Washington 98055-4056; telephone (425) 227-1153; fax (425) 227-1181.

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 99-NM-57-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-114, Attention: Rules

Docket No. 99-NM-57-AD, 1601 Lind Avenue, SW., Renton, Washington

98055-4056.

Discussion

The FAA has received a report indicating that, during heavy

maintenance of several Boeing Model 757-200 series airplanes, 28 fuse

pins were found damaged due to corrosion. Fuse pins made from 4330M and

4340 alloy with cracks in the chrome plating can be damaged by

corrosion. Such corrosion or cracking, if not corrected, could result

in the main landing gear (MLG) separating from the wing, and consequent

damage to the airplane and possible rupture of the wing fuel tank.

The subject fuse pins on Boeing Model 757-200PF series airplanes

are identical to those on the affected Boeing Model 757-200 series

airplanes. Therefore, both of these airplanes may be subjected to the

same unsafe condition.

Explanation of Relevant Service Information

The FAA has reviewed and approved Boeing Alert Service Bulletin

757-57A0054, dated November 5, 1998, which describes procedures for

repetitive detailed visual inspections to detect loose fuse pins in the

outboard beam attachment and forward trunnion support on the MLG and

corrosion on the structure adjacent to the fuse pin; and corrective

actions, if necessary. The corrective actions involve performing a

detailed visual inspection to detect corrosion on the fuse pin's mating

parts, and repairing the parts, if necessary; performing a detailed

visual inspection to detect cracks on the outer surface of the fuse pin

chrome plating; and replacing the alloy steel fuse pins with new

corrosion resistant steel (CRES) fuse pins, which would eliminate the

need for the repetitive inspections. The service bulletin also

describes procedures for a terminating action for the repetitive

inspections. Accomplishment of the action specified in the service

bulletin is intended to adequately address the identified unsafe

condition.

Explanation of Requirements of 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 accomplishment of the actions

[[Page 54228]]

specified in the service bulletin described previously.

Cost Impact

There are approximately 805 airplanes of the affected design in the

worldwide fleet. The FAA estimates that 350 airplanes of U.S. registry

would be affected by this proposed AD.

It would take approximately 1 work hour per airplane to accomplish

the proposed inspection, at an average labor rate of $60 per work hour.

Based on these figures, the cost impact of the inspection proposed by

this AD on U.S. operators is estimated to be $21,000, or $60 per

airplane, per inspection cycle.

It would take approximately 440 work hours per airplane to

accomplish the proposed replacement, at an average labor rate of $60

per work hour. The manufacturer has committed previously to its

customers that it will bear the cost of replacement parts. As a result,

the cost of those parts are not attributable to this proposed AD. Based

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

is estimated to be $9,240,000, or $26,400 per airplane.

The cost impact figures discussed above are 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 U.S.C. 106(g), 40113, 44701.

Sec. 39.13 [Amended]

2. Section 39.13 is amended by adding the following new

airworthiness directive:

Boeing: Docket 99-NM-57-AD.

Applicability: Model 757-200 and -200PF series airplanes, line

numbers 1 through 806 inclusive; certificated in any category.

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

preceding applicability provision, regardless of whether it has been

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 (d) 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 corroded fuse pins, which could result in the main

landing gear (MLG) separating from the wing, and consequent damage

to the airplane and possible rupture of the wing fuel tank,

accomplish the following:

Repetitive Inspections

(a) Perform a detailed visual inspection to detect loose fuse

pins in the outboard beam attachment and forward trunnion support on

the MLG and to detect corrosion on the structure adjacent to the

fuse pin, in accordance with Boeing Alert Service Bulletin 757-

57A0054, dated November 5, 1998; at the later of the times specified

in paragraphs (a)(1) and (a)(2) of this AD. Thereafter, repeat the

inspection at intervals not to exceed 3,000 flight cycles or 24

months, whichever occurs first, until accomplishment of paragraph

(c) of this AD.

(1) Prior to 4 years since date of manufacture of the airplane;

or

(2) Within 3,000 flight cycles or 24 months after the effective

date of this AD, whichever occurs first.

Note 2: For the purposes of this AD, a detailed visual

inspection is defined as: ``An intensive visual examination of a

specific structural area, system, installation, or assembly to

detect damage, failure, or irregularity. Available lighting is

normally supplemented with a direct source of good lighting at

intensity deemed appropriate by the inspector. Inspection aids such

as mirror, magnifying lenses, etc., may be used. Surface cleaning

and elaborate access procedures may be required.''

Corrective Action

(b) If any loose fuse pin or corrosion on the structure adjacent

to the fuse pin is detected during any inspection required by

paragraph (a) of this AD, prior to further flight, perform the

applicable corrective action [i.e., detailed visual inspections for

cracks or corrosion, repair of discrepant parts, and replacement of

fuse pin] in accordance with Boeing Alert Service Bulletin 757-

57A0054, dated November 5, 1998. Replacement of an alloy steel fuse

pin with a new corrosion resistant steel (CRES) fuse pin constitutes

terminating action for the repetitive inspection requirements of

paragraph (a) of this AD for that fuse pin only.

Terminating Action

(c) At the next scheduled MLG overhaul, or within 12 years after

the effective date of this AD, whichever occurs first, replace all

alloy steel fuse pins with new CRES fuse pins in the outboard beam

attachment and forward trunnion support on the MLG in accordance

with Boeing Alert Service Bulletin 757-57A0054, dated November 5,

1998. Accomplishment of the action specified in this paragraph

constitutes terminating action for the repetitive inspection

requirements of this AD.

Alternative Methods of Compliance

(d) 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, Seattle 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, Seattle ACO.

Note 3: Information concerning the existence of approved

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

obtained from the Seattle ACO.

Special Flight Permits

(e) 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 September 29, 1999.

D.L. Riggin,

Acting Manager, Transport Airplane Directorate, Aircraft Certification

Service.

[FR Doc. 99-25936 Filed 10-5-99; 8:45 am]

BILLING CODE 4910-13-U