Airworthiness Directives; Boeing Model 767 Series Airplanes

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 97-NM-186-AD; Amendment 39-11468; AD 99-26-09]

RIN 2120-AA64

Airworthiness Directives; Boeing Model 767 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment adopts a new airworthiness directive (AD),

applicable to certain Boeing Model 767 series airplanes, that requires

repetitive inspections to ensure the proper condition of the engine

thrust link components, and follow-on corrective action, if necessary;

and replacement of the end cap assembly with an improved assembly. Such

replacement, when accomplished, terminates the repetitive inspections.

This amendment is prompted by a report of fatigue cracking of end cap

bolts caused by improper installation. The actions specified by this AD

are intended to prevent failure of the end cap assembly, which could

lead to separation of the engine from the airplane in the event of a

primary thrust linkage failure.

DATES: Effective January 24, 2000.

The incorporation by reference of certain publications listed in

the regulations is approved by the Director of the Federal Register as

of January 24, 2000.

ADDRESSES: The service information referenced in this AD may be

obtained from Boeing Commercial Airplane Group, P.O. Box 3707, Seattle,

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

Aviation Administration (FAA), Transport Airplane Directorate, Rules

Docket, 1601 Lind Avenue, SW., Renton, Washington; or at the Office of

the Federal Register, 800 North Capitol Street, NW., suite 700,

Washington, DC.

FOR FURTHER INFORMATION CONTACT: James G. Rehrl, Aerospace Engineer,

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

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

Washington 98055-4056; telephone (425) 227-2783; fax (425) 227-1181.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal

Aviation Regulations (14 CFR part 39) to include an airworthiness

directive (AD) that is applicable to certain Boeing Model 767 series

airplanes was published as a supplemental notice of proposed rulemaking

(NPRM) in the Federal Register on October 21, 1999 (64 FR 56709). That

action proposed to require repetitive inspections to ensure the proper

condition of the engine thrust link components, and follow-on

corrective action, if necessary; and replacement of the end cap

assembly with an improved assembly. Such replacement, when

accomplished, terminates the repetitive inspections. That action also

revises the proposed rule by adding a repair requirement and by

clarifying the type of inspection and terminology used in describing

the parts to be inspected.

Comments

Interested persons have been afforded an opportunity to participate

in the making of this amendment. Due consideration has been given to

the single comment received.

The Air Transport Association of America (ATA), on behalf of its

members, supports the proposed rule. The ATA states that responding

members indicated that they had no comment or no objection to the

proposed rule.

Conclusion

After careful review of the available data, including the comment

noted above, the FAA has determined that air safety and the public

interest require the adoption of the rule as proposed.

Cost Impact

There are approximately 239 Model 767 series airplanes of the

affected design in the worldwide fleet. The FAA estimates that 96

airplanes of U.S. registry will be affected by this AD, that it will

take approximately 37 work hours per airplane (18.5 work hours per

engine) to accomplish the required inspections, and that the average

labor rate is $60 per work hour. Based on these figures, the cost

impact of this AD on U.S. operators is estimated to be $213,120, or

$2,220 per airplane, per inspection cycle.

It will take approximately 135 work hours per airplane (67.5 work

hours per engine) to accomplish the required replacement of the forward

engine mount end cap and bolts, at an average labor rate of $60 per

work hour. Required parts will cost approximately $1,000 per airplane.

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

estimated to be $873,600, or $9,100 per airplane.

The cost impact figures discussed above are based on assumptions

that no operator has yet accomplished any of the 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 adopted herein will 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 final

rule does not have sufficient federalism implications to warrant the

preparation of a Federalism Assessment.

For the reasons discussed above, I certify that this action (1) is

not a ``significant regulatory action'' under Executive Order 12866;

(2) is not a ``significant rule'' under DOT Regulatory Policies and

Procedures (44 FR 11034, February 26, 1979); and (3) 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 final evaluation has been prepared for this action

and it is contained in the Rules Docket. A copy of it may be obtained

from the Rules Docket at the location provided under the caption

ADDRESSES.

List of Subjects in 14 CFR Part 39

Air transportation, Aircraft, Aviation safety, Incorporation by

reference, Safety.

Adoption of the Amendment

Accordingly, pursuant to the authority delegated to me by the

Administrator, the Federal Aviation Administration amends 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:

99-26-09 Boeing: Amendment 39-11468. Docket 97-NM-186-AD.

Applicability: Model 767 series airplanes, powered by Pratt &

Whitney Model JT9D or Model PW4000 series engines, as listed in

Boeing Alert Service Bulletin 767-71A0087, dated October 10, 1996;

certificated in any category.

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

preceding applicability provision, regardless of whether it has been

[[Page 71007]]

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 (e) 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 possible separation of the engine from the airplane

in the event of a primary thrust linkage failure, accomplish the

following:

Initial and Repetitive Inspections

(a) For Groups 1 and 2 airplanes: Accomplish paragraphs (a)(1),

(a)(2), and (a)(3) of this AD, as applicable, in accordance with

Boeing Alert Service Bulletin 767-71A0087, dated October 10, 1996.

(1) Within 500 flight hours or 300 flight cycles after the

effective date of this AD, whichever occurs later: Accomplish Work

Package 1 (a detailed visual inspection of the forward engine mount

to ensure that the thrust link, evener bar, associated lugs, and

attaching hardware are firmly attached). Thereafter, repeat Work

Package 1 at the intervals specified in the alert service bulletin

until the requirements of either paragraph (a)(2) or (a)(3) of this

AD are accomplished.

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 an

intensity deemed appropriate by the inspector. Inspection aids such

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

and elaborate access procedures may be required.''

(2) Prior to the accumulation of 16,000 total flight cycles on

any engine or within 500 flight hours or 300 flight cycles after the

effective date of this AD, whichever occurs later: Accomplish Work

Package 2 (non-destructive test inspection of the forward engine

mount to ensure the proper condition of the engine thrust link

components). Thereafter, repeat Work Package 2 on that engine at the

intervals specified in the alert service bulletin until the

requirements of paragraph (a)(3) of this AD are accomplished.

Accomplishment of Work Package 2 constitutes terminating action for

the repetitive inspections required by paragraph (a)(1) of this AD

for that engine.

Replacement and Terminating Action

(3) Within 3 years after the effective date of this AD:

Accomplish Work Package 3 (end cap and bolt replacement of the

forward engine mount). Accomplishment of Work Package 3 constitutes

terminating action for the requirements of this AD for Groups 1 and

2 airplanes.

(b) For Group 3 airplanes: Within 3 years after the effective

date of this AD, accomplish Work Package 4 (bolt replacement) in

accordance with Boeing Alert Service Bulletin 767-71A0087, dated

October 10, 1996.

Repair and Replacement Action

(c) For all airplanes: If any discrepancy (including an

improperly installed or damaged engine thrust link component) is

found during any inspection required by this AD, prior to further

flight, accomplish the actions required by paragraphs (c)(1) and

(c)(2) of this AD.

(1) Repair any discrepancies in accordance with a method

approved by the Manager, Seattle Aircraft Certification Office

(ACO), FAA, Transport Airplane Directorate. For a repair method to

be approved by the Manager, Seattle ACO, as required by this

paragraph, the Manager's approval letter must specifically reference

this AD.

(2) Accomplish Work Package 3 in accordance with Boeing Alert

Service Bulletin 767-71A0087, dated October 10, 1996.

Spares

(d) As of the effective date of this AD, no person shall install

a forward engine mount end cap having part number 310T3026-1 on any

airplane.

Alternative Method of Compliance

(e) 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 ACO. 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

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

Secs. 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.

Incorporation by Reference

(g) Except as provided by paragraph (c)(1) of this AD, the

actions shall be done in accordance with Boeing Alert Service

Bulletin 767-71A0087, dated October 10, 1996. This incorporation by

reference was approved by the Director of the Federal Register in

accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be

obtained from Boeing Commercial Airplane Group, P.O. Box 3707,

Seattle, Washington 98124-2207. Copies may be inspected at the FAA,

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

Washington; or at the Office of the Federal Register, 800 North

Capitol Street, NW., suite 700, Washington, DC.

(h) This amendment becomes effective on January 24, 2000.

Issued in Renton, Washington, on December 9, 1999.

D.L. Riggin,

Acting Manager, Transport Airplane Directorate, Aircraft Certification

Service.

[FR Doc. 99-32507 Filed 12-17-99; 8:45 am]

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