Airworthiness Directives; Boeing Model 767 Series Airplanes Equipped With General Electric CF6-80A or Pratt and Whitney JT9D-7R4 Engines

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 94-NM-13-AD; Amendment 39-8953; AD 94-14-01]

Airworthiness Directives; Boeing Model 767 Series Airplanes

Equipped With General Electric CF6-80A or Pratt and Whitney JT9D-7R4

Engines

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

replacement of the thrust reverser flow restrictor devices with one-way

(check) valve restrictors. This amendment is prompted by reports of

piston seal leakage found during actuator overhaul on certain Model 767

series airplanes. The actions specified by this AD are intended to

prevent possible deployment of a thrust reverser in flight and

subsequent reduced controllability of the airplane.

DATES: Effective August 1, 1994.

The incorporation by reference of certain publications listed in

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

of August 1, 1994.

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: Richard Simonson, Aerospace Engineer,

Propulsion Branch, ANM-140S, FAA, Transport Airplane Directorate,

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

Washington 98055-4056; telephone (206) 227-2683; fax (206) 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 in the Federal Register on March 16, 1994 (59

FR 12207). That action proposed to require replacement of the thrust

reverser flow restrictor devices with one-way (check) valve

restrictors.

Interested persons have been afforded an opportunity to participate

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

the two comments received.

Both commenters support the proposed rule.

After careful review of the available data, including the comments

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

interest require the adoption of the rule as proposed.

There are approximately 119 Model 767 series airplanes equipped

with General Electric CF6-80A engines of the affected design in the

worldwide fleet. The FAA estimates that 69 airplanes of U.S. registry

will be affected by this AD, that it will take approximately 32 work

hours per airplane to accomplish the required actions, and that the

average labor rate is $55 per work hour. Required parts will be

supplied by the manufacturer at no cost to operators. Based on these

figures, the total cost impact of the AD on U.S. operators of Model 767

series airplanes equipped with General Electric CF6-80A engines is

estimated to be $121,440, or $1,760 per airplane.

There are approximately 95 Model 767 series airplanes equipped with

Pratt & Whitney JT9D-7R4 engines of the affected design in the

worldwide fleet. The FAA estimates that 30 airplanes of U.S. registry

will be affected by this AD, that it will take approximately 30 work

hours per airplane to accomplish the required actions, and that the

average labor rate is $55 per work hour. Required parts will be

supplied by the manufacturer at no cost to operators. Based on these

figures, the total cost impact of the AD on U.S. operators of Model 767

series airplanes equipped with Pratt & Whitney JT9D-7R4 engines is

estimated to be $49,500, or $1,650 per airplane.

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

operators is estimated to be $170,940.

The total cost impact figure discussed above is 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.

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. 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: 94-14-01 BOEING: Amendment 39-8953. Docket 94-

NM-13-AD.

Applicability: Model 767 series airplanes equipped with General

Electric CF6-80A or Pratt & Whitney JT9D-7R4 engines, certificated

in any category.

Compliance: Required as indicated, unless accomplished

previously. -

To prevent possible deployment of a thrust reverser in flight

and subsequent reduced controllability of the airplane, accomplish

the following:

(a) Within 18 months after the effective date of this AD,

replace the thrust reverser flow restrictor devices with one-way

(check) valve restrictors in accordance with Boeing Alert Service

Bulletin 767-78-0064 (for Model 767 series airplanes equipped with

General Electric CF6-80A engines) or 767-78-0065 (for Model 767

series airplanes equipped with Pratt & Whitney JT9D-7R4 engines),

both dated July 16, 1992, as applicable.

(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, 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: Information concerning the existence of approved

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

obtained from the Seattle 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.

(d) The replacement shall be done in accordance with Boeing

Alert Service Bulletin 767-78-0064, dated July 16, 1992, or Boeing

Alert Service Bulletin 767-78-0065, dated July 16, 1992, as

applicable. 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.

(e) This amendment becomes effective on August 1, 1994.

Issued in Renton, Washington, on June 21, 1994.

Darrell M. Pederson,

Acting Manager, Transport Airplane Directorate, Aircraft Certification

Service.

[FR Doc. 94-15474 Filed 6-29-94; 8:45 am]

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