Airworthiness Directives; Boeing Model 767 Series Airplanes

DEPARTMENT OF TRANSPORTATION

14 CFR Part 39

[Docket No. 93-NM-228-AD; Amendment 39-8915; AD 94-10-08]

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

dye penetrant inspections and proof pressure testing to detect cracks

or ruptures of the crossover pneumatic duct, and repair or replacement,

as necessary. This amendment also requires stress relieving of the

crossover pneumatic duct assembly. This amendment is prompted by

reports of ruptured engine bleed air crossover ducts. The actions

specified by this AD are intended to prevent failure of the engine

bleed air crossover duct, which could result in loss of pneumatics and

damage to adjacent structure.

DATES: Effective June 17, 1994.

The incorporation by reference of certain publications listed in

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

of June 17, 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: Barbara Mudrovich, Aerospace Engineer,

Systems and Equipment Branch, ANM-130S; Seattle Aircraft Certification

Office, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone

(206) 227-2670; fax (206) 227-1181.

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

Aviation Regulations to include an airworthiness directive (AD) that is

applicable to Boeing Model 767 series airplanes was published in the

Federal Register on February 15, 1994 (59 FR 7231). That action,

applicable only to 14 specific airplanes, proposed to require dye

penetrant inspections and proof pressure testing to detect cracks or

ruptures of the crossover pneumatic duct; repair or replacement, as

necessary; and eventual stress relieving of the crossover pneumatic

duct assembly.

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 proposal.

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 14 Model 767 series airplanes of the

affected design in the worldwide fleet. The FAA estimates that 6

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

take approximately 18 work hours per airplane to accomplish the

required actions, and that the average labor rate is $55 per work hour.

Required parts will cost approximately $2,208 per airplane. Based on

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

estimated to be $19,188, or $3,198 per airplane.

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 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:

94-10-08 Boeing: Amendment 39-8915. Docket 93-NM-228-AD.

Applicability: Model 767 series airplanes; line position 308

through 321, inclusive; certificated in any category.

Compliance: Required as indicated, unless accomplished

previously.

Note 1: Inspections, testing, and repair or replacement

accomplished prior to the effective date of this amendment in

accordance with Boeing Alert Service Bulletin 767-36A0041, dated

July 2, 1992; or Revision 1, dated February 25, 1993; are considered

acceptable for compliance with the applicable action specified in

this amendment.

To prevent failure of the engine bleed air crossover duct, which

could result in loss of pneumatics and damage to adjacent structure,

accomplish the following:

(a) Option 1: As an alternative to the requirements of paragraph

(b) of this AD, accomplish the following:

(1) Within 6 months after the effective date of this AD, or

prior to the accumulation of 7,000 total flight cycles, whichever

occurs later, conduct a dye penetrant inspection and proof pressure

test of the crossover pneumatic duct, in accordance with Boeing

Service Bulletin 767-36A0041, Revision 2, dated October 28, 1993.

(i) If cracks or ruptures are detected, prior to further flight,

repair or replace the crossover pneumatic duct in accordance with

the service bulletin.

(ii) Stress relieving of the duct, in accordance with the

service bulletin, may be accomplished in conjunction with the

initial dye penetrant inspection and proof pressure test required by

this paragraph. Such action constitutes terminating action for the

requirements of paragraph (a)(2) of this AD.

(2) Within 3,000 flight cycles after accomplishing the initial

dye penetrant inspection and proof pressure test required by

paragraph (a)(1) of this AD, conduct an additional dye penetrant

inspection and proof pressure test of the crossover pneumatic duct,

and stress relieve the crossover pneumatic duct assembly, in

accordance with Boeing Service Bulletin 767-36A0041, Revision 2,

dated October 28, 1993. If cracks or ruptures are detected, prior to

further flight, repair or replace the crossover pneumatic duct in

accordance with the service bulletin.

(b) Option 2: As an alternative to the requirements of paragraph

(a) of this AD, accomplish the following:

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

prior to the accumulation of 7,000 total flight cycles, whichever

occurs later, conduct a dye penetrant inspection and proof pressure

test of the crossover pneumatic duct and stress relieve the

crossover pneumatic duct assembly, in accordance with Boeing Service

Bulletin 767-36A0041, Revision 2, dated October 28, 1993.

(2) If cracks or ruptures are detected, prior to further flight,

repair or replace the crossover pneumatic duct in accordance with

the service bulletin.

(c) Replacement of the crossover pneumatic duct with a stress

relieved duct in accordance with Boeing Service Bulletin 767-

36A0041, Revision 2, dated October 28, 1993, constitutes terminating

action for the requirements of paragraphs (a) and (b) of this AD.

(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 2: Information concerning the existence of approved

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

obtained from the Seattle ACO.

(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.

(f) The actions shall be done in accordance with Boeing Service

Bulletin 767-36A0041, Revision 2, dated October 28, 1993. 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.

(g) This amendment becomes effective on June 17, 1994.

Issued in Renton, Washington, on May 6, 1994.

S.R. Miller,

Acting Manager, Transport Airplane Directorate, Aircraft Certification

Service.

[FR Doc. 94-11524 Filed 5-17-94; 8:45 am]

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