AD 94-10-08 ACTIVE

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.

Final rule

94-10-08 BOEING: Amendment 39-8915. Docket 93-NM-228-AD. \n\n\tApplicability: Model 767 series airplanes; line position 308 through 321, inclusive; certificated in any category. \n\n\tCompliance: Required as indicated, unless accomplished previously. \n\nNOTE 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. \n\n\tTo prevent failure of the engine bleed air crossover duct, which could result in loss of pneumatics and damage to adjacent structure, accomplish the following: \n\n\t(a)\tOPTION 1: As an alternative to the requirements of paragraph (b) of this AD, accomplish the following: \n\n\t\t(1)\tWithin 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. \n\n\t\t\t(i)\tIf cracks or ruptures are detected, prior to further flight, repair or replace the crossover pneumatic duct in accordance with the service bulletin. \n\n\t\t\t(ii)\tStress 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. \n\n\t\t(2)\tWithin 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. \n\n\t(b)\tOPTION 2: As an alternative to the requirements of paragraph (a) of this AD, accomplish the following: \n\n\t\t(1)\tWithin 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. \n\n\t\t(2)\tIf cracks or ruptures are detected, prior to further flight, repair or replace the crossover pneumatic duct in accordance with the service bulletin. \n\n\t(c)\tReplacement 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. \n\n\t(d)\tAn 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. \n\nNOTE 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Seattle ACO. \n\n\t(e)\tSpecial 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.\n \n\t(f)\tThe 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. \n\n\t(g)\tThis amendment becomes effective on June 17, 1994.

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. \n\n\tInterested persons have been afforded an opportunity to participate in the making of this amendment. Due consideration has been given to the two comments received. \n\n\tBoth commenters support the proposal. \n\n\tAfter 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. \n\n\tThere 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. \n\n\tThe 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. \n\n\tThe 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. \n\n\tFor 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." \n\nList of Subjects in 14 CFR Part 39 \n\nAir transportation, Aircraft, Aviation safety, Incorporation by reference, Safety. \n\nAdoption of the Amendment \n\nAccordingly, 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: \n\nPART 39 - AIRWORTHINESS DIRECTIVES \n\n1.\tThe 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. § 39.13 - (Amended) \n \n2.\tSection 39.13 is amended by adding the following new airworthiness directive:

The service information referenced in this AD may be obtained from Boeing\nCommercial 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.

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.