AD 2001-11-07 Airworthiness Directives; Boeing Model 737, 757, and 767 Series Airplanes

Models named: 737, 757, 767 series. Read the applicability below — it usually turns on serial or part numbers too.

Model 737, 757, and 767 series airplanes, certificated in any category, as listed in the following Boeing Service Bulletins: Table 1.—Effectivity Boeing Service Bulletin Date Affected models/series 737-29A1073, Revision 3 December 2, 1999 Model 737-100, -200, -300, -400, and -500. 737-29A1081 December 2, 1999 Model 737-600, -700, and -800. 757-29A0048, Revision 3 December 2, 1999 Model 757-200. 757-29A0051 December 2, 1999 Model 757-300. 767-29A0083, Revision 4 September 28, 2000 Model 767. Note 1: Only motor operated hydraulic shutoff valves manufactured by Circle Seal Controls that are installed in the locations specified in the applicable alert service bulletin listed in the table above are subject to this AD. Note 2: 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 (c) 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.

Required as indicated, unless accomplished previously. To prevent failure of the motor operated hydraulic shutoff valves, which could result in leakage of hydraulic fluid to the engine fire zone, reduced ability to retract the landing gear, loss of backup electrical power or other combinations of failures, and consequent reduced controllability of the airplane, accomplish the following: Repetitive Operational Checks/Corrective Action (a) Within 6 months after the effective date of this AD: Perform an operational check to detect malfunctioning of any Circle Seal Controls motor operated hydraulic shutoff valve in a “sensitive system” application (as defined in the applicable service bulletin) having a part number specified in the “Existing Part Number” column (including parts marked with the suffix “R” after the serial number), of Paragraph 2.E. of Boeing Alert Service Bulletins 737-29A1073, Revision 3 (for Model 737-100, -200, -300, -400, and -500 series airplanes), 737-29A1081 (for Model 737-600, -700, and -800 series airplanes), 757-29A0048, Revision 3 (for Model 757-200 series airplanes), or 757-29A0051 (for Model 757-300 series airplanes); all dated December 2, 1999; or Boeing Service Bulletin 767-29A0083, Revision 4, dated September 28, 2000 (for Model 767 series airplanes); as applicable; in accordance with the applicable service bulletin. (1) If any malfunction of any valve is detected, prior to further flight, replace the valve with a new or serviceable Whittaker Controls or Circle Seal Controls valve in accordance with the applicable service bulletin. Repeat the operational check thereafter at intervals not to exceed 6 months until accomplishment of the terminating action required by paragraph (b) of this AD on all subject valves. (2) If no malfunction of any valve is detected, repeat the operational check thereafter at intervals not to exceed 6 months until accomplishment of the terminating action required by paragraph (b) of this AD on all subject valves. Note 3: Operational checks done before the effective date of this AD per Boeing Alert Service Bulletin 737-29A1073, Revision 2 (for Model 737 series airplanes), or 757-29A0048, Revision 2 (for Model 757 series airplanes), both dated July 1, 1999; or 767-29A0083, Revision 2, dated July 15, 1999 (for Model 767 series airplanes); as applicable; is acceptable for compliance with paragraph (a) of this AD. Terminating Action (b) Within 3 years after the effective date of this AD, accomplish the replacement of any Circle Seal Controls valve in a “sensitive system” application (as defined in the applicable service bulletin) having a P/N specified in the “Existing Part Number” column (including parts marked with the suffix “R” after the serial number), of Paragraph 2.E. of Boeing Alert Service Bulletin 737-29A1078 (for Model 737-100, -200, -300, -400, and -500 series airplanes), 737-29A1082 (for Model 737-600, -700, and -800 series airplanes), 757-29A0049 (for Model 757-200 series airplanes), 757-29A0052 (for Model 757-300 series airplanes), or 767-29A0090 (for Model 767 series airplanes); all dated December 7, 2000; as applicable. Replace an existing part with a new Whittaker Controls valve having a P/N specified in the “New Part Number” column of Paragraph 2.E. of the applicable service bulletin; or with a new Circle Seal Controls valve having P/N S270T010-10, -11, -12, -13, -14, or -15; as applicable. Do the replacement in accordance with the applicable alert service bulletin. Accomplishment of this replacement constitutes terminating action for the repetitive operational checks required by this AD. Note 4: Replacement of Circle Seal Controls valves done before the effective date of this AD per Boeing Alert Service Bulletin 737-29A1073, Revision 2 (for Model 737 series airplanes), or 757-29A0048, Revision 2 (for Model 757 series airplanes), both dated July 1, 1999; or 767-29A0083, Revision 2, dated July 15, 1999 (for Model 767 series airplanes); as applicable; is acceptable for compliance with paragraph (b) of this AD. Alternative Methods of Compliance (c) 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. 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 5: 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 (d) Special flight permits may be issued in accordance with §§ 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 (e) The actions shall be done in accordance with Boeing Alert Service Bulletin 737-29A1073, Revision 3, dated December 2, 1999; Boeing Alert Service Bulletin 737-29A1081, dated December 2, 1999: Boeing Alert Service Bulletin 757-29A0048, Revision 3, dated December 2, 1999; Boeing Alert Service Bulletin 757-29A0051, dated December 2, 1999; Boeing Service Bulletin 767-29A0083, Revision 4, dated September 28, 2000; Boeing Alert Service Bulletin 737-29A1078, dated December 7, 2000; Boeing Alert Service Bulletin 737-29A1082, dated December 7, 2000; Boeing Alert Service Bulletin 757-29A0049, dated December 7, 2000; Boeing Alert Service Bulletin 757-29A0052, dated December 7, 2000; or Boeing Alert Service Bulletin 767-29A0090, dated December 7, 2000; 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. Effective Date (f) This amendment becomes effective on July 16, 2001. Issued in Renton, Washington, on May 25, 2001. Vi L. Lipski, Manager, Transport Airplane Directorate,Aircraft Certification Service. [FR Doc. 01-14000 Filed 6-8-01; 8:45 am] BILLING CODE 4910-13-U