AD 2001-13-12 Airworthiness Directives; Boeing Model 747 Series Airplanes

Models named: 747 series. Read the applicability below — it usually turns on serial or part numbers too.

Model 747 series airplanes, as listed in Boeing Service Bulletin 747-57A2310, Revision 2, dated February 22, 2001; certificated in any category. Note 1: 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 (g) 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 detect and correct cracking on the actuator attach fittings of the trailing edge flaps, which could result in abnormal operation or retraction of a trailing edge flap, and consequent reduced controllability of the airplane, accomplish the following: Actuator Attach Fittings That Have Not Been Overhauled or Replaced (a) For actuator attach fittings on the outboard flaps that have NOT been overhauled in accordance with revisions of Boeing 747 Overhaul Manual (OHM) 57-52-55 dated prior to June 1, 1999, or replaced with a new fitting, prior to the effective date of this AD; and for actuator attach fittings on the inboard flap actuators that have NOT been overhauled in accordance with revisions of OHM 57-52-35, dated prior to June 1, 1999, or replaced with a new fitting, prior to the effective date of this AD: Accomplish the actions in paragraph (c), (d), or (e) of this AD at the later of the times specified in paragraphs (a)(1) and (a)(2) of this AD. (1) Prior to the accumulation of 8 years since date of manufacture or 8,000 total flight cycles, whichever occurs first. (2) Within 6 months after the effective date of this AD. Actuator Attach Fittings That Have Been Overhauled or Replaced (b) For actuator attach fittings on the outboard flaps that HAVE been overhauled in accordance with revisions of OHM 57-52-55 dated prior to June 1, 1999, or replaced with a new fitting, prior to the effective date of this AD; and for actuator attach fittings on the inboard flap actuators that HAVE been overhauled in accordance with revisions of OHM 57-52-35 dated prior to June 1, 1999, or replaced with a new fitting, prior to the effective date of this AD: Accomplish the actions in paragraph (c), (d), or (e) of this AD at the later of the times specified in paragraphs (b)(1) and (b)(2) of this AD. (1) Within 8 years or 8,000 total flight cycles after the attach fitting was overhauled or replaced, whichever occurs first. (2) Within 6 months after the effective date of this AD. Inspections and Corrective Action (c) Perform a detailed visual inspection to detect corrosion around the lower bearing journal on the actuator attach fittings on the inboard and outboard flaps, and perform an ultrasonic inspection to detect cracks around the lower bearing journal of the actuator attach fittings on the outboard flaps, in accordance with Boeing Service Bulletin 747-57A2310, Revision 1, dated November 23, 1999; or Revision 2, dated February 22, 2001. 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 intensity deemed appropriate by the inspector. Inspection aids such as mirror, magnifying lenses, etc., may be used. Surface cleaning and elaborate access procedures may be required.” Note 3: Inspections and replacements accomplished in accordance with Boeing Alert Service Bulletin 747-57A2310, dated June 17, 1999, are acceptable for compliance with the requirements of paragraph (c) of this AD. (1) If no corrosion or cracks are detected, repeat the inspections required by paragraph (c) of this AD at intervals not to exceed 18 months. Within 5 years after the initial inspections required by paragraph (c) of this AD, accomplish the actions specified in paragraph (d) or (e) of this AD. (2) If any corrosion is detected, prior to further flight, remove the corrosion by accomplishing the actions of either paragraph (c)(2)(i) or (c)(2)(ii) of this AD. (i) If corrosion is within the limits of the Boeing 747 OHM: Prior to further flight, accomplish the actions specified in paragraph (d) or (e) of this AD. (ii) If corrosion is not within the limits of the Boeing 747 OHM: Prior to further flight, accomplish the actions specified in paragraph (e) or (f) of this AD. (3) If any crack is detected: Prior to further flight, accomplish the actions specified in paragraph (e) or (f) of this AD. Overhaul (d) Overhaul the actuator attach fittings on the outboard flaps in accordance with the Accomplishment Instructions of Boeing Service Bulletin 747-57A2310, Revision 1, dated November 23, 1999; or Revision 2, dated February 22, 2001. Repeat the overhaul of actuators on the outboard flaps as specified in Part 2 of the Work Instructions of the service bulletin thereafter at intervals not to exceed 8 years or 8,000 flight cycles, whichever occurs first. Accomplishment of the overhaul of the actuator attach fittings on the outboard flaps constitutes terminating action for the repetitive inspection requirements of paragraph (c)(1) of this AD. Overhaul the actuator attach fittings on the inboard flaps in accordance with the Accomplishment Instructions of Boeing Service Bulletin 747-57A2310, Revision 1, dated November 23, 1999; or Revision 2, dated February 22, 2001. Accomplishment of the overhaul of the actuator attach fittings on the inboard flaps constitutes terminating action for the requirements of this AD for the actuator attach fittings on the inboard flaps. Replacement (e) Replace the actuator attach fittings on the inboard and outboard flaps in accordance with paragraph (e)(1) or (e)(2) of this AD. (1) Replace the actuator attach fittings on the inboard and outboard flaps with new attach fittings in accordance with “Part 3—Replacement” of Boeing Service Bulletin 747-57A2310, Revision 1, dated November 23, 1999; or Revision 2, dated February 22, 2001. Accomplishment of this replacement constitutes terminating action for the repetitive inspections required by paragraph (c) of this AD for the replaced fitting. Within 8 years or 8,000 flight cycles following accomplishment of the replacement, whichever occurs first, repeat this replacement or accomplish the overhaul specified in paragraph (d) of this AD. (2) Replace the actuator attach fittings on the inboard and outboard flaps with improved attach fittings in accordance with “Part 4—Terminating Action” of Boeing Service Bulletin 747-57A2310, Revision 2, dated February 22, 2001. If accomplished, this replacement with improved fittings terminates the requirements of this AD for the replaced fitting. Note 4: Replacement of the actuator attach fittings on the inboard flaps with fittings that have been overhauled in accordance with Boeing OHM 57-52-35, Temporary Revision 57-8, dated June 10, 1999; Temporary Revision 57-10, dated May 8, 2000; or Full Revision 57-10, dated July 1, 2000; constitutes terminating action for the requirements of this AD for the actuator attach fittings on the inboard flaps. Repair (f) During any inspection done in accordance with paragraph (c) of this AD, if corrosion is found that is outside the limits specified in the Boeing 747 OHM, or if any crack is detected: In lieu of replacement of the actuator attach fittings in accordance with paragraph (e) of this AD, repair the actuator attach fittings on the inboard and outboard flaps in accordance with a method approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA; or per data meeting the type certification basis of the airplane approved by a Boeing Company Designated Engineering Representative who has been authorized by the Manager, Seattle ACO, to make such findings. 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. Alternative Methods of Compliance (g) 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 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 (h) 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. Incorporation by Reference (i) Except as provided by paragraph (f) of this AD, the actions shall be done in accordance with Boeing Service Bulletin 747-57A2310, Revision 1, dated November 23, 1999; or Boeing Service Bulletin 747-57A2310, Revision 2, dated February 22, 2001; 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 (j) This amendment becomes effective on August 3, 2001. Issued in Renton, Washington, on June 20, 2001. Kalene C. Yanamura, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. 01-16049 Filed 6-28-01; 8:45 am] BILLING CODE 4910-13-P