Airworthiness Directive · Amendment 39-11962 · Boeing Model 747-100, -200B, -200C, -200F, and -300 Series Airplanes Delivered In or Modified Into the Stretched Upper Deck Configuration
Boeing Model 747-100, -200B, -200C, -200F, and -300 Series Airplanes Delivered In or Modified Into the Stretched Upper Deck Configuration
Model 747-100, -200B, -200C, -200F, and -300 series airplanes; certificated in any category; equipped with Pratt & Whitney Model JT9D-3 or -7 series engines, General Electric Model CF6-45 or -50 series engines, or Rolls-Royce Model RB211-524B, C, or D series engines; delivered in or modified into the stretched upper deck (SUD) configuration; and having angle assemblies with Boeing part numbers 015U0454-63 and 015U0454-64 installed at body station 970.
Note 1: Model 747-100 SUD series airplanes on which paragraph (g) of AD 2000-05-30 has been accomplished are not required to comply with this AD.
Note 2: This AD applies to each airplane identified in the preceding applicability provision, regardless of whether it has been otherwise 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 (b) 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.
This amendment adopts a new airworthiness directive (AD) that is applicable to certain Boeing Model 747-100, -200B, -200C, -200F, and -300 series airplanes delivered in or modified into the stretched upper deck configuration. This action requires a one-time inspection to detect chafing between certain engine thrust control cables and certain cable penetration holes, and follow-on actions, if necessary. This action is necessary to prevent chafing and failure of engine thrust control cables, which could result in a severe asymmetric thrust condition during landing, and consequent reduced controllability of the airplane. This action is intended to address the identified unsafe condition.
To prevent chafing and failure of engine thrust control cables, which could result in a severe asymmetric thrust condition during landing, and consequent reduced controllability of the airplane, accomplish the following:
(a) Within 18 months after the effective date of this AD, perform a detailed visual inspection and measure the clearance between the engine thrust control cables and the cable penetration holes, in accordance with the Cable Chafing Inspection of the Accomplishment Instructions of Boeing Service Bulletin 747-53-2327, Revision 2, dated September 24, 1998. If insufficient clearance exists, as specified in the service bulletin, prior to further flight, accomplish paragraphs (a)(1) and (a)(2) of this AD.
(1) Modify the cable penetration holes or replace the plate, as applicable, in accordance with Figure 7 of the service bulletin.
(2) Perform a detailed visual inspection of the engine thrust control cables in the area of the plate to detect wear and broken wires in accordance with Appendix 1 (including Figure 1) of this AD. If any wear is within the criteria contained in Appendix 1 (including Figure 1) of this AD, no further action is required by this paragraph. If any wear outside the criteria contained in Appendix 1 (including Figure 1) of this AD is found, prior to further flight, replace the cable with a new cable, in accordance with the procedures described in the Boeing 747 Maintenance Manual.
Note 3: 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.”
