Airworthiness Directive · Amendment 39-13996 · Boeing Model 747-100, -100B, -100B SUD, -200B, -200C, -200F, and -300 Series Airplanes; and Model 747SP and 747SR Series Airplanes; Equipped With Pratt and Whitney Model JT9D-3 or -7 (Except -70) Series Engines
Boeing Model 747-100, -100B, -100B SUD, -200B, -200C, -200F, and -300 Series Airplanes; and Model 747SP and 747SR Series Airplanes; Equipped With Pratt and Whitney Model JT9D-3 or -7 (Except -70) Series Engines
This AD applies to Boeing Model 747-100, -100B, -100B SUD, -200B, -200C, -200F, and -300 series airplanes; and Model 747SP and 747SR series airplanes; equipped with Pratt and Whitney Model JT9D-3, or -7 (except for -70) series engines; as identified in Boeing Alert Service Bulletin 747-54A2220, dated July 31, 2003; certificated in any category.
The FAA is adopting a new airworthiness directive (AD) for certain Boeing transport category airplanes. This AD requires repetitive detailed inspections to detect cracking of the aft and forward surfaces of the bulkhead web at nacelle station 180, and repair if necessary. This AD is prompted by reports of cracking of the web bulkhead at nacelle station 180. We are issuing this AD to detect and correct fatigue cracking of the web bulkhead, and consequent loss of the load path of the bulkhead at nacelle station 180, which when combined with the loss of the midspar load path, could result in the in-flight separation of the engine and strut. Such separation may result in secondary damage to the airplane and consequent reduced controllability of the airplane.
You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done.
Within 9 months after the effective date of this AD, do a detailed inspection to detect cracking of the aft and forward surfaces of the bulkhead web at nacelle station 180, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 747-54A2220, dated July 31, 2003.
(1) If no cracking is detected, repeat the detailed inspection at the applicable intervals specified in the “Repeat Inspection Interval” column of Tables 1 and 2 in Figure 1 of the service bulletin.
(2) If any cracking is detected, before further flight, repair the cracking in accordance with the service bulletin, except as provided by paragraph (f)(3) of this AD. Thereafter, repeat the detailed inspection at the applicable intervals specified in the “Repeat Inspection Interval” column of Tables 1 and 2 in Figure 1 of the service bulletin.
(3) If any cracking exceeds the repair limits specified in the applicable structural repair manual (referenced in the service bulletin), before further flight, repair the cracking in accordance with a method approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA; or in accordance with data meeting the certification basis of the airplane approved by an Authorized Representative (AR) for the Boeing Delegation Option Authorization (DOA) Organization who has been authorized by the Manager, Seattle ACO, to make those findings. For a repair method to be approved, the repair must meet the certification basis of the airplane, and the approval must specifically refer to this AD.
