Airworthiness Directive · Amendment 39-18783 · Nacelles/pylons
The Boeing Company Airplanes
This AD applies to The Boeing Company Model 747-200B, 747-300, 747-400, 747-400D, and 747-400F series airplanes, certificated in any category, equipped with General Electric (GE) CF6-80 series engines or Pratt & Whitney PW4000 series engines; as identified in Boeing Alert Service Bulletin 747-54A2245, Revision 1, dated September 20, 2016.
We are adopting a new airworthiness directive (AD) for certain The Boeing Company Model 747-200B, 747-300, 747-400, 747-400D, and 747- 400F series airplanes. This AD was prompted by a report of cracking in both the aluminum strut side skin, and corrosion resistant steel (CRES) outer spring beam support fitting. This AD requires inspections, related investigative and corrective actions, and a fastener installation modification. We are issuing this AD to address the unsafe condition on these products.
Except as provided by paragraphs (i)(1) and (i)(2) of this AD, at the applicable compliance time specified in paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-54A2245, Revision 1, dated September 20, 2016, do a surface high frequency eddy current (HFEC) inspection for cracking of the strut side skin, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 747-54A2245, Revision 1, dated September 20, 2016, except as required by paragraph (i)(3) of this AD. Repeat the inspection thereafter at the applicable times specified in paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-54A2245, Revision 1, dated September 20, 2016, until the actions required by paragraph (h) of this AD are done. If any cracking is found, do the actions specified in paragraph (h) of this AD before further flight.
Within the applicable compliance time specified in paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-54A2245, Revision 1, dated September 20, 2016, except as provided by paragraphs (i)(1) and (i)(2) of this AD: Do a fastener hole open-hole HFEC inspection for cracking, applicable related investigative and corrective actions, and a fastener installation modification, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 747-54A2245, Revision 1, dated September 20, 2016, except as required by paragraph (i)(3) of this AD. Do all applicable related investigative and corrective actions before further flight. Part numbers 321U2400-5600, 321U2400-5601, and 321U2400-5602 may be used for modification of airplanes with GE CF6-80 engines and PW4000 engines. Doing the actions required by this paragraph terminates the repetitive inspections required by paragraph (g) of this AD.
(1) Where Boeing Alert Service Bulletin 747-54A2245, Revision 1, dated September 20, 2016, specifies a compliance time “after the original issue date of this service bulletin,” this AD requires compliance within the specified compliance time after the effective date of this AD.
(2) The Condition column in table 1 and table 2 of paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-54A2245, Revision 1, dated September 20, 2016, refers to total flight cycles “at the original issue date of this service bulletin.” This AD, however, applies to the airplanes with the specified total flight cycles as of the effective date of this AD.
(3) Although Boeing Alert Service Bulletin 747-54A2245, Revision 1, dated September 20, 2016, specifies to contact Boeing for repair instructions, and specifies that action as “RC” (Required for Compliance), this AD requires repair before further flight using a method approved in accordance with the procedures specified in paragraph (k) of this AD.
