Airworthiness Directive · Amendment 39-19630 · Nacelles/pylons
The Boeing Company Airplanes
This AD applies to all The Boeing Company Model 747-8 and 747-8F series airplanes, certificated in any category.
We are adopting a new airworthiness directive (AD) for all The Boeing Company Model 747-8 and 747-8F series airplanes. This AD was prompted by reports of damaged vapor seals, block seals, and heat shield seals on the outboard pylons between the engine strut and aft fairing. This AD requires installing new aft fairing vapor seals, heatshield seals, heatshield seal retainers, block seals, and outboard lateral restraint access panels. We are issuing this AD to address the unsafe condition on these products.
(1) For airplanes identified in Boeing Alert Service Bulletin 747-54A2247, dated August 3, 2017: Except as required by paragraph (h) of this AD, at the applicable times specified in paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-54A2247, dated August 3, 2017, do all applicable actions identified as “RC” (required for compliance) in, and in accordance with, the Accomplishment Instructions of Boeing Alert Service Bulletin 747-54A2247, dated August 3, 2017.
(2) For airplanes not identified in Boeing Alert Service Bulletin 747-54A2247, dated August 3, 2017: Within 4 years or 4,800 flight cycles after the effective date of this AD, whichever occurs first, inspect to determine if any part number identified in paragraphs (g)(2)(i) through (g)(2)(v) of this AD is installed. If any part number specified in paragraphs (g)(2)(i) through (g)(2)(v) of this AD is installed, within 4 years or 4,800 flight cycles after the effective date of this AD, whichever occurs first, replace the part with a part number that is identified as an acceptable replacement in Boeing Alert Service Bulletin 747-54A2247, dated August 3, 2017. A review of airplane maintenance records is acceptable in lieu of this inspection if the part numbers specified in paragraphs (g)(2)(i) through (g)(2)(v) of this AD can be conclusively determined from that review.
(i) An access panel lateral restraint with part number (P/N) 321U8595-1, 321U8595-2, 321U8595-3, or 321U8595-4.
(ii) A block seal with P/N 323U8452-2.
(iii) A vapor seal with P/N 323U8452-3.
(iv) A heatshield seal with P/N 323U8852-1.
(v) A heatshield seal retainer P/N 323U8852-2.
For purposes of determining compliance with the requirements of this AD: Where Boeing Alert Service Bulletin 747-54A2247, dated August 3, 2017, uses the phrase “the original issue date of this service bulletin,” this AD requires using “the effective date of this AD.”
Accomplishing the actions specified in paragraphs (g)(1) or (g)(2) of this AD, as applicable, terminates all requirements of AD 2017-04-13.
The aircraft, engines and makers this AD names, by the model designations in its text. A model listed here may still be outside the AD's serial ranges.
Aircraft
