Airworthiness Directive · Amendment 39-18788 · Fuselage
The Boeing Company Airplanes
This AD applies to The Boeing Company Model 747-400, -400D, and -400F series airplanes, certificated in any category, as identified in Boeing Alert Service Bulletin 747-53A2878, dated May 19, 2016.
We are adopting a new airworthiness directive (AD) for certain The Boeing Company Model 747-400, -400D, and -400F series airplanes. This AD was prompted by widespread corrosion damage that was found on the skin inner surface along the upper bulkhead at certain stations between certain stringers. This AD requires repetitive inspections of the fuselage crown skin inner surface, and related investigative and corrective actions if necessary. This AD also allows for terminating actions for the repetitive inspections. We are issuing this AD to address the unsafe condition on these products.
At the applicable time specified in paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-53A2878, dated May 19, 2016, except as required by paragraph (k)(1) of this AD: Do a detailed inspection of the skin inner surface for any missing or degraded finish, sign of corrosion, or crack, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2878, dated May 19, 2016. Repeat the inspection thereafter at intervals not to exceed the applicable time specified in paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-53A2878, dated May 19, 2016, until the actions specified in paragraph (i) of this AD have been done.
If any damage is found during any inspection required by paragraph (g) of this AD, before further flight, do all applicable related investigative and correction actions, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2878, dated May 19, 2016, except as required by paragraph (k)(2) of this AD.
Modification or repair of the inner skin surfaces, and restoration of the surface finish, in accordance with part 3 and part 4, respectively, of the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2878, dated May 19, 2016, terminates the repetitive inspections required by paragraph (g) of this AD.
For airplanes on which a repair or modification has been done in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2878, dated May 19, 2016: Except as required by paragraph (k)(1) of this AD, at the applicable time specified in Table 3 of paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-53A2878, dated May 19, 2016, do detailed inspections to detect damage of the repaired or modified areas, and do all applicable corrective actions, in accordance with part 5 of the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2878, dated May 19, 2016, except as required by paragraph (k)(2) of this AD. Do all applicable corrective actions before further flight. Repeat the inspections thereafter at intervals not to exceed the applicable time specified in paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-53A2878, dated May 19, 2016.
(1) Where Boeing Alert Service Bulletin 747-53A2878, dated May 19, 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) If any cracking or corrosion is found during any inspection required by this AD, and Boeing Alert Service Bulletin 747-53A2878, dated May 19, 2016, specifies to contact Boeing for appropriate action: Before further flight, repair the cracking or corrosion using a method approved in accordance with the procedures specified in paragraph (l) of this AD.
