Airworthiness Directive · Amendment 39-18872 · Wings
The Boeing Company Airplanes
This AD applies to all The Boeing Company Model 747-400, 747-400D, and 747-400F airplanes, certificated in any category.
We are adopting a new airworthiness directive (AD) for all The Boeing Company Model 747-400, 747-400D, and 747-400F airplanes. This AD was prompted by a report of a crack in the left wing front spar web, found following a fuel leak. This AD requires repetitive inspections for cracking of the front spar web, and repairs if necessary. 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 747-57A2357, dated September 12, 2016, except as provided by paragraph (i) of this AD, do detailed, ultrasonic, and high frequency eddy current inspections for any cracking in the front spar web, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 747-57A2357, dated September 12, 2016. Repeat the inspections thereafter at the applicable time specified in paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-57A2357, dated September 12, 2016.
If any crack is found during any inspection required by paragraph (g) of this AD, before further flight, repair using a method approved in accordance with the procedures specified in paragraph (j) of this AD. Thereafter, repeat the inspections specified in paragraph (g) of this AD at all unrepaired areas.
Where paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-57A2357, dated September 12, 2016, specifies a compliance time “after the original date of this service bulletin,” this AD requires compliance within the specified compliance time after the effective date of this AD.
