Airworthiness Directive · Amendment 39-14215 · Boeing Model 747-400 and 747-400D Series Airplanes
Boeing Model 747-400 and 747-400D Series Airplanes
This AD applies to Boeing Model 747-400 and 747-400D series airplanes, certificated in any category, as listed in Boeing Alert Service Bulletin 747-53A2503, dated November 11, 2004.
The FAA is adopting a new airworthiness directive (AD) for certain Boeing Model 747-400 and 747-400D series airplanes. This AD requires an inspection for corrosion and cracks of the station 980 upper deck floor beam, and repair and related investigative actions if necessary. This AD results from reports of corrosion under the cart lift threshold at the station 980 upper deck floor beam. We are issuing this AD to detect and correct such corrosion, which could result in a cracked or broken floor beam, extensive damage to adjacent structure, and possible rapid decompression 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.
At the later of the times specified in paragraphs (f)(1) and (f)(2) of this AD: Do a detailed inspection for corrosion and cracks of the station 980 upper deck floor beam, in accordance with Boeing Alert Service Bulletin 747-53A2503, dated November 11, 2004.
(1) Inspect within 120 months since the date of issuance of the original standard Airworthiness Certificate or the date of issuance of the original Export Certificate of Airworthiness; or
(2) Inspect at the time specified in paragraph (f)(2)(i), (f)(2)(ii), or (f)(2)(iii) of this AD for the applicable airplane group as identified in the service bulletin.
(i) For Group 1 airplanes: Within 18 months after the effective date of this AD.
(ii) For Group 2 airplanes: Within 36 months after the effective date of this AD.
(iii) For Group 3 airplanes: Within 120 months after the airplane has been modified in accordance with Boeing Service Bulletin 747-25-3107, or within 36 months after the effective date of this AD, whichever occurs later.
If any cracking or corrosion is found during any inspection required by this AD, do all related investigative and corrective actions before further flight, in accordance with Boeing Alert Service Bulletin 747-53A2503, dated November 11, 2004. If the service bulletin specifies to contact Boeing for appropriate action, repair before further flight according to a method approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA; or according to data meeting the certification basis of the airplane approved by an Authorized Representative 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 approval must specifically reference this AD.
