Airworthiness Directive · Amendment 39-16188 · Fuselage
The Boeing Company Model 747-200C and -200F Series Airplanes
Superseded. A later AD replaced this one: AD 2014-20-07. Comply with the one in force.
This AD applies to all The Boeing Company Model 747-200C and -200F series airplanes, certificated in any category.
We are adopting a new airworthiness directive (AD) for all Model 747-200C and -200F series airplanes. This AD requires a high frequency eddy current (HFEC) inspection for cracks of certain fastener holes, and corrective action if necessary. This AD also requires repetitive replacements of the upper chords, straps (or angles), and radius fillers of certain upper deck floor beams, and, for any replacement that is done, detailed and open-hole HFEC inspections for cracks of the modified upper deck floor beams, and corrective actions if necessary. This AD results from a report from the manufacturer that the accomplishment of certain existing inspections, repairs, and modifications is not adequate to ensure the structural integrity of the affected 7075 series aluminum alloy upper deck floor beam upper chords on airplanes that have exceeded certain thresholds. We are issuing this AD to prevent cracking of the upper chords and straps (or angles) of the floor beams, which could lead to failure of the floor beams and consequent loss of controllability, rapid decompression, and loss of structural integrity of the airplane.
Comply with this AD within the compliance times specified, unless already done.
Before the accumulation of 21,000 total flight cycles, or within 1,500 flight cycles after the effective date of this AD, whichever occurs later: Do an open-hole high frequency eddy current (HFEC) inspection of all the fastener holes accessed for upper chord removal for cracks, and replace the upper chords, straps (or angles), and radius fillers of the upper deck floor beams, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2696, dated October 16, 2008.
Within 15,000 flight cycles after doing the replacement required by paragraph (g) of this AD, or within 1,500 flight cycles after the effective date of this AD, whichever occurs later: Do detailed and HFEC inspections for cracks of the modified upper deck floor beams, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2696, dated October 16, 2008. Within 6,000 flight cycles after doing the detailed and HFEC inspections, repeat the replacement specified in paragraph (g) of this AD. Repeat the post-replacement inspections and replacement at the applicable times specified in paragraph 1.E. of Boeing Alert Service Bulletin 747-53A2696, dated October 16, 2008.
(i) If any crack is found during any inspection required by this AD: Before further flight, repair the crack using a method approved in accordance with the procedures specified in paragraph (j) of this AD.
