Airworthiness Directive · Amendment 39-18476 · Fuselage
The Boeing Company Airplanes
This AD applies to The Boeing Company Model 747-400 and -400D series airplanes, certificated in any category, as identified in Boeing Alert Service Bulletin 747-53A2688, Revision 2, dated August 21, 2014.
We are superseding Airworthiness Directive (AD) 2013-22-11 for certain The Boeing Company Model 747-400 and -400D series airplanes. AD 2013-22-11 required repetitive inspections to detect cracks in the floor panel attachment fastener holes of certain upper deck floor beam upper chords, repetitive inspections, corrective actions if necessary, and replacement of the upper deck floor beam upper chords. Since we issued AD 2013-22-11, we received a report that certain fastener holes in the upper deck floor beam upper chords may not have been inspected in accordance with AD 2013-22-11. This AD adds additional repetitive inspections for cracks for certain airplanes, and corrective actions if necessary. We are issuing this AD to detect and correct fatigue cracking in certain upper chords of the upper deck floor beam. Such cracks could become large and cause the floor beams to become severed and result in rapid decompression or reduced controllability of the airplane.
At the applicable time specified in table 1 of paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-53A2688, Revision 2, dated August 21, 2014, do open hole or surface high frequency eddy current inspections (HFEC) for cracking of the floor panel attachment holes in the upper deck floor beam upper chords, in accordance with Part 1 of the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2688, Revision 2, dated August 21, 2014. If any crack is found during any inspection, before further flight, repair in accordance with Part 2 of the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2688, Revision 2, dated August 21, 2014, or repair using a method approved in accordance with the procedures specified in paragraph (o) of this AD. Repeat the inspections thereafter at the applicable time specified in table 1 of paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-53A2688, Revision 2, dated August 21, 2014, until an action specified in paragraph (g)(1) or (g)(2) of this AD is done.
(1) Doing a repair as a hole modification in accordance with Part 2 of the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2688, Revision 2, dated August 21, 2014, except as required by paragraph (m)(2) of this AD, terminates the inspections required by paragraph (g) of this AD for the modified hole only.
(2) Doing a modification in accordance with Figure 5 of the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2688, Revision 2, dated August 21, 2014, except as required by paragraph (m)(2) of this AD, terminates the inspections required by paragraph (g) of this AD for the modification only.
For airplanes on which a repair specified in Part 2 of the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2688, Revision 2, dated August 21, 2014, is done, or a modification specified in Figure 5 of the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2688, Revision 2, dated August 21, 2014, is done: At the applicable time specified in table 2 of paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-53A2688, Revision 2, dated August 21, 2014, except as required by paragraph (m)(3) of this AD, do open hole or surface HFEC for cracking of repaired or modified floor panel attachment holes in the upper deck floor beam upper chords, in accordance with Part 1 or Part 3, as applicable, of the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2688, Revision 2, dated August 21, 2014. If any crack is found during any inspection required by this paragraph, before further flight, repair using a method approved in accordance with the procedures specified in paragraph (o) of this AD. Repeat the inspections thereafter at the applicable time specified in table 2 of paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-53A2688, Revision 2, dated August 21, 2014.
For airplanes identified in Group 1 in Boeing Alert Service Bulletin 747-53A2688, Revision 2, dated August 21, 2014: At the applicable time specified in table 3 of paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-53A2688, Revision 2, dated August 21, 2014, except as required by paragraph (m)(4) of this AD, do open hole or surface HFEC inspections of the floor panel attachment holes in the upper deck floor beam upper chords, in accordance with Part 4 of the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2688, Revision 2, dated August 21, 2014. If any crack is found during any inspection required by this paragraph, before further flight, repair in accordance with Part 5 of the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2688, Revision 2, dated August 21, 2014, except as required by paragraph (m)(2) of this AD. Repeat the inspections thereafter at the applicable time specified in table 3 of paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-53A2688, Revision 2, dated August 21, 2014, until an action specified in paragraph (i)(1) or (i)(2) of this AD is done.
(1) Doing a repair as a hole modification in accordance with Part 5 of the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2688, Revision 2, dated August 21, 2014, except as required by paragraph (m)(2) of this AD, terminates the inspections required by paragraph (i) of this AD for that modified hole only.
(2) Doing a modification in accordance with Figure 21 of the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2688, Revision 2, dated August 21, 2014, except as required by paragraph (m)(2) of this AD, terminates the inspections required by paragraph (i) of this AD for that modified hole only.
For airplanes identified in Group 1 in Boeing Alert Service Bulletin 747-53A2688, Revision 2, dated August 21, 2014, on which a repair specified in Part 5 of Boeing Alert Service Bulletin 747-53A2688, Revision 2, dated August 21, 2014, is done or the modification specified in Figure 21 of the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2688, Revision 2, dated August 21, 2014, is done: At the applicable time specified in table 4 of paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-53A2688, Revision 2, dated August 21, 2014, except as required by paragraph (m)(3) of this AD, do open hole or surface HFEC inspections of repaired or modified floor panel attachment holes in the upper deck floor beam upper chords, in accordance with Part 4 or Part 6, as applicable, of the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2688, Revision 2, dated August 21, 2014. If any crack is found during any inspection by this paragraph, before further flight, repair using a method approved in accordance with the procedures specified in paragraph (o) of this AD. Repeat the inspections thereafter at the applicable time specified in table 4 of paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-53A2688, Revision 2, dated August 21, 2014.
At the applicable time specified in table 5 of paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-53A2688, Revision 2, dated August 21, 2014: Replace all upper deck floor beam upper chords, in accordance with Part 7 of the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2688, Revision 2, dated August 21, 2014. Within 20,000 flight cycles after doing the replacement, do the inspections specified in paragraphs (g) and (i) of this AD, as applicable. Thereafter, repeat the inspections required by paragraphs (g) and (i) of this AD, as applicable, at the times specified in paragraphs (g) and (i) of this AD.
For airplanes identified in Group 2 in Boeing Alert Service Bulletin 747-53A2688, Revision 2, dated August 21, 2014: At the applicable time specified in table 6 of paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-53A2688, Revision 2, dated August 21, 2014, except as required by paragraph (m)(1) of this AD, at all plugged or reused floor panel attachment holes in the affected floor beam upper chords, do a surface HFEC inspection of the upper deck floor beam upper chords and detailed inspection for cracks on the vertical flange, in accordance with Part 8 of the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2688, Revision 2, dated August 21, 2014. If any crack is found during any inspection required by this paragraph, before further flight, repair using a method approved in accordance with the procedures specified in paragraph (o) of this AD. Repeat the inspections thereafter at the applicable time specified in table 6 of paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-53A2688, Revision 2, dated August 21, 2014.
(1) Where Boeing Alert Service Bulletin 747-53A2688, Revision 2, dated August 21, 2014, specifies a compliance time “after the Revision 2 date of this service bulletin,” this AD requires compliance within the specified compliance time after the effective date of this AD.
(2) Where Boeing Alert Service Bulletin 747-53A2688, Revision 2, dated August 21, 2014; specifies to contact Boeing for certain procedures: Do the specified actions before further flight using a method approved in accordance with the procedures specified in paragraph (o) of this AD.
(3) Where table 2 or table 4 of paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-53A2688, Revision 2, dated August 21, 2014, specifies to contact Boeing for inspections and compliance times: Before further flight, contact the Manager, Seattle Aircraft Certification Office (ACO), FAA, for inspections and compliance times and accomplish the inspections at the given times.
(4) Where Boeing Alert Service Bulletin 747-53A2688, Revision 2, dated August 21, 2014, specifies a compliance time “after the Revision 1 date of this service bulletin,” this AD requires compliance within the specified compliance time after December 10, 2013 (the effective date of AD 2013-22-11).
