Airworthiness Directive · Amendment 39-17643 · Fuselage
The Boeing Company Airplanes
Superseded. A later AD replaced this one: AD 2016-07-31. Comply with the one in force.
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 1, dated September 19, 2012.
We are superseding Airworthiness Directive (AD) 2009-10-06 for certain The Boeing Company Model 747-400 and -400D series airplanes. AD 2009-10-06 required repetitive inspections to detect cracks in the floor panel attachment fastener holes of the Section 41 upper deck floor beam upper chords, and corrective actions if necessary; and repetitive post-repair and post-modification inspections, and corrective actions if necessary. This new AD adds repetitive inspections of Section 44 upper deck floor beam upper chords, and corrective actions if necessary; repetitive post-repair and post- modification inspections, and corrective actions if necessary; and replacement of the upper deck floor beam upper chords. This AD was prompted by an evaluation by the design approval holder (DAH) indicating that certain upper chords of the upper deck floor beam are subject to widespread fatigue damage (WFD). We are issuing this AD to detect and correct fatigue cracking in certain upper chords of the upper deck floor beam, which could become large and cause the floor beams to become severed and result in rapid decompression or reduced controllability of the airplane.
This paragraph restates the actions required by paragraph (g) of AD 2009-10-06, Amendment 39-15901 (74 FR 22424, May 13, 2009), with revised service information and compliance times. Except as required by paragraphs (h)(1) and (h)(2) of this AD: At the applicable times in paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-53A2688, dated August 21, 2008, do an inspection (open-hole or surface high frequency eddy current (HFEC)) to detect cracks in the floor panel attachment fastener holes of the Section 41 upper deck floor beam upper chords, and do applicable corrective actions, by accomplishing all the applicable actions specified in the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2688, dated August 21, 2008; or Revision 1, dated September 19, 2012. Repeat the inspections thereafter at the applicable times specified in paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-53A2688, dated August 21, 2008, except as required by paragraphs (i) and (m) of this AD. As of the effective date of this AD, use only Boeing Alert Service Bulletin 747-53A2688, Revision 1, dated September 19, 2012, to accomplish the actions in this paragraph.
(1) This paragraph restates the exception stated in paragraph (h) of AD 2009-10-06, Amendment 39-15901 (74 FR 22424, May 13, 2009). If any crack is found during any inspection required by paragraph (g) of this AD, and Boeing Alert Service Bulletin 747-53A2688, dated August 21, 2008; or Revision 1, dated September 19, 2012; specifies to contact Boeing for appropriate action: Before further flight, repair the crack using a method approved in accordance with the procedures specified in paragraph (p) of this AD.
(2) This paragraph restates the exception stated in paragraph (i) of AD 2009-10-06, Amendment 39-15901 (74 FR 22424, May 13, 2009). Where Boeing Alert Service Bulletin 747-53A2688, dated August 21, 2008, specifies a compliance time after the date on the service bulletin, this AD requires compliance within the specified compliance time after June 17, 2009 (the effective date of AD 2009-10-06).
For airplanes on which a repair or modification identified in Table 2 of 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-53A2688, Revision 1, dated September 19, 2012, has been done: At the times specified in Table 2 of paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-53A2688, Revision 1, dated September 19, 2012, except as required by paragraph (n)(3) of this AD, do open-hole and surface HFEC inspections, as applicable, for cracking, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2688, Revision 1, dated September 19, 2012. Repeat at the applicable intervals specified in Table 2 of paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-53A2688, Revision 1, dated September 19, 2012. If any cracking is found in the repaired or modified locations, before further flight, repair the crack using a method approved in accordance with the procedures specified in paragraph (p) of this AD.
For Group 1 airplanes identified in Boeing Alert Service Bulletin 747-53A2688, Revision 1, dated September 19, 2012: At the applicable times specified in paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-53A2688, Revision 1, dated September 19, 2012, except as specified in paragraph (n)(2) of this AD, do an open-hole or surface HFEC inspection to detect cracking in the floor panel attachment fastener holes of the Section 44 upper deck floor beam upper chords, and all applicable corrective actions, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2688, Revision 1, dated September 19, 2012, except as required by paragraph (n)(1) of this AD. Repeat the inspections thereafter at the applicable intervals specified in paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-53A2688, Revision 1, dated September 19, 2012, except as provided by paragraph (m) of this AD. Do all applicable corrective actions before further flight.
(1) For Section 41: Doing a hole modification or repair as a hole modification, in accordance with “Part 2—Section 41—Repair,” of the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2688, Revision 1, dated September 19, 2012, terminates the repetitive inspections specified in paragraph (g) of this AD. However, the repetitive inspections specified in paragraph (i) of this AD must be done.
(2) For Section 44: Doing a hole modification or repair as a hole modification, in accordance with “Part 5—Section 44—Repair,” of the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2688, Revision 1, dated September 19, 2012, terminates the repetitive inspections specified in paragraph (j) of this AD. However, the repetitive inspections specified in paragraph (l) of this AD must be done.
For airplanes on which a repair or modification specified in the “Condition” column of Table 4 of paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-53A2688, Revision 1, dated September 19, 2012, has been done: At the times specified in Table 4 of paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-53A2688, Revision 1, dated September 19, 2012, except as required by paragraph (n)(3) of this AD, do open hole and surface HFEC inspections, as applicable, for cracking, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2688, Revision 1, dated September 19, 2012. Repeat at the applicable intervals specified in Table 4 of paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-53A2688, Revision 1, dated September 19, 2012. If any cracking is found in the repaired or modified locations, before further flight, repair the crack using a method approved in accordance with the procedures specified in paragraph (p) of this AD.
At the time specified in paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-53A2688, Revision 1, dated September 19, 2012: Replace Section 41 and 44 upper deck floor beam upper chords, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2688, Revision 1, dated September 19, 2012. Repeat the inspections required by paragraphs (g) and (j) of this AD within 20,000 flight cycles after doing the replacement. Thereafter, repeat the inspection required by paragraphs (g) and (j) of this AD at the times specified in paragraphs (g) and (j) of this AD.
(1) If any crack is found during any inspection required by paragraph (i), (j), or (l) of this AD, and Boeing Alert Service Bulletin 747-53A2688, Revision 1, dated September 19, 2012, specifies to contact Boeing for appropriate action: Before further flight, repair the crack using a method approved in accordance with the procedures specified in paragraph (p) of this AD.
(2) Where Boeing Alert Service Bulletin 747-53A2688, Revision 1, dated September 19, 2012, specifies a compliance time “after the Revision 1 date of this service bulletin,” this AD requires compliance within the specified compliance time after the effective date of this AD.
(3) Where Table 2 or Table 4 of paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-53A2688, Revision 1, dated September 19, 2012, specifies to contact Boeing for inspections and compliance times: Before further flight, contact the Manager, FAA, Seattle Aircraft Certification Office (ACO), for inspections and compliance times and accomplish the inspections at the given times.
