Airworthiness Directive · Amendment 39-16268 · Fuselage
The Boeing Company Model 747-200B Series Airplanes
This AD applies to The Boeing Company Model 747-200B series airplanes, certificated in any category, identified as Group 1, Configuration 2, in Boeing Alert Service Bulletin 747-53A2809, dated June 18, 2009.
We are adopting a new airworthiness directive (AD) for certain Model 747-200B series airplanes. This AD requires repetitive inspections for cracking of the fuselage skin lap joints at stringer 6 on the left and right sides from station (STA) 340 to STA 400, a one- time general visual inspection to determine if certain fasteners are installed and to determine if service repair manual (SRM) repairs or repair doublers are installed, and corrective actions if necessary. Doing an optional modification of the stringer 6 lap joints terminates the repetitive inspections for the modified area. This AD results from reviews done by Boeing, which show that airplanes that were modified by Boeing to the stretched upper deck (SUD) configuration require inspection for cracking of the stringer 6 lap joint upper-fastener row earlier than previously expected. We are issuing this AD to detect and correct cracking of the stringer 6 lap joints where certain external doublers were not installed, which could result in rapid decompression and loss of structural integrity 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.
Except as required by paragraphs (h) and (i) of this AD: At the applicable time specified in paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-53A2809, dated June 18, 2009, do the inspections specified in paragraphs (g)(1) and (g)(2) of this AD, and applicable corrective actions, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2809, dated June 18, 2009. Do all applicable corrective actions before further flight. Repeat the inspections specified in paragraph (g)(1) of this AD thereafter at intervals not to exceed 3,000 flight cycles, except as provided by paragraph (j) of this AD.
(1) Inspect the left and right side stringer 6 lap joints from station (STA) 340 to STA 400. The inspections include external detailed and high frequency eddy current (HFEC) inspections for cracks in the skin in areas that have not been modified or repaired as specified in paragraph 3.B., Part 2 or Part 3, respectively, of the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2809, dated June 18, 2009.
(2) Do a one-time general visual inspection of the lap joints to determine if certain fasteners are installed and to determine if structural repair manual (SRM) repairs or repair doublers are installed.
Note 1: For airplanes on which external doublers have been installed on both side of the airplanes in accordance with Boeing Service Bulletin 747-53-2272, Zone 1 modification, no further work is necessary.
Where Boeing Alert Service Bulletin 747-53A2809, dated June 18, 2009, specifies a compliance time after the date on that service bulletin, this AD requires compliance within the specified compliance time after the effective date of this AD.
(i) For any condition in which Boeing Alert Service Bulletin 747-53A2809, dated June 18, 2009, specifies to contact Boeing for appropriate action: those actions must be approved using a method approved in accordance with the procedures specified in paragraph (k) of this AD.
Accomplishing the modification, including the open-hole HFEC inspections to detect skin cracks, and applicable corrective actions, specified in paragraph 3.B., Part 2, of the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2809, dated June 18, 2009, terminates the repetitive inspections and repair requirements specified in paragraph (g) of this AD for the side of the airplane on which the modification is done.
