Airworthiness Directive · Amendment 39-16939 · Windows
The Boeing Company Airplanes
This AD applies to The Boeing Company Model 747-100, 747-100B, 747-100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 747-400, 747-400D, 747-400F, 747SR, and 747SP series airplanes, certificated in any category, as identified in Boeing Service Bulletin 747-56A2012, Revision 1, dated August 12, 2010.
We are superseding an existing airworthiness directive (AD) for all The Boeing Company Model 747-100, 747-100B, 747-100B SUD, 747- 200B, 747-200C, 747-200F, 747-300, 747-400, 747-400D, 747-400F, 747SR, and 747SP series airplanes. That AD currently requires an inspection of the No. 2 and No. 3 windows on the left and right sides of the airplane to determine their part numbers, related investigative and corrective actions if necessary, and repetitive inspections of single pane windows. This new AD requires installing dual pane No. 2 and No. 3 windows. This new AD also removes certain airplanes from the applicability. This AD was prompted by loss of a No. 3 window in flight, which could result in consequent rapid loss of cabin pressure. Loss of the window could also result in crew communication difficulties or incapacitation of the crew. We are issuing this AD to correct the unsafe condition on these products.
This paragraph restates the requirements of paragraph (f) of AD 2007-15-10, Amendment 39-15139 (72 FR 41438, July 30, 2007; as corrected by 72 FR 53923, September 21, 2007), with new service information. Inspect the No. 2 and No. 3 windows on the left and right sides of the airplane to determine their part numbers, and do all the applicable related investigative and corrective actions, by accomplishing all of the actions specified in the Accomplishment Instructions of Boeing Alert Service Bulletin 747-56A2012, dated August 24, 2006; or Boeing Service Bulletin 747-56A2012, Revision 1, dated August 12, 2010; except as required by paragraph (j) of this AD; as applicable. Do all of these actions at the compliance times specified in Tables 1, 2, and 3 of paragraph 1.E. of Boeing Alert Service Bulletin 747-56A2012, dated August 24, 2006; or Boeing Service Bulletin 747-56A2012, Revision 1, dated August 12, 2010; as applicable; except as provided by paragraph (h) of this AD. A review of airplane maintenance records is acceptable in lieu of the inspection if the part numbers of the windows can be conclusively determined from that review. Repeat the related investigative and corrective actions thereafter at the interval specified in Table 2 or 3 of paragraph 1.E. of Boeing Alert Service Bulletin 747-56A2012, dated August 24, 2006; or Boeing Service Bulletin 747-56A2012, Revision 1, dated August 12, 2010; except as required by paragraph (h) of this AD, as applicable. As of the effective date of this AD, only Boeing Service Bulletin 747-56A2012, Revision 1, dated August 12, 2010, except as required by (j) of this AD, may be used. Replacing a window in accordance with paragraph (i) of this AD terminates the requirements of this paragraph for that window.
This paragraph restates the exceptions to the compliance times specified in paragraph (g) of AD 2007-15-10, Amendment 39-15139 (72 FR 41438, July 30, 2007; as corrected by 72 FR 53923, September 21, 2007). Where Tables 1, 2, and 3 of paragraph 1.E. of Boeing Alert Service Bulletin 747-56A2012, dated August 24, 2006, specify counting the compliance time from “* * * after the date on this service bulletin,” this AD requires counting the compliance time from September 4, 2007 (the effective date of AD 2007-15-10, Amendment 39-15139 (72 FR 41438, July 30, 2007; as corrected by 72 FR 53923, September 21, 2007)). After replacing a discrepant window with a new window having part number (P/N) 65B27042-(), 65B27043-(), 65B27046-(), or 65B27047-(), do the initial detailed inspection required in paragraph (g) of this AD of the new window at the applicable compliance time: (1) Within 5,500 flight hours after installing P/N 65B27042-() or 65B27043-(), or (2) Within 22,000 flight hours after installing P/N 65B27046-() or 65B27047-().
Within 6 years after the effective date of this AD, replace all No. 2 windows having P/N 65B27042-() or 65B27046-() with windows having P/N 141U4821-(), 141U4822-(), or 65B07639-(); and replace all No. 3 windows having P/N 65B27043-() or 65B27047-() with windows having P/N 141U4831-(), 141U4832-(), or 65B07640-(), in accordance with “Work Instructions, Part 3—Window Replacement,” of the Accomplishment Instructions of Boeing Service Bulletin 747-56A2012, Revision 1, dated August 12, 2010. Doing this replacement for all windows terminates the actions required by paragraphs (g) and (h) of this AD.
Where Step 4.e., “Work Instructions, Part 2—Window Inspection,” of the Accomplishment Instructions in Boeing Service Bulletin 747-56A2012, Revision 1, dated August 12, 2010, specifies “non-clear damage” as a criterion for window replacement, this AD defines non-clear damage to be any degradation of the transparency of the window, which would hinder the internal or external detailed inspections for fail-safe interlayer cracks, glass pane cracks and chips, and indications of electrical arcing. Replacement for non-clear damage is required by this AD only if the non-clear damage hinders the inspection for fail-safe interlayer cracks, glass pane cracks and chips, or indications of electrical arcing.
As of the effective date of this AD, do not install any No. 2 or No. 3 window having P/N 65B27042-(), 65B27043-(), 65B27046-(), or 65B27047-() that is not new or on which the window flight hours are not known, on any airplanes, unless the actions specified in paragraph (g) of this AD are done.
