Airworthiness Directive · Amendment 39-16221 · Equipment/furnishings
The Boeing Company Model 747-100, 747-200B, 747-300, and 747SR Series Airplanes
This AD applies to The Boeing Company Model 747-100, 747-200B, 747-300, and 747SR series airplanes, certificated in any category; as identified in Boeing Service Bulletin 747-25A3368, Revision 2, dated June 12, 2008.
Note 1: The affected airplanes are those that have been converted by Boeing to the Boeing Special Freighter configuration.
We are adopting a new airworthiness directive (AD) for certain Model 747-100, 747-200B, 747-300, and 747SR series airplanes. This AD requires installation of a closeout panel and moisture curtains for the main equipment center. This AD results from a report of water contamination in the electrical and electronic units in the main equipment center. We are issuing this AD to prevent the malfunction of one or more electrical and electronic units in the main equipment center, which could adversely affect the airplane's continued safe flight.
You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done.
Within 24 months after the effective date of this AD, install the closeout panel and moisture curtains for the main equipment center, by accomplishing all of the applicable actions specified in the Accomplishment Instructions of Boeing Service Bulletin 747-25A3368, Revision 2, dated June 12, 2008.
Actions done before the effective date of this AD in accordance with the Accomplishment Instructions in Boeing Alert Service Bulletin 747-25A3368, dated August 25, 2005, are acceptable for compliance with the corresponding actions required by paragraph (g) of this AD, provided that the additional work specified in the Accomplishment Instructions of Boeing Alert Service Bulletin 747-25A3368, Revision 1, dated June 25, 2007; or Revision 2, dated June 12, 2008; is accomplished. The additional work required is to cap seal all rivets fastening the mounting base assembly to the moisture shroud as given in Figure 10 in Boeing Alert Service Bulletin 747-25A3368, Revision 2, dated June 12, 2008, and to fill any unused pilot holes in the mounting base assembly in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 747-25A3368, Revision 2, dated June 12, 2008; or cap seal all rivets fastening the mounting base assembly to the moisture shroud as given in Figure 10 of Boeing Alert Service Bulletin 747-25A3368, Revision 1, dated June 25, 2007, and to fill any unused pilot holes in the mounting base assembly in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 747-25A3368, Revision 1, dated June 25, 2007.
(i) Actions done before the effective date of this AD in accordance with Boeing Alert Service Bulletin 747-25A3368, Revision 1, dated June 25, 2007, are acceptable for compliance with the corresponding actions required by paragraph (g) of this AD.
