Airworthiness Directive · Amendment 39-15666 · Boeing Model 747 Airplanes
Boeing Model 747 Airplanes
This AD applies to Boeing 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 Alert Service Bulletin 747-28A2291, dated September 27, 2007.
Note 1: This AD requires revisions to certain operator maintenance documents to include new inspections. Compliance with these inspections is required by 14 CFR 91.403(c). For airplanes that have been previously modified, altered, or repaired in the areas addressed by these inspections, the operator may not be able to accomplish the inspections described in the revisions. In this situation, to comply with 14 CFR 91.403(c), the operator must request approval for an alternative method of compliance according to paragraph (k) of this AD. The request should include a description of changes to the required inspections that will ensure the continued operational safety of the airplane.
We are adopting a new airworthiness directive (AD) for certain Boeing Model 747 airplanes. This AD requires modification of the refuel valve control unit for the reserve fuel tanks. This AD also requires a revision to the FAA-approved maintenance program to incorporate airworthiness limitation (AWL) No. 28-AWL-20 or AWL No. 28-AWL-25, as applicable. This AD results from fuel system reviews conducted by the manufacturer. We are issuing this AD to prevent lightning-induced electrical energy from entering a reserve fuel tank through the refuel valve, which could result in a fuel tank explosion and consequent loss of the airplane.
Comply with this AD within the compliance times specified, unless already done.
Within 60 months after the effective date of this AD, modify the refuel valve control unit for the reserve fuel tanks, by accomplishing all of the applicable actions specified in the Accomplishment Instructions of Boeing Alert Service Bulletin 747-28A2291, dated September 27, 2007.
Concurrently with accomplishing the modification required by paragraph (f) of this AD, revise the FAA-approved maintenance program by incorporating the information specified in paragraph (g)(1) or (g)(2) of this AD, as applicable.
(1) For Model 747-100, 747-100B, 747-100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 747SR, and 747SP series airplanes: Incorporate AWL No. 28-AWL-20 of Section D of the Boeing 747-100/200/300/SP Airworthiness Limitations (AWLs) and Certification Maintenance Requirements (CMRs), D6-13747-CMR, Revision January 2007, into the FAA-approved maintenance program.
(2) For Model 747-400, 747-400D, and 747-400F series airplanes: Incorporate AWL No. 28-AWL-25 of Subsection D of the Boeing 747-400 Maintenance Planning Data (MPD) Document, D621U400-9, Section 9, Revision 24, dated June 2006, into the FAA-approved maintenance program.
After accomplishing the applicable action specified in paragraph (g) of this AD, no alternative CDCCLs may be used unless the CDCCLs are approved as an AMOC in accordance with the procedures specified in paragraph (k) of this AD.
(i) For Model 747-100, 747-100B, 747-100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 747SR, and 747SP series airplanes: Incorporating AWL No. 28-AWL-20 into the FAA-approved maintenance program in accordance with paragraph (g) of AD 2008-10-07, amendment 39-15513, terminates the action required by paragraph (g)(1) of this AD.
(j) For Model 747-400, 747-400D, and 747-400F series airplanes: Incorporating AWL No. 28-AWL-25 into the FAA-approved maintenance program in accordance with paragraph (g)(3) of AD 2008-10-06, amendment 39-15512, terminates the action required by paragraph (g)(2) of this AD.
