Airworthiness Directive · Amendment 39-16343 · Fuel
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
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 Alert Service Bulletin 747-28A2261, dated February 19, 2009.
Note 1: This AD requires a revision to a certain operator maintenance document to include new inspections. Compliance with these inspections is required by 14 CFR 43.16 and 91.403(c). For airplanes that have been previously modified, altered, or repaired in the areas addressed by these limitations, the operator may not be able to accomplish the actions described in the revisions. In this situation, to comply with 14 CFR 43.16 and 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 Model 747 series airplanes. This AD requires replacing the power control relays for the main tank fuel boost pumps and jettison pumps, and the center tank scavenge pump, as applicable, with new relays having a ground fault interrupt (GFI) feature. This AD also requires revising the maintenance program to incorporate Airworthiness Limitations (AWLs) 28-AWL-23 (for Model 747-100, 747-100B, 747-100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 747SP, and 747SR series airplanes), and AWLs 28-AWL-28 and 28-AWL-29 (for Model 747-400, 747- 400D, and 747-400F series airplanes). This AD results from fuel system reviews conducted by the manufacturer. We are issuing this AD to prevent damage to the fuel pumps caused by electrical arcing that could introduce an ignition source in the fuel tank, which, in combination with flammable fuel vapors, could result in a fuel tank explosion and consequent loss 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.
Within 60 months after the effective date of this AD: Replace the power control relays for the main tank fuel boost pumps and jettison pumps, and the center tank scavenge pump, as applicable, with new relays having a ground fault interrupt feature, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 747-28A2261, dated February 19, 2009.
Concurrently with the actions required by paragraph (g) of this AD: Revise the maintenance program by incorporating the applicable information in paragraphs (h)(1) and (h)(2) of this AD. The inspection interval for airworthiness limitations (AWLs) 28-AWL-23, 28-AWL-28, and 28-AWL-29 starts on the date the replacement required by paragraph (g) of this AD is done.
(1) For Model 747-400, 747-400D, and 747-400F series airplanes: Incorporate new airworthiness limitations 28-AWL-28 and 28-AWL-29 of Subsection D, “AIRWORTHINESS LIMITATIONS—FUEL SYSTEMS,” of Boeing 747-400 Maintenance Planning Data (MPD) Document, Document D621U400-9, Section 9, Revision December 2009. (These AWLs were first introduced in Revision October 2007 of the MPD document.) Incorporating AWLs 28-AWL-28 and 28-AWL-29 in accordance with paragraph (g)(3) of AD 2008-10-06, Amendment 39-15512; or AD 2008-10-06 R1, Amendment 39-16160; is acceptable for compliance with the corresponding requirements specified in this paragraph.
(2) For Model 747-100, 747-100B, 747-100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 747SP, and 747SR series airplanes: Incorporate new AWL 28-AWL-23 of Subsection D, “AIRWORTHINESS LIMITATIONS—SYSTEMS,” of Boeing 747-100/200/300/SP Airworthiness Limitations (AWLs) and Certification Maintenance Requirements (CMRs), Document D6-13747-CMR, Revision March 2008. (This AWL was first introduced in Revision September 2007 of the AWLs/CMRs document.) Incorporating AWL 28-AWL-23 in accordance with paragraph (g) of AD 2008-10-07, Amendment 39-15513; or AD 2008-10-07 R1, Amendment 39-16070; is acceptable for compliance with the corresponding requirements specified in this paragraph.
(i) After accomplishing the actions required by paragraph (h) of this AD, no alternative inspections or inspection intervals may be used, unless the inspections or intervals are approved as an alternative method of compliance (AMOC) in accordance with the procedures specified in paragraph (k) of this AD.
Incorporating new AWLs 28-AWL-28 and 28-AWL-29 of Subsection D, “AIRWORTHINESS LIMITATIONS—FUEL SYSTEMS,” of Boeing 747-400 Maintenance Planning Data (MPD) Document, Document D621U400-9, Section 9, Revision April 2008; or Revision March 2009; before the effective date of this AD is acceptable for compliance with the requirements of paragraph (h)(1) of this AD.
