Airworthiness Directive · Amendment 39-16627 · Fuel
The Boeing Company Model 747 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 747-28A2292, Revision 3, dated December 9, 2010.
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 (AMOC) according to paragraph (q) 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 the products listed above. This AD requires measuring the electrical bond resistance between the motor operated valve (MOV) actuators and airplane structure for the main, center, auxiliary, and horizontal stabilizer fuel tanks, as applicable, and corrective action if necessary; revising the maintenance program to incorporate airworthiness limitation (AWL) No. 28-AWL-21 or AWL No. 28-AWL-27, as applicable; and replacing production-installed laminate phenolic spacers with metallic spacers between the fuel jettison MOV and the airplane structure, as applicable. This AD was prompted by fuel system reviews conducted by the manufacturer. We are issuing this AD to prevent electrical current from flowing through an MOV actuator into a fuel tank, which could create a potential ignition source inside the fuel tank. This condition, 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, do the actions required by paragraphs (g)(1) and (g)(2) of this AD, as applicable.
(1) Measure the electrical bond resistance between the MOV actuators and the airplane structure for the main, center, and auxiliary fuel tanks, as applicable; and do all applicable corrective actions; by accomplishing all of the applicable actions in the Accomplishment Instructions of Boeing Service Bulletin 747-28A2292, Revision 3, dated December 9, 2010. The corrective actions must be accomplished before further flight.
(2) For airplanes in Groups 12, 16, 17, 18, and 19, as identified in Boeing Service Bulletin 747-28A2292, Revision 3, dated December 9, 2010: Within 60 months after the effective date of this AD, replace production-installed laminate phenolic spacers with metallic spacers, in accordance with the Accomplishment Instructions of Boeing Service Bulletin 747-28A2292, Revision 3, dated December 9, 2010.
(h) For airplanes identified in Boeing Service Bulletin 747-28A2294, Revision 1, dated March 5, 2009: Within 60 months after the effective date of this AD, measure the electrical bond resistance between the MOV actuators and airplane structure for the horizontal stabilizer fuel tanks (HST), and do all the applicable corrective actions, in accordance with the Accomplishment Instructions of Boeing Service Bulletin 747-28A2294, Revision 1, dated March 5, 2009. The corrective actions must be accomplished before further flight.
(i) For airplanes identified in Boeing Service Bulletin 747-28A2294, Revision 1, dated March 5, 2009: Deactivation of the HST, in accordance with the applicable Boeing service information specified in table 1 of this AD, terminates the requirements of paragraph (h) of this AD, except as provided by paragraph (j) of this AD. Deactivation of the HST before the effective date of this AD in accordance with the applicable service information specified in table 2 of this AD also terminates the requirements of paragraph (h) of this AD, except as provided by paragraph (j) of this AD.
| Boeing— | Revision— | Dated— |
|---|---|---|
| Service Bulletin 747-28-2265 | Original | February 22, 2006. |
| Service Bulletin 747-28-2272 | Original | February 21, 2006. |
| Service Bulletin 747-28-2274 | 1 | May 21, 2008. |
| Service Bulletin 747-28-2275 | 4 | February 2, 2009. |
| Service Bulletin 747-28-2279 | 2 | October 16, 2007. |
| Service Bulletin 747-28-2285 | 3 | August 30, 2007. |
| Service Bulletin 747-28-2293 | 2 | March 4, 2008. |
| Service Bulletin 747-28-2295 | 2 | January 19, 2009. |
| Service Bulletin 747-28-2296 | Original | July 13, 2007. |
| Service Bulletin 747-28-2300 | 1 | June 2, 2008. |
| Service Bulletin 747-28-2314 | Original | December 9, 2008. |
| Boeing— | Revision— | Dated— |
|---|---|---|
| Service Bulletin 747-28-2274 | Original | March 13, 2006. |
| Service Bulletin 747-28-2275 | Original | June 12, 2006. |
| Service Bulletin 747-28-2275 | 1 | March 16, 2007. |
| Service Bulletin 747-28-2275 | 2 | July 2, 2007. |
| Service Bulletin 747-28-2275 | 3 | March 11, 2008. |
| Service Bulletin 747-28-2279 | Original | June 12, 2006. |
| Service Bulletin 747-28-2279 | 1 | May 25, 2007. |
| Service Bulletin 747-28-2285 | Original | January 23, 2007. |
| Service Bulletin 747-28-2285 | 1 | May 9, 2007. |
| Service Bulletin 747-28-2285 | 2 | August 3, 2007. |
| Service Bulletin 747-28-2293 | Original | May 9, 2007. |
| Service Bulletin 747-28-2293 | 1 | August 29, 2007. |
| Service Bulletin 747-28-2295 | Original | November 17, 2006. |
| Service Bulletin 747-28-2295 | 1 | March 20, 2008. |
| Service Bulletin 747-28-2300 | Original | January 16, 2008. |
For airplanes identified in Boeing Service Bulletin 747-28A2294, Revision 1, dated March 5, 2009, on which the HST is reactivated, the HST must be reactivated in accordance with a method approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA. For any airplane on which the HST is reactivated, the requirements of paragraphs (h) and (l) of this AD must be done before further flight following the reactivation, or within 60 months after the effective date of this AD, whichever occurs later. For a reactivation method to be approved, the reactivation method must meet the certification basis of the airplane, and the approval must specifically reference this AD.
For Model 747-100, 747-100B, 747-100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 747SR, and 747SP series airplanes: Concurrently with accomplishing the actions required by paragraph (g)(1) of this AD, revise the maintenance program by incorporating airworthiness limitation (AWL) No. 28-AWL-21 of Section D of Boeing 747-100/200/300/SP Airworthiness Limitations (AWLs) and Certification Maintenance Requirements (CMRs), Document D6-13747-CMR, Revision March 2008.
(l) For Model 747-400, 747-400D, and 747-400F series airplanes: Concurrently with accomplishing the actions required by paragraph (g)(1) of this AD, revise the maintenance program by incorporating AWL No. 28-AWL-27 of Subsection D of Boeing 747-400 Maintenance Planning Data (MPD) Document, Section 9, D621U400-9, Revision December 2009.
After accomplishing the applicable action required in paragraph (k) or (l) 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 (q) of this AD.
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-21 into the maintenance program in accordance with paragraph (g) of AD 2008-10-07, Amendment 39-15513; or AD 2008-10-07 R1, Amendment 39-16070; terminates the action required by paragraph (k) of this AD.
Actions done before the effective date of this AD in accordance with Boeing Alert Service Bulletin 747-28A2294, dated September 21, 2007; and Boeing Service Bulletin 747-28A2292, Revision 2, dated May 13, 2010; are acceptable for compliance with the corresponding requirements of this AD.
Incorporation of AWL No. 28-AWL-21 of Section D of the Boeing 747-100/200/300/SP Airworthiness Limitations (AWLs) and Certification Maintenance Requirements (CMRs), Document D6-13747-CMR, Revision January 2007, September 2007, or January 2008, is acceptable for compliance with the corresponding requirements of this AD if done before the effective date of this AD.
