Airworthiness Directive · Amendment 39-15653 · Boeing Model 737-600, -700, -800, and -900 Series Airplanes
Boeing Model 737-600, -700, -800, and -900 Series Airplanes
This AD applies to Boeing Model 737-600, -700, -800, and -900 series airplanes, certificated in any category; as identified in Boeing Alert Service Bulletin 737-28A1221, Revision 1, dated November 9, 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 (AMOC) 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 737-600, -700, -800, and -900 series airplanes. This AD requires installing hot short protector (HSP) support brackets and equipment for the fuel quantity indicating system (FQIS) fuel densitometer and other specified actions as applicable. This AD also requires revising the Airworthiness Limitations (AWLs) section of the Instructions for Continued Airworthiness to incorporate AWL No. 28-AWL- 07. This AD results from fuel system reviews conducted by the manufacturer. We are issuing this AD to prevent the center tank fuel densitometer from overheating and becoming a potential ignition source inside the center fuel tank, which, in combination with flammable fuel vapors, could result in a center 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, install the HSP support brackets and equipment for the fuel quantity indicating system (FQIS) fuel densitometer and do all the other specified actions as applicable, by accomplishing all of the applicable actions specified in the Accomplishment Instructions of Boeing Alert Service Bulletin 737-28A1221, Revision 1, dated November 9, 2007.
Concurrently with accomplishing the actions required by paragraph (f) of this AD, revise the AWLs section of the Instructions for Continued Airworthiness (ICA) by incorporating AWL No. 28-AWL-07 of Subsection F, “AIRWORTHINESS LIMITATIONS—FUEL SYSTEM AWLs,” of Section 9 of the Boeing 737-600/700/800/900 Maintenance Planning Data (MPD) Document, D626A001-CMR, Revision March 2007 R2 (hereafter referred to as “the MPD”).
After accomplishing the action specified in paragraph (g) of this AD, no alternative CDCCLs may be used unless the CDCCLs are approved as an alternative methods of compliance (AMOC) in accordance with the procedures specified in paragraph (k) of this AD.
(i) Actions done before the effective date of this AD in accordance with Boeing Alert Service Bulletin 737-28A1221, dated January 14, 2007, are acceptable for compliance with the requirements of paragraph (f) of this AD.
Incorporating AWL No. 28-AWL-07 into the AWLs section of the ICA in accordance with paragraph (g)(3) of AD 2008-10-10, amendment 39-15516, terminates the action required by paragraph (g) of this AD.
