Airworthiness Directive · Amendment 39-13855 · Boeing Model 737-600, -700, -700C, -800, and -900 Series Airplanes
Boeing Model 737-600, -700, -700C, -800, and -900 Series Airplanes
Model 737-600, -700, -700C, -800, and -900 series airplanes, line numbers 1 through 946 inclusive; certificated in any category.
This amendment adopts a new airworthiness directive (AD), applicable to certain Boeing Model 737-600, -700, -700C, -800, and -900 series airplanes, that requires a general visual inspection for sealant at the interface between the diagonal brace fitting and the aft bulkhead and at the four bolts common to the interface. It also requires applying sealant if none is present or if it is not continuous. This action is necessary to prevent flammable fluid in the upper or rear pylon areas from leaking past unsealed areas and onto a hot engine nozzle, which could result in ignition of the fluid, causing an undetected and uncontrollable fire to spread into the engine struts. This action is intended to address the identified unsafe condition.
To prevent flammable fluid in the upper or rear pylon areas from leaking past unsealed areas and onto a hot engine nozzle, which could result in ignition of the fluid, causing an undetected and uncontrollable fire to spread into the engine struts; accomplish the following:
(a) Within 18 months or 3,500 flight cycles after the effective date of this AD, whichever occurs first: Perform a general visual inspection for sealant at the interface of the diagonal brace fitting and the aft bulkhead and at the four bolts common to the interface, in accordance with the Accomplishment Instructions of Boeing Special Attention Service Bulletin 737-54-1039, Revision 1, dated October 10, 2002.
(1) If the findings of the general visual inspection are as described in paragraphs (a)(1)(i) and (a)(1)(ii) of this AD, then no further action is required by this AD.
(i) The seal is continuous or there is evidence of fay seal sqeeze out present.
(ii) The bolts have evidence of sealant squeeze out or a cap seal exists.
(2) The seal is not continuous and there is no evidence of fay seal squeeze out present, before further flight, fillet seal around the interface of the diagonal brace fitting and the aft bulkhead, in accordance with the Accomplishment Instructions of Boeing Special Attention Service Bulletin 737-54-1039, Revision 1, dated October 10, 2002.
(3) If the bolts do not have evidence of sealant squeeze out and no cap seal exists, before further flight, cap seal the four bolts common to the interface, in accordance with the Accomplishment Instructions of Boeing Special Attention Service Bulletin 737-54-1039, Revision 1, dated October 10, 2002.
(b) Actions accomplished before the effective date of this AD per Boeing Special Attention Service Bulletin 737-54-1039, dated June 13, 2002, are acceptable for compliance with the corresponding actions of paragraph (a) of this AD.
(c) In accordance with 14 CFR 39.19, the Manager, Seattle Aircraft Certification Office, FAA, is authorized to approve AMOCs for this AD.
(d) Unless otherwise specified in this AD, the actions shall be done in accordance with Boeing Special Attention Service Bulletin 737-54-1039, Revision 1, dated October 10, 2002. This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-2207. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call (202) 741-6030, or go to: http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html.
