AD 2011-20-07 Airworthiness Directives; The Boeing Company Model 737-600, -700, -700C, -800, and -900 Series Airplanes

Models named: 737-600, -700, -700C, -800, -900 series. Read the applicability below — it usually turns on serial or part numbers too.

This AD applies to The Boeing Company Model 737-600, -700, -700C, -800, and -900 series airplanes, certificated in any category; as identified in Boeing Alert Service Bulletin 737-28A1201, Revision 1, dated May 28, 2009.

Comply with this AD within the compliance times specified, unless already done. Replacement or Installation (g) Within 60 months after the effective date of this AD, do the actions required in paragraphs (g)(1) and (g)(2) of this AD. (1) Replace the power control relays that are located in the R18, R19, R20, and R21 positions in the P91 and P92 power distribution panels for the fuel boost pumps with new, improved relays, part number KDAG-X4F-001, having a ground fault interrupter (GFI) feature, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 737-28A1201, Revision 1, dated May 28, 2009, except as provided in paragraphs (h) and (i) of this AD. (2) Replace the power control relays that are located in the R54 and R55 positions in the P91 and P92 power distribution panels for the fuel override pumps, in accordance with the actions required in paragraph (g)(2)(i) or (g)(2)(ii) of this AD. (i) Replace with new, improved relays, part number KDAG-X4F-001, having a GFI feature, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 737-28A1201, Revision 1, dated May 28, 2009, except as provided in paragraphs (h) and (i) of this AD. (ii) Install and maintain TDG Aerospace universal fault interrupters (UFIs) in accordance with a method approved by the Manager, Seattle Aircraft Certification Office, FAA. Note 1: Boeing Alert Service Bulletin 737-28A1201, Revision 1, dated May 28, 2009, refers to Honeywell Service Bulletin 1151932-24-61 and Honeywell Service Bulletin 1151934-24-62, both Revision 5, both dated May 25, 2009, as additional sources of guidance for replacement of the power control relays in the P91 and P92 power distribution panels. Note 2: Guidance on installing TDG Aerospace universal fault interrupters (UFIs) can be found in Supplemental Type Certificate ST02076LA. (h) Where Boeing Alert Service Bulletin 737-28A1201, Revision 1, dated May 28, 2009, specifies accomplishing actions in the P91 and P92 power distribution panels while those panels are installed on the airplane, this AD does not require that the panels are on the airplane while the actions are accomplished. This AD allows the actions on the P91 and P92 panels to be accomplished while those panels are removed from the airplane. Note 3: Section 24-21-21, “Power Distribution Panel,” of the Practices and Procedures section of the Boeing 737-600-700-800-900 Aircraft Maintenance Manual may be used as an additional source of guidance on removing and reinstalling the P91 and P92 power distribution panels. (i) Where Note (a) in Figures 1 and 2 of the Accomplishment Instructions of Boeing Alert Service Bulletin 737-28A1201, Revision 1, dated May 28, 2009, specifies procedures for marking the part numbers of the panels, this AD does not require a specific method for marking. Operators are allowed to use any industry-accepted method. Credit for Actions Accomplished in Accordance With Previous Service Information (j) Actions done before the effective date of this AD in accordance with Boeing Alert Service Bulletin 737-28A1201, dated February 19, 2007, are acceptable for compliance with the requirements of paragraphs (g)(1) and (g)(2)(i) of this AD, provided that Revision 5 of Honeywell Service Bulletins 1151932-24-61 and 1151934-24-62, both dated May 25, 2009, were used as an additional source of guidance. Alternative Methods of Compliance (AMOCs) (k)(1) The Manager, Seattle Aircraft Certification Office (ACO), FAA, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19. In accordance with 14 CFR 39.19, send your request to your principal inspector or local Flight Standards District Office, as appropriate. If sending information directly to the manager of the ACO, send it to the attention of the person identified in the Related Information section of this AD. Information may be e-mailed to: 9-ANM-Seattle-ACO-AMOC-Requests@faa.gov. (2) Before using any approved AMOC, notify your Principal Maintenance Inspector or Principal Avionics Inspector, as appropriate, or lacking a principal inspector, your local Flight Standards District Office. Related Information (l) For more information about this AD, contact Georgios Roussos, Aerospace Engineer, Systems and Equipment Branch, ANM-130S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; phone: 425-917-6482; fax: 425-917-6590; e-mail: georgios.roussos@faa.gov. Material Incorporated by Reference (m) You must use Boeing Alert Service Bulletin 737-28A1201, Revision 1, dated May 28, 2009, to do the actions required by this AD, unless the AD specifies otherwise. (1) The Director of the Federal Register previously approved the incorporation by reference of this service information on September 22, 2010 (75 FR 50859, August 18, 2010). (2) For Boeing service information identified in this AD, contact Boeing Commercial Airplanes, Attention: Data & Services Management, P.O. Box 3707, MC 2H-65, Seattle, Washington 98124-2207; telephone 206-544-5000, extension 1, fax 206-766-5680; e-mail me.boecom@boeing.com; Internet https://www.myboeingfleet.com. (3) You may review copies of the service information at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington. For information on the availability of this material at the FAA, call 425-227-1221. (4) You may also review copies of the service information that is incorporated by reference at the National Archives and Records Administration (NARA). For information on the availability of this material at an NARA facility, call 202-741-6030, or go to http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html. Issued in Renton, Washington on September 20, 2011. Ali Bahrami, Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. 2011-24746 Filed 9-29-11; 8:45 am] BILLING CODE 4910-13-P

This AD was prompted by fuel system reviews conducted by the manufacturer. We are issuing this AD to prevent pump housing burn-through due to electrical arcing, which could create a potential ignition source inside a fuel tank. This condition, in combination with flammable fuel vapors, could result in a fuel tank explosion and consequent loss of the airplane.