AD 2011-16-06 Airworthiness Directives; The Boeing Company Model 747-400 and -400F Series Airplanes

Models named: 747-400, -400F series. Read the applicability below — it usually turns on serial or part numbers too.

This AD applies to The Boeing Company Model 747-400 and -400F series airplanes, certificated in any category, as identified in Boeing Alert Service Bulletin 747-25A3588, Revision 1, dated April 7, 2011.

Comply with this AD within the compliance times specified, unless already done. Inspection (g) Within 24 months after the effective date of this AD, do the actions specified in paragraph (g)(1) or (g)(2) of this AD, as applicable, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 747-25A3588, Revision 1, dated April 7, 2011. (1) For Group 1 and Group 3 airplanes, as identified in Boeing Alert Service Bulletin 747-25A3588, Revision 1, dated April 7, 2011: Do a general visual inspection of the MEC drip shield to detect cracking and holes, do all applicable repairs, and install the MEC drip shield panel stiffeners and the fiberglass reinforcing overcoat to the MEC drip shield, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 747-25A3588, Revision 1, dated April 7, 2011. Do all applicable repairs before further flight. (2) For Group 2 airplanes, as identified in Boeing Alert Service Bulletin 747-25A3588, Revision 1, dated April 7, 2011: Do a general visual inspection of the MEC drip shield to detect cracking and holes, do all applicable repairs, and install the fiberglass reinforcing overcoat to the MEC drip shield, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 747-25A3588, Revision 1, dated April 7, 2011. Do all applicable repairs before further flight. Credit for Actions Accomplished in Accordance With Previous Service Information (h) Accomplishing the actions required in paragraph (g) of this AD before the effective date of this AD in accordance with Boeing Alert Service Bulletin 747-25A3588, dated July 19, 2010, is considered acceptable for compliance with the corresponding actions specified in this AD. Alternative Methods of Compliance (AMOCs) (i)(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 appropriate principal inspector, or lacking a principal inspector, the manager of the local flight standards district office/certificate holding district office. Related Information (j) For more information about this AD, contact Francis Smith, Aerospace Engineer, Cabin Safety & Environmental Systems Branch, ANM-150S, FAA, Seattle Aircraft Certification Office (ACO), 1601 Lind Avenue, SW., Renton, Washington 98057-3356; phone: 425-917-6596 ; fax: 425-917-6590; e-mail: Francis.Smith@faa.gov . Material Incorporated by Reference (k) You must use Boeing Alert Service Bulletin 747-25A3588, Revision 1, dated April 7, 2011, to do the actions required by this AD, unless the AD specifies otherwise. (1) The Director of the Federal Register approved the incorporation by reference of this service information under 5 U.S.C. 552(a) and 1 CFR part 51. (2) For 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; phone: 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 NARA, 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 July 26, 2011. Ali Bahrami, Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. 2011-19828 Filed 8-4-11; 8:45 am] BILLING CODE 4910-13-P

This AD was prompted by a report of a loss of bus control unit number 1 and generator control units numbers 1 and 2 while the airplane was on the ground, and multiple operator reports of cracked main equipment center (MEC) drip shields. We are issuing this AD to prevent water penetration into the MEC, which could result in the loss of flight critical systems.