AD 2009-25-02 Airworthiness Directives; Twin Commander Aircraft LLC Models 690, 690A, and 690B Airplanes

Makes named: commander, twin commander. Read the applicability below — it usually turns on serial or part numbers too.

This AD applies to the following airplane models and serial numbers that are certificated in any category:   Models Serial Nos. (S/Ns) 690 All S/Ns 690A All S/Ns except 11195 and 11279. 690B All S/Ns except 11361, 11383, 11527, and 11536.

To address this problem, you must do the following, unless already done:   Actions Compliance Procedures (1) Inspect between the surface of the left-hand (LH) and right-hand (RH) upper wing skins and the engine mount beam support straps for any signs of corrosion and determine the extent of any corrosion found Within the next 150 hours time-in-service after January 8, 2010 (the effective date of this AD) or within the next 12 months after January 8, 2010 (the effective date of this AD), whichever occurs first Follow Twin Commander Aircraft LLC Alert Service Bulletin No. 237, dated May 13, 2005, pages 1 through 14. (2) Install modification access holes in the LH and RH lower wing skins Before further flight after the inspection required in paragraph (e)(1) of this AD Follow the Accomplishment Instructions, steps 1 through 4 and 6 through 9, of Twin Commander Aircraft Corporation Custom Kit No. 150, dated July 8, 1994, as specified in Twin Commander Aircraft LLC Alert Service Bulletin No. 237, dated May 13, 2005. (3) If corrosion damage is found during the inspection required in paragraph (e)(1) of this AD, perform necessary modification Before further flight after the inspection required in paragraph (e)(1) of this AD Follow Twin Commander Aircraft LLC Alert Service Bulletin No. 237, dated May 13, 2005, Part II, Options A, B, or C, on pages 15 through 29 and 31. (4) If corrosion damage is not found during the inspection required in paragraph (e)(1) of this AD, do the upper steel strap replacements Before further flight after the inspection required in paragraph (e)(1) of this AD Follow Twin Commander Aircraft LLC Alert Service Bulletin No. 237, dated May 13, 2005, Part II, Option D, on pages 30 and 31. (5) Install additional wing fasteners on the LH and RH wing Before further flight after the inspection required in paragraph (e)(1) of the AD Follow Gulfstream American Corporation Service Bulletin No. 182, dated March 2, 1981. Note: Although not required by this AD, we highly recommend compliance with Twin Commander Aircraft Corporation Service Bulletin No. 217, Revision No. 1, dated May 26, 1993, Engine Nacelle Firewall Reinforcement; and Twin Commander Aircraft LLC Alert Service Bulletin No. 239, dated February 13, 2006, Outboard Flap—Inboard Hinge Inspection & Reinforcement. Alternative Methods of Compliance (AMOCs) (f) 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. Send information to ATTN: Vince Massey, Aerospace Engineer, FAA, Seattle ACO, 1601 Lind Avenue, SW, Renton, Washington 98057-3356; telephone: (425) 917-6475; fax: (425) 917-6590; email: vince.massey@faa.gov . Before using any approved AMOC on any airplane to which the AMOC applies, notify your appropriate principal inspector (PI) in the FAA Flight Standards District Office (FSDO), or lacking a PI, your local FSDO. Material Incorporated by Reference (g) You must use Twin Commander Aircraft LLC Alert Service Bulletin No. 237, dated May 13, 2005; Twin Commander Aircraft Corporation Custom Kit No. 150, dated July 8, 1994; and Gulfstream American Corporation Service Bulletin No. 182, dated March 2, 1981, 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 Twin Commander Aircraft LLC, 18933—59th Avenue, NE., Arlington, WA 98223, telephone: (360) 435-9797; fax: (360) 435-1112; Internet: http://www.twincommander.com. (3) You may review copies of the service information incorporated by reference for this AD at the FAA, Central Region, Office of the Regional Counsel, 901 Locust, Kansas City, Missouri 64106. For information on the availability of this material at the Central Region, call (816) 329-3768. (4) You may also review copies of the service information incorporated by reference for this AD 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 Kansas City, Missouri, on November 20, 2009. Margaret Kline, Acting Manager, Small Airplane Directorate, Aircraft Certification Service. [FR Doc. E9-28548 Filed 12-3-09; 8:45 am] BILLING CODE 4910-13-P

This AD results from reports that corrosion was found between the mating surfaces of the wing upper skin surface and the engine mount beam support straps. We are issuing this AD to detect and correct corrosion on the engine mount beam support straps and upper wing skins, which could result in failure of the engine mount beam support straps. This failure could lead to loss of the engine and possible loss of control of the airplane.