AD 2008-21-08 Airworthiness Directives; Air Tractor, Inc. Models AT-402, AT-402A, and AT-402B Airplanes

Models named: AT-402, AT-402A, AT-402B. Read the applicability below — it usually turns on serial or part numbers too.

This AD applies to Models AT-402, AT-402A, and AT-402B airplanes, serial numbers 0694 through 1176, that are certificated in any category.

To address this problem, you must do the following, unless already done:   Actions Compliance Procedures (1) Inspect visually the rudder and vertical fin hinge attachment for loose fasteners; and inspect the rudder or vertical fin skins, spars, hinges, and brackets for cracks and/or corrosion Initially inspect when the airplane reaches a total of 3,500 hours time-in-service (TIS) or within the next 100 hours TIS after November 20, 2008 (the effective date of this AD), whichever occurs later. Thereafter, repetitively inspect at intervals not to exceed every 100 hours TIS. Installation of the external doubler at the upper rudder hinge required by paragraph (e)(2)(ii) or (e)(3) of this AD is terminating action for the repetitive inspections required by this AD Follow Snow Engineering Co. Service Letter #247, revised June 2, 2008. (2) If you find any damage as a result of any inspection required by paragraph (e)(1) of this AD, you must: (i) Replace any damaged parts with new parts; and (ii) Do the installation of the external doubler at the upper rudder hinge. Before further flight after any inspection required by paragraph (e)(1) of this AD where you find any damaged parts. The installation of the external doubler at the upper rudder hinge required by paragraph (e)(2)(ii) or (e)(3) of this AD terminates the repetitive inspections required by this AD Follow Snow Engineering Co. Service Letter #247, revised June 2, 2008; and Snow Engineering Co. Process Specification Number 145, dated December 6, 1991. (3) Do the installation of the external doubler at the upper rudder hinge When the airplane reaches a total of 5,000 hours TIS after November 20, 2008 (the effective date of this AD) or within the next 100 hours TIS after November 20, 2008 (the effective date of this AD), whichever occurs later. The installation of the external doubler at the upper rudder hinge required by paragraph (e)(2)(ii) or (e)(3) of this AD terminates the repetitive inspections required by this AD Follow Snow Engineering Co. Service Letter #247, revised June 2, 2008; and Snow Engineering Co. Process Specification Number 145, dated December 6, 1991. (4) Do not install any rudder without the external doubler at the upper rudder hinge required by paragraph (e)(3) of this AD As of November 20, 2008 (the effective date of this AD) Not Applicable. Alternative Methods of Compliance (AMOCs) (f) The Manager, Fort Worth Airplane Certification Office, 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: Andrew McAnaul, Aerospace Engineer, ASW-150 (c/o MIDO-43), 10100 Reunion Place, Suite 650, San Antonio, Texas 78216; telephone: (210) 308-3365; facsimile: (210) 308-3370. 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 Snow Engineering Co. Service Letter #247, revised June 2, 2008; and Snow Engineering Co. Process Specification Number 145, dated December 6, 1991, 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 Snow Engineering Co. Service Letter #247, revised June 2, 2008, under 5 U.S.C. 552(a) and 1 CFR part 51. (2) On December 21, 2006 (71 FR 66661, November 16, 2006), the Director of the Federal Register approved the incorporation by reference of Snow Engineering Co. Process Specification Number 145, dated December 6, 1991. (3) For service information identified in this AD, contact Air Tractor, Inc., P.O. Box 485, Olney, Texas 76374; telephone: (940) 564-5616; facsimile: (940) 564-5612; E-mail: parts@airtractor.com; Web site: http://www.airtractor.com. (4) You may review copies at the FAA, Central Region, Office of the Regional Counsel, 901 Locust, Kansas City, Missouri 64106; 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. Issued in Kansas City, Missouri. Kim Smith, Manager, Small Airplane Directorate, Aircraft Certification Service. [FR Doc. E8-24137 Filed 10-15-08; 8:45 am] BILLING CODE 4910-13-P

This AD results from a report of a Model AT-402 airplane with a loose upper rudder hinge caused by fatigue. We are issuing this AD to detect and correct loose fasteners; any cracks in the rudder or vertical fin skins, spars, hinges, or brackets; or corrosion of the rudder and vertical fin hinge attaching structure. Hinge failure adversely affects ability to control yaw and has led to the rudder folding over in flight. This condition could allow the rudder to contact the elevator and affect ability to control pitch with consequent loss of control.