AD 2006-23-14 Airworthiness Directives; Air Tractor, Inc. Models AT-502, AT-502A, AT-502B, AT-602, AT-802, and AT-802A Airplanes

This AD affects the following airplane models and serial numbers that are certificated in any category:   Model Serial Nos. (1) AT-502 and AT-502B 502/502B-0003 through 502/502B-2600. (2) AT-502A 502A-0003 through 502A-2582. (3) AT-602 602-0337 through 602-1138. (4) AT-802 and AT-802A 802/802A-0001 through 802/802A-0215.

To address this problem, you must do the following:   Actions Compliance Procedures (1) Inspect visually the rudder and vertical hinge attachment for loose fasteners; and inspect the rudder or vertical fin skins, spars, hinges or brackets for cracks and/or corrosion Initially inspect upon reaching 3,500 hours time-in-service (TIS), or within the next 100 hours TIS after December 21, 2006 (the effective date of this AD), whichever occurs later, unless already done. Thereafter, repetitively inspect 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, dated August 14, 2005, revised May 17, 2006. (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 is the terminating action for the repetitive inspections required by this AD Follow Snow Engineering Co. Service Letter #247, dated August 14, 2005, revised May 17, 2006, 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 Upon accumulating 5,000 hours TIS or within the next 100 hours TIS after the effective date of this AD, whichever occurs later, unless already done. The installation of the external doubler at the upper rudder hinge required by paragraph (e)(2)(ii) or (e)(3) of this AD is the terminating action for the repetitive inspections required by this AD Follow Snow Engineering Co. Service Letter #247, dated August 14, 2005, revised May 17, 2006, 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 December 21, 2006 (the effective date of this AD) Not Applicable. Alternative Methods of Compliance (AMOCs) (f) The Manager, Fort Worth Aircraft Certification Office, FAA, ATTN: Andrew McAnaul, Aerospace Engineer, ASW-150 (c/o MIDO-43), 10100 Reunion Place, Suite 650, San Antonio, Texas 78216; telephone: (210) 308-3365; fax: (210) 308-3370, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19. Material Incorporated by Reference (g) You must use Snow Engineering Co. Service Letter #247, dated August 14, 2005, revised May 17, 2006; 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 this service information under 5 U.S.C. 552(a) and 1 CFR part 51. (2) For service information identified in this AD, contact Air Tractor, Inc., P.O. Box 485, Olney, Texas 76374; telephone: (940) 564-5616; fax: (940) 564-5612. (3) 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, on November 3, 2006. James E. Jackson, Acting Manager, Small Airplane Directorate, Aircraft Certification Service. [FR Doc. E6-19153 Filed 11-15-06; 8:45 am] BILLING CODE 4910-13-P

This AD results from two reports (one Model AT-602 airplane and one Model AT-802A airplane) of in-flight rudder separations at the upper attach hinge area and other reports of Models AT-502B, AT-602, and AT-802/802A airplanes with loose hinges, skin cracks, or signs of repairs to the affected area. We are issuing this AD to detect and correct loose fasteners; any cracks in the rudder or vertical fin skins, spars, hinges or brackets; and/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.