AD 92-07-14

92-07-14 AIR TRACTOR INC: Amendment 39-8210. Docket No. 91-CE-55-AD.

Applicability: Models AT-300, AT-301, and AT-302 airplanes (serial numbers (S/N) 300-0001 through 301-0688); Model AT-400 airplanes (S/N 400-0244 through 400-0415; and Model AT-400A airplanes (all S/N), certificated in any category.

Compliance: Required within the next 90 calendar days after the effective date of this AD, unless already accomplished, and thereafter at intervals not to exceed 12 calendar months.

To prevent failure of the wing structure that could result in loss of control of the airplane, accomplish the following:

(a) Remove the inspection plates on the lower side of the wing leading edge skin, and visually inspect the upper and lower aluminum spar caps from the centerline to outboard end for corrosion using a flashlight and mirror.

(1) If corrosion is found that is equal to or less than the criteria in Air Tractor Inc. Service Letter No. 90, dated May 6, 1991, prior tofurther flight, repair in accordance with the instructions in Air Tractor Inc. Service Letter No. 90, dated May 6, 1991.

(2) If corrosion is found that is more than the criteria in Air Tractor Inc. Service Letter No. 90, dated May 6, 1991, prior to further flight, replace the wing spar cap in accordance with the applicable maintenance manual.

(b) Special flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate the airplane to a location where the requirements of this AD can be accomplished.

(c) An alternative method of compliance or adjustment of the initial or repetitive compliance times that provides an equivalent level of safety may be approved by the Manager, Airplane Certification Office, FAA, Southwest Region, 4400 Blue Mound Road, Fort Worth, Texas 76193. The request should be forwarded through an appropriate FAA Maintenance Inspector, who may add comments and then send it to the Manager, Fort Worth Airplane Certification Office.

(d) The inspections and possible repair required by this AD shall be done in accordance with Air Tractor Inc. Service Letter No. 90, dated May 6, 1991. This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR Part 51. Copies may be obtained from Air Tractor Inc., P.O. Box 485, Olney, Texas 76374-0150. Copies may be inspected at the FAA, Central Region, Office of the Assistant Chief Counsel, Room 1558, 601 E. 12th Street, Kansas City, Missouri, or at the Office of the Federal Register, 1100 L Street, NW, Room 8401, Washington, DC.

(e) This amendment becomes effective on May 8, 1992.