# AD 82-06-12: Main Landing Gear Struts - Type: Airworthiness directive - Status: Current - Products: Air Tractor AT-300, AT-301, AT-302, AT-400 and AT-400A - Effective: March 25, 1982 - Superseded by: Nothing supersedes this AD - Product type: Aircraft, Small airplane - Amendment: 39-4350 - Registered aircraft: 135 may be affected, by airframe or engine model (OpenAirDocs) - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/6AA75A378314C8C3862569AF0076741F.0001 - DRS record last changed: May 30, 2024 - Page: https://openairdocs.org/ad/82-06-12 ## The airworthiness directive 82-06-12 AIR TRACTOR: Amendment 39-4350. Applies to Models AT-300 (S/Ns 300-0001 through 300-9999); AT-301 (S/Ns 301-0001 through 301-9999); AT-302 (S/Ns 302-0001 through 302-9999); AT-400 (S/Ns 400-0244 through 400-9999); and AT-400A (S/Ns 400A-0397 through 400A-9999) airplanes certified in any category and equipped with 1-inch-thick (P/N 40007-2 or P/N 40058-1) main landing gear struts. COMPLIANCE: Required as indicated, unless already accomplished. To prevent possible failure of the P/N 40007-2 or P/N 40058-1 main landing gear struts accomplish the following: (a) Models AT-300 and AT-301 airplanes: (1) On struts having exceeded, or upon accumulating, 1,000 hours time-in- service or 5,000 landings, whichever occurs first, within 20 hours time-in-service or 100 landings, whichever occurs first, after the effective date of this AD and thereafter at intervals of 100 hours time-in-service or 500 landings, whichever occurs first, inspect and replace as necessary the landing gear struts in accordance with paragraph (c). (2) On struts having exceeded, or upon accumulating, 2,000 hours time-in- service or 7,500 landings, whichever occurs first, prior to further flight, replace the struts with new struts of the same part number. (b) Models AT-302, AT-400 and AT-400A airplanes: (1) On struts having exceeded, or upon accumulating, 600 hours time-in- service or 3,000 landings, whichever occurs first, within 20 hours time-in-service or 100 landings, whichever occurs first, after the effective date of this AD and thereafter at intervals of 100 hours time-in-service or 500 landings, whichever occurs first, inspect the struts and replace as necessary in accordance with paragraph (c). (2) On struts having exceeded, or upon accumulating, 1,200 hours time-in- service, or 6,000 landings, whichever occurs first, prior to further flight, replace the struts with new struts of the same part number. (c) Remove the left and right outboard fuselage clamp blocks. Remove all minor corrosion on both main landing gears by sandblasting. Inspect both main landing gears using dye penetrant or magnetic particle inspection procedures with special attention in the areas of strut contact with the clamp blocks. Replace all parts which are damaged, cracked, or have severe corrosion pitting with new parts of the same part number before further flight. All struts returned to service must be painted. (d) The aircraft hours and landings may be used as the time-in-service or landings on the struts if time-in-service or landings on the struts cannot be established by the airplane maintenance records. (e) A special flight permit may be issued in accordance with FAR 21.197 to allow flight of the aircraft to a location where this AD can be accomplished. (f) An equivalent method of compliance with this AD may be used when approved by the Chief, Aircraft Certification Division, Federal Aviation Administration, 4400 Blue Mound Road, Fort Worth, Texas 76101. Snow Engineering Company Service Letter No. 45, dated November 1, 1981, covers the subject matter of this AD. Compliance with this Service Letter within the last 100 hours time-in-service or 500 landings, whichever comes first, satisfies the initial inspection requirement of paragraphs (a) and (b) of this AD. This amendment becomes effective on March 25, 1982. ## Affected data sheets (1) (OpenAirDocs) The type certificate data sheets whose models the AD names. - [TCDS A9SW](https://openairdocs.org/tcds/A9SW): Air Tractor Inc.; names 5 of 6 models: AT-301, AT-400, AT-300, AT-302, AT-400A ## Registered aircraft it may apply to (OpenAirDocs) Matched by airframe and engine model; the AD's applicability may narrow it by serial number, part number or equipment. - Aircraft: 135 (135 by airframe model, 0 by engine model) - Makers: Air Tractor 135 Models with the most aircraft: - [Air Tractor AT-301](https://openairdocs.org/model/air-tractor-at-301): 83 aircraft (airframe model) - [Air Tractor AT-400](https://openairdocs.org/model/air-tractor-at-400): 30 aircraft (airframe model) - [Air Tractor AT-400A](https://openairdocs.org/model/air-tractor-at-400a): 19 aircraft (airframe model) - [Air Tractor AT-300](https://openairdocs.org/model/air-tractor-at-300): 2 aircraft (airframe model) - [Air Tractor AT-302](https://openairdocs.org/model/air-tractor-at-302): 1 aircraft (airframe model) All 5 models: https://openairdocs.org/ad/82-06-12/models.md Every aircraft: https://openairdocs.org/ad/82-06-12/aircraft.md Its text cites no advisory circulars or STCs. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.