# AD 76-13-07: Fork Bolts - Type: Airworthiness directive - Status: Current - Products: Cessna 401, 401A, 401B, 402, 402A, 402B, 411, 411A, 414, 414A, 421, 421A and 2 more - Effective: July 7, 1976 - Superseded by: Nothing supersedes this AD - Product type: Aircraft, Small airplane - Amendment: 39-2656 - Registered aircraft: 1,494 may be affected, by airframe or engine model (OpenAirDocs) - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/8893164EAD12C08C86256A340066B289.0001 - DRS record last changed: May 30, 2024 - Page: https://openairdocs.org/ad/76-13-07 ## The airworthiness directive 76-13-07 CESSNA: Amendment 39-2656. Applies to Models 401, 402, 411, 414 and 421 Series Airplanes. Compliance: Required as indicated, unless already accomplished. To prevent failure of the fork bolt located at the aft end of the main landing gear retraction system torque tube connecting the torque tube to the outboard push/pull tube, accomplish the following: A) Within 200 hours' time in service on those airplanes having 1,800 or more hours' time in service or prior to 2,000 hours' time in service on those airplanes having less than 1,800 hours' time in service, and at each subsequent 2,000 hours' time in service thereafter, replace right and left 1/2-inch diameter P/Ns 0843518-1, 0843518-2, 0843500-35, 0843500-54, 5243518-1 and 5243518-3 fork bolts with new P/N 5243518-3 or FAA-approved superseding part number fork bolts on the airplanes specified below except airplanes on which P/N 5141052-1 fork bolts have been installed as field replacements: 401 - 401-0001 thru 401B0053 402 - 402-0001 thru 4-2B0035 411 - All Serials 414 - 414-0001 thru 414-0098 421 - 421-0001 thru 421A0158 B) Within 200 hours' time in service on those airplanes having 4,800 or more hours' time in service or prior to 5,000 hours' time in service on those airplanes having less than 4,800 hours' time in service, and at each subsequent 5,000 hours' time in service thereafter, replace right and left 5/8-inch diameter P/N 5141052-1 fork bolts with new P/N 5141052-1 or FAA-approved superseding part number fork bolts on the airplanes specified below or any lower airplane serial numbers on which these fork bolts have been installed as field replacements. 401 - 401B0054 and on 401 - 402B0036 and on 414 - 414-0099 and on 421 - 421B0001 and on C) Fork bolt life limits set by this AD may be extended 25 hours, up to 2,025 hours for 1/2-inch diameter fork bolts and 5,025 hours for 5/8-inch diameter fork bolts, to allow replacement at regular scheduled maintenance or inspections. D) Aircraft may be flown in accordance with FAR 21.197 to a base where this AD may be accomplished. E) Any equivalent method of compliance with this AD must be approved by the Chief, Engineering and Manufacturing Branch, FAA, Central Region. Cessna Service Letter ME75-23 or later approved revisions refers to this subject. This amendment becomes effective July 7, 1976. ## Affected data sheets (1) (OpenAirDocs) The type certificate data sheets whose models the AD names. - [TCDS A7CE](https://openairdocs.org/tcds/A7CE): Textron Aviation Inc.; names 14 of 16 models: 421C, 402B, 411A, 414, 402, 421B, 421A, 411… ## 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: 1,494 (1,494 by airframe model, 0 by engine model) - Makers: Cessna 1,494 Models with the most aircraft: - [Cessna 421C](https://openairdocs.org/model/cessna-421c): 496 aircraft (airframe model) - [Cessna 414A](https://openairdocs.org/model/cessna-414a): 363 aircraft (airframe model) - [Cessna 414](https://openairdocs.org/model/cessna-414): 242 aircraft (airframe model) - [Cessna 421B](https://openairdocs.org/model/cessna-421b): 225 aircraft (airframe model) - [Cessna 402B](https://openairdocs.org/model/cessna-402b): 49 aircraft (airframe model) - [Cessna 421](https://openairdocs.org/model/cessna-421): 28 aircraft (airframe model) - [Cessna 401](https://openairdocs.org/model/cessna-401): 21 aircraft (airframe model) - [Cessna 421A](https://openairdocs.org/model/cessna-421a): 20 aircraft (airframe model) - [Cessna 401A](https://openairdocs.org/model/cessna-401a): 15 aircraft (airframe model) - [Cessna 401B](https://openairdocs.org/model/cessna-401b): 15 aircraft (airframe model) - [Cessna 402](https://openairdocs.org/model/cessna-402): 7 aircraft (airframe model) - [Cessna 411](https://openairdocs.org/model/cessna-411): 6 aircraft (airframe model) - [Cessna 411A](https://openairdocs.org/model/cessna-411a): 4 aircraft (airframe model) - [Cessna 402A](https://openairdocs.org/model/cessna-402a): 3 aircraft (airframe model) All 15 models: https://openairdocs.org/ad/76-13-07/models.md Every aircraft: https://openairdocs.org/ad/76-13-07/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.