# AD 80-01-04: Cylinder Holddown Flange Assemblies - Type: Airworthiness directive - Status: Current - Products: Continental Motors IO-520-A, IO-520-B, IO-520-BA, IO-520-BB, IO-520-C, IO-520-CB, IO-520-D, IO-520-E, IO-520-F, IO-520-J, IO-520-K, IO-520-L and 35 more - Effective: January 25, 1980 - Superseded by: Nothing supersedes this AD - Product type: Engine - Amendment: 39-3647 - Registered aircraft: 14,256 may be affected, by airframe or engine model (OpenAirDocs) - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/9FEF5307506CEE328625684000615D72.0001 - DRS record last changed: May 30, 2024 - Page: https://openairdocs.org/ad/80-01-04 ## The airworthiness directive 80-01-04 TELEDYNE CONTINENTAL MOTORS: Amendment 39-3647. Applies to Continental IO-520 and TSIO-520 series engines incorporating cylinder assemblies which have been rebarrelled by Airmotive Engineering Corporation. Compliance is required within the next 50 hours time in service after the effective date of this AD, unless already accomplished, except aircraft may be flown in accordance with FAR 21.197 to a base where the maintenance required by this AD may be performed. To prevent failure of cylinder holddown flanges, accomplish the following: Inspect to determine if Airmotive Engineering Corporation rebarreled cylinders, Part Numbers AE-C- 631397 T.T., AE-C-639272 T.T., and AE-C-639274 T.T., are installed. If installed, inspect cylinders for .050 inch minimum corner radius in the area spot faced for installation of holddown nuts. Airmotive Engineering Corporation Service Alert dated September 28, 1979, covers this also. Replace all cylinders found without the proper radius. The cylinder part numbers are marked on the flat area of the cylinder holddown flanges on the intake valve side. These cylinder assemblies may have been installed during overhaul or unscheduled maintenance. Airmotive Engineering Corporation Service Alert dated September 28, 1979, pertains to and provides instructions for accomplishing the intent of this AD. The manufacturer's procedures identified and described in this directive are incorporated herein and made a part hereof pursuant to 5 U.S.C. 552(a)(1). All persons affected by this directive who have not already received these documents from the manufacturer may obtain copies upon request to Airmotive Engineering Corporation, 9131 Directors Row, Dallas, Texas 75247. These documents may also be examined at Office of the Regional Counsel, Southwest Region, Federal Aviation Administration, 4400 Blue Mound Road, Fort Worth, Texas. Equivalent means of compliance with the modification prescribed by this AD may be approved by the Chief, Engineering and Manufacturing Branch, Flight Standards Division, Southwest Region, Federal Aviation Administration, Post Office Box 1689, Fort Worth, Texas 76101. This amendment becomes effective January 25, 1980. ## Affected data sheets (2) (OpenAirDocs) The type certificate data sheets whose models the AD names. - [TCDS E8CE](https://openairdocs.org/tcds/E8CE): Continental Aerospace Technologies, Inc.; names 30 of 31 models: TSIO-520-BB, TSIO-520-B, TSIO-520-P, TSIO-520-R, TSIO-520-AF, TSIO-520-M, TSIO-520-J, TSIO-520-A… - [TCDS E5CE](https://openairdocs.org/tcds/E5CE): Continental Aerospace Technologies, Inc.; names 17 of 18 models: IO-520-NB, IO-520-BA, IO-520-A, IO-520-B, IO-520-P, IO-520-C, IO-520-L, IO-520-N… ## 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: 14,256 (0 by airframe model, 14,256 by engine model) - Makers: Cessna 7,278, Beech 6,053, Bellanca 469, Piper 194, Raytheon 69, Aero Commander 62, Navion 43, Mooney 15, Meyers Industries 11, Ryan 10 Models with the most aircraft: - [Continental IO-520 series](https://openairdocs.org/engine/continental-io-520-series): 9,486 aircraft (engine model) - [Continental TSIO-520 series](https://openairdocs.org/engine/continental-tsio-520-series): 4,064 aircraft (engine model) - [Continental IO-520-D](https://openairdocs.org/engine/continental-io-520-d): 95 aircraft (engine model) - [Continental IO-520-F](https://openairdocs.org/engine/continental-io-520-f): 80 aircraft (engine model) - [Continental TSIO-520-M](https://openairdocs.org/engine/continental-tsio-520-m): 60 aircraft (engine model) - [Continental TSIO-520-NB](https://openairdocs.org/engine/continental-tsio-520-nb): 52 aircraft (engine model) - [TCM Cont TSIO-520 series](https://openairdocs.org/engine/tcm-cont-tsio-520-series): 49 aircraft (engine model) - [Lycoming IO-520 series](https://openairdocs.org/engine/lycoming-io-520-series): 49 aircraft (engine model) - [Continental IO-520-BB](https://openairdocs.org/engine/continental-io-520-bb): 44 aircraft (engine model) - [Continental TSIO-520-UB](https://openairdocs.org/engine/continental-tsio-520-ub): 27 aircraft (engine model) - [Continental IO-520-BA](https://openairdocs.org/engine/continental-io-520-ba): 25 aircraft (engine model) - [Continental TSIO-520-R](https://openairdocs.org/engine/continental-tsio-520-r): 22 aircraft (engine model) - [Continental TSIO-520-WB](https://openairdocs.org/engine/continental-tsio-520-wb): 19 aircraft (engine model) - [Continental TSIO-520-C](https://openairdocs.org/engine/continental-tsio-520-c): 17 aircraft (engine model) - [Continental IO-520-B](https://openairdocs.org/engine/continental-io-520-b): 16 aircraft (engine model) - [Continental TSIO-520-P](https://openairdocs.org/engine/continental-tsio-520-p): 12 aircraft (engine model) - [Continental IO-520-L](https://openairdocs.org/engine/continental-io-520-l): 11 aircraft (engine model) - [Continental TSIO-520-H](https://openairdocs.org/engine/continental-tsio-520-h): 11 aircraft (engine model) - [Continental TSIO-520-N](https://openairdocs.org/engine/continental-tsio-520-n): 11 aircraft (engine model) - [Continental TSIO-520-VB](https://openairdocs.org/engine/continental-tsio-520-vb): 11 aircraft (engine model) All 44 models: https://openairdocs.org/ad/80-01-04/models.md Every aircraft: https://openairdocs.org/ad/80-01-04/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.