# AD 79-10-03 R2: Engine Mounting Bracket Attaching Bolts - Type: Airworthiness directive - Status: Current - Products: Lycoming Engines LO-360-E1A6D, O-320-H2AD and O-360-E1A6D - Effective: July 1, 1980 - Superseded by: Nothing supersedes this AD - Product type: Engine - Amendment: 39-3813 - Registered aircraft: 40,406 may be affected, by airframe or engine model (OpenAirDocs) - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/F3D0446C6BD1CB2A8625682B0054462F.0001 - DRS record last changed: May 30, 2024 - Page: https://openairdocs.org/ad/79-10-03-R2 ## The airworthiness directive 79-10-03 R2 AVCO LYCOMING: Amendment 39-3462 as amended by Amendment 39-3628 is further amended by Amendment 39-3813. Applies to O-360-E1A6D Series engines, Serial Number L-101-77 thru L-347-77, L-352-77 and LO-360-E1A6D Series engines, Serial Number L-101-72 thru L-319-72, L-321-72 thru L-324-72, L-326-72 thru L-339-72, L-341-72 thru L-348-72, L-350-72 installed in the Piper Model PA-44 aircraft, and O-320-H2AD Series engines, Serial Number L-101-76 thru L-5707-76 or any engine remanufactured prior to January 4, 1979, installed in the Cessna Model 172N and Partenavia Model P-66C. Unless already accomplished, compliance required before further flight for O-360-E1A6D/LO-360-E1A6D engines, and within 50 hours after the effective date of this AD for O-320-H2AD model engines. Aircraft may be flown in accordance with FAR 21.197 to a base where the required inspection can be performed. To prevent loss of integrity of the engine to aircraft mounting due to loosening of the engine mounting bracket attaching bolts, inspect the eight part number LW38-2.75 mounting bolts for correct torque. Mounting bolts found to be 200 inch-pounds or less of torque when measured in the tightening direction must be replaced and torqued to 360 inch-pounds. Those mounting bolts found to be less than 360 inch-pounds but greater than 200 inch-pounds must be retorqued to 360 inch-pounds. Lycoming Service Instruction No. 1380, dated 6-22-79, applies to this subject. Upon submission of substantiating data by an owner or operator through an FAA maintenance inspector, the Chief, Engineering & Manufacturing Branch, FAA Eastern Region, May adjust the compliance time specified in this AD. Amendment 39-3462 was effective May 9, 1979. Amendment 39-3628 was effective December 7, 1979. This Amendment 39-3813 is effective July 1, 1980, and was effective immediately for all recipients of the airmail letter dated December 10, 1979, pertaining to this same matter. ## Affected data sheets (2) (OpenAirDocs) The type certificate data sheets whose models the AD names. - [TCDS E-286](https://openairdocs.org/tcds/E-286): Lycoming Engines; names 2 of 72 models: O-360-E1A6D, LO-360-E1A6D - [TCDS E-274](https://openairdocs.org/tcds/E-274): Lycoming Engines; names 1 of 60 models: O-320-H2AD ## 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: 40,406 (0 by airframe model, 40,406 by engine model) - Makers: Piper 17,630, Cessna 11,411, Mooney 1,556, Grumman American Avn. 1,162, Beech 1,147, Bellanca 760, Robinson Helicopter 497, American Champion 321, Champion 297, Gulfstream American 271 Models with the most aircraft: - [Lycoming 0-320 series](https://openairdocs.org/engine/lycoming-0-320-series): 27,061 aircraft (engine model) - [Lycoming O&VO-360 series](https://openairdocs.org/engine/lycoming-o-vo-360-series): 11,930 aircraft (engine model) - [Lycoming O-360 series](https://openairdocs.org/engine/lycoming-o-360-series): 1,023 aircraft (engine model) - [Lycoming O-320 series](https://openairdocs.org/engine/lycoming-o-320-series): 256 aircraft (engine model) - [Lycoming O-320-H2AD](https://openairdocs.org/engine/lycoming-o-320-h2ad): 83 aircraft (engine model) - [Lycoming 0-360 series](https://openairdocs.org/engine/lycoming-0-360-series): 44 aircraft (engine model) - [Lycoming O-360-E1A6D](https://openairdocs.org/engine/lycoming-o-360-e1a6d): 7 aircraft (engine model) - [Aerotec O-320 series](https://openairdocs.org/engine/aerotec-o-320-series): 2 aircraft (engine model) All 8 models: https://openairdocs.org/ad/79-10-03-R2/models.md Every aircraft: https://openairdocs.org/ad/79-10-03-R2/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.