# AD 73-05-01: Connecting Rod Bearing Assemblies - Type: Airworthiness directive - Status: Current - Products: Lycoming Engines IVO-540-A1A, TIVO-540-A2A, TVO-540-A1A, VO-540-A1A, VO-540-A2A, VO-540-B1A, VO-540-B1B, VO-540-B1B3, VO-540-B1C, VO-540-B1D, VO-540-B1E, VO-540-B1F and 12 more - Effective: July 9, 1974 - Superseded by: Nothing supersedes this AD - Product type: Engine - Amendment: 39-1889 - Registered aircraft: 119 may be affected, by airframe or engine model (OpenAirDocs) - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/3DC77BFA3264218C86256E120055B22E.0001 - DRS record last changed: May 30, 2024 - Page: https://openairdocs.org/ad/73-05-01 ## The airworthiness directive 73-05-01 AVCO LYCOMING: Amendment 39-1595 as amended by Amendment 39-1843 is further amended by Amendment 39-1889. Applies to VO-540 Series engines beginning with S/N 101-43 thru 2299-43, IVO-540 series engines beginning with S/N 101-60 thru 150-60, TVO-540 Series engines beginning with S/N 101-53 thru 103-53 and TIVO-540 Series engines beginning with S/N 101-57 thru 163-57 and all similar series engines overhauled (also known as remanufactured) by Lycoming before January 2, 1974 except the following Serial Numbers: RL-376-43, RL-483-43, RL-693-43, RL-695-43, RL-1091-43, RL-1205-43, RL-1429-43, RL- 1753-43, RL-1960-43, RL-2017-43, RL-2032-43, RL-2125-43, RL-2139-43, RL-2244-43, RL-2245-43 and RL-2275-43. Compliance required as indicated after the effective date of this AD, unless already accomplished or unless higher crush bearing P/N LW13212 has been installed in accordance with Lycoming Service Bulletins No. 303E or 303F. To prevent failures of P/N 71947, P/N 73174, P/N75548 and P/N LW10776 connecting rod assemblies and P/N 77450 connecting rod assembly with P/N 75547 connecting rod bearing installed in accordance with Lycoming Service Bulletins No. 303B, 303C or 303D, accomplish the following: a. Engines with connecting rod assemblies that have accumulated 400 hours or more in service since new or overhaul must have the connecting rod assemblies replaced with new connecting rod assembly, P/N LW13422 and new connecting rod bearing P/N LW13212, within the next 50 hours in service. b. Engines that have connecting rod assemblies with less than 400 hours in service must have the connecting rod assemblies replaced with new connecting rod assembly, P/N LW13422 and new connecting rod bearing, P/N LW13212 prior to 450 hours in service. c. Engines that have been modified in accordance with Lycoming Service Bulletins No. 303B, 303C or 303D must comply with items (a) or (b) above, except that the P/N 77450 connecting rod, free of any galling maybe reused with P/N LW12596 connecting rod bolts and identified as assembly number LW13422. NOTE: Lycoming Service Bulletin No. 371A applies to this subject. Amendment 39-1595 superseded AD 65-13-07 and became effective February 28, 1973. Amendment 39-1843 was effective May 17, 1974. This Amendment 39-1889 is effective July 9, 1974. ## Affected data sheets (3) (OpenAirDocs) The type certificate data sheets whose models the AD names. - [TCDS E-304](https://openairdocs.org/tcds/E-304): Lycoming Engines; names 21 of 21 models: VO-540-B2G, VO-540-B2A, VO-540-B2D, VO-540-B1B3, VO-540-B1D, VO-540-B1C, VO-540-B1A, VO-540-A2A… - [TCDS 1E14](https://openairdocs.org/tcds/1E14): Lycoming Engines; names 2 of 2 models: TIVO-540-A2A, TVO-540-A1A - [TCDS E11EA](https://openairdocs.org/tcds/E11EA): Lycoming Engines; names 1 of 1 models: IVO-540-A1A ## 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: 119 (0 by airframe model, 119 by engine model) - Makers: Hiller 62, Bell 44, Piper 6, Brantly 2, Texas Helicopter 2, Anthony L R/Anthony D J 1, Cessna 1, Hiller-Rogerson Helicopter 1 Models with the most aircraft: - [Lycoming VO-540 series](https://openairdocs.org/engine/lycoming-vo-540-series): 110 aircraft (engine model) - [Lycoming VO-540-C2A](https://openairdocs.org/engine/lycoming-vo-540-c2a): 6 aircraft (engine model) - [Lycoming VO-540-B1B3](https://openairdocs.org/engine/lycoming-vo-540-b1b3): 3 aircraft (engine model) All 4 models: https://openairdocs.org/ad/73-05-01/models.md Every aircraft: https://openairdocs.org/ad/73-05-01/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.