# AD 68-08-08: Hydraulic Valve - Type: Airworthiness directive - Status: Current - Products: Lycoming Engines IGSO-480-A1A6, IGSO-480-A1B6, IGSO-480-A1C6, IGSO-480-A1F6, IVO-360-A1A, IVO-540-A1A, TIVO-540-A2A, TVO-435-A1A, TVO-435-B1A, TVO-435-B1B, TVO-435-C1A, TVO-435-D1A and 35 more - Effective: May 19, 1968 - Superseded by: Nothing supersedes this AD - Product type: Engine - Amendment: 39-584 - Registered aircraft: 343 may be affected, by airframe or engine model (OpenAirDocs) - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/D0AA1FF030A927FE8625682A00513FFB.0001 - DRS record last changed: May 30, 2024 - Page: https://openairdocs.org/ad/68-08-08 ## The airworthiness directive 68-08-08 LYCOMING: Amendment 39-584. Applies to VO, IVO-360 Series: VO, TVO-435 Series; IGSO-480 Series excluding models IGSO-480-A1D6, -A1E6, -A1G6; VO, IVO, TIVO-540 Series engines which incorporate the P/N 76289 hydraulic valve lifter. Compliance required as indicated. To prevent further valve failures replace hydraulic lifter P/N 76289 with P/N 78289 at the time in service specified below: (a) TVO-435, VO-540, IVO-540, and TIVO-540 Series engines shall comply within 50 hours' time in service after the effective date of this AD. (b) VO-360, VO-435, and IGSO-480 Series engines with less than 600 hours' time in service on P/N 76289 as of the effective date of this AD, shall comply prior to the accumulation of 650 hours' time in service on P/N 76289. (c) VO-360, IVO-360, VO-345, and IGSO-480 Series engines with 600 or more hours' time in service on P/N 76289 as of the effective date of this AD shall comply within the next 50 hours' time in service. (NOTE: Lycoming Service Bulletin No. 314A provides serial numbers of new and factory remanufactured engines which have the P/N 76289 hydraulic valve lifter.) This amendment effective May 19, 1968. ## Affected data sheets (7) (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 1E13](https://openairdocs.org/tcds/1E13): Lycoming Engines; names 9 of 11 models: TVO-435-D1B, TVO-435-A1A, TVO-435-E1A, TVO-435-C1A, TVO-435-B1B, TVO-435-B1A (O-435-25A), TVO-435-D1A, TVO-435-F1A… - [TCDS E-279](https://openairdocs.org/tcds/E-279): Lycoming Engines; names 7 of 7 models: VO-435-A1A (O-435-21), VO-435-A1F, VO-435-A1C (O-435-23; -23A; -23B; -23C), VO-435-A1E, VO-435-A1D (O-435-6A), VO-435-B1A, VO-435-A1B (O-435-6) - [TCDS 1E1](https://openairdocs.org/tcds/1E1): Lycoming Engines; names 4 of 4 models: IVO-360-A1A, VO-360-A1A, VO-360-B1A, VO-360-A1B - [TCDS E-284](https://openairdocs.org/tcds/E-284): Lycoming Engines; names 4 of 23 models: IGSO-480-A1A6 (O-480-3), IGSO-480-A1B6, IGSO-480-A1C6, IGSO-480-A1F6 - [TCDS 1E14](https://openairdocs.org/tcds/1E14): Lycoming Engines; names 1 of 2 models: TIVO-540-A2A - [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: 343 (0 by airframe model, 343 by engine model) - Makers: Bell 220, Hiller 75, Continental Copters 11, Texas Helicopter 10, Piper 6, Brantly 4, Hiller-Osborn 2, Anthony L R/Anthony D J 1, Bell-Carson 1, Bell-Continental Copters 1 Models with the most aircraft: - [Lycoming VO-435 series](https://openairdocs.org/engine/lycoming-vo-435-series): 191 aircraft (engine model) - [Lycoming VO-540 series](https://openairdocs.org/engine/lycoming-vo-540-series): 110 aircraft (engine model) - [Lycoming VO-435-A1F](https://openairdocs.org/engine/lycoming-vo-435-a1f): 15 aircraft (engine model) - [Lycoming VO-435-B1A](https://openairdocs.org/engine/lycoming-vo-435-b1a): 6 aircraft (engine model) - [Lycoming VO-540-C2A](https://openairdocs.org/engine/lycoming-vo-540-c2a): 6 aircraft (engine model) - [Lycoming VO-435-A1D](https://openairdocs.org/engine/lycoming-vo-435-a1d): 3 aircraft (engine model) - [Lycoming VO-540-B1B3](https://openairdocs.org/engine/lycoming-vo-540-b1b3): 3 aircraft (engine model) - [Lycoming IVO-360-A1A](https://openairdocs.org/engine/lycoming-ivo-360-a1a): 2 aircraft (engine model) - [Lycoming TVO-435-B1A](https://openairdocs.org/engine/lycoming-tvo-435-b1a): 2 aircraft (engine model) - [Lycoming TVO-435-D1A](https://openairdocs.org/engine/lycoming-tvo-435-d1a): 2 aircraft (engine model) - [Lycoming TVO-435-A1A](https://openairdocs.org/engine/lycoming-tvo-435-a1a): 1 aircraft (engine model) - [Lycoming TVO-435-F1A](https://openairdocs.org/engine/lycoming-tvo-435-f1a): 1 aircraft (engine model) - [Lycoming TVO-435-G1A](https://openairdocs.org/engine/lycoming-tvo-435-g1a): 1 aircraft (engine model) All 14 models: https://openairdocs.org/ad/68-08-08/models.md Every aircraft: https://openairdocs.org/ad/68-08-08/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.