AD 63-23-02
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| engine | Lycoming Engines | O-320-A1A | LYCOMING Model O-320 Engines |
| engine | Lycoming Engines | O-320-A1B | LYCOMING Model O-320 Engines |
| engine | Lycoming Engines | O-320-A2A | LYCOMING Model O-320 Engines |
| engine | Lycoming Engines | O-320-A2B | LYCOMING Model O-320 Engines |
| engine | Lycoming Engines | O-320-A2C | LYCOMING Model O-320 Engines |
| engine | Lycoming Engines | O-320-A3A | LYCOMING Model O-320 Engines |
| engine | Lycoming Engines | O-320-A3B | LYCOMING Model O-320 Engines |
| engine | Lycoming Engines | O-320-A3C | LYCOMING Model O-320 Engines |
| engine | Lycoming Engines | O-320-B1A | LYCOMING Model O-320 Engines |
| engine | Lycoming Engines | O-320-B1B | LYCOMING Model O-320 Engines |
Unsafe Condition
Exhaust valve stem and camshaft assembly (P/N 68769) may fail due to excessive wear, leading to engine failure.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Inspect and replace exhaust valves and guides as necessary per Lycoming Service Bulletin No. 293B or an approved alternative method.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Within the next 100 hours' time in service and every 300 or 500 hours' time in service thereafter, depending on engine usage and time since last inspection.
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
Lycoming Engines Model O-320 with exhaust valve stem diameter 7/16" and camshaft assembly P/N 68769, including specific models: O-320-A1A, O-320-A1B, O-320-A2A, O-320-A2B, O-320-A2C, O-320-A3A, O-320-A3B, O-320-A3C, and others as listed.
AI-generated summary from the source AD text. Verify against the official source before acting.
Source: Official FAA Source ↗
Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
This site is not affiliated with or endorsed by the FAA. Always verify with official sources.