Lycoming O-320 — Airworthiness Directives & known issues
The Lycoming O-320 is installed on 28,818 registered aircraft. These are the Airworthiness Directives that apply to the engine family — whichever airframe it’s bolted to.
Engine ADs for the Lycoming O-320
- one-timeAD 04-14477 — Airworthiness Directives; Lycoming Engines (Formerly Textron Lycoming), Direct-Drive Reciprocating Engines; Correction
This document makes corrections to Airworthiness Directive (AD) 2004-10-14, applicable to Lycoming Engines (formerly Textron Lycoming), direct-drive reciprocating engines that was published in the Federal Register on May 21, 2004 (69 FR 29210). Some corrections to engine models h…
Exact applicability (by engine serial and installed parts) and compliance come from the aircraft’s engine logs.
Known issues on the O-320
Certain Lycoming crankshaft and connecting-rod part numbers were subject to ADs after fatigue failures. Confirm the crankshaft/rod P/Ns and ship dates against the applicable ADs — this is the highest-consequence engine item.
Lycoming cams and lifters are prone to corrosion pitting and spalling on engines flown infrequently — a common mid-life teardown driver. Oil-filter cutting and low iron in oil analysis are reassuring; look for filter inspections and oil analysis in the records.
Lycoming exhaust valves and guides build up deposits and stick, especially on lower-time or infrequently flown engines — a bent-pushrod and rough-start cause. Look for the recurring valve-guide 'wobble' check (Lycoming SB 388) and any valve/guide work.
Tailplate reads a tail number’s logbooks — engine ADs matched to compliance, time since overhaul vs TBO, and the whole records picture.
Look up a tail number →Applicability is derived from the FAA directive corpus and is advisory, not a legal airworthiness determination.