AD 80-25-02 R2
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| engine | Lycoming Engines | O-235 | AVCO LYCOMING Model O-235 Series Engines |
| engine | Lycoming Engines | O-235-A | AVCO LYCOMING Model O-235 Series Engines |
| engine | Lycoming Engines | O-235-AP | AVCO LYCOMING Model O-235 Series Engines |
| engine | Lycoming Engines | O-235-B | AVCO LYCOMING Model O-235 Series Engines |
| engine | Lycoming Engines | O-235-BP-C | AVCO LYCOMING Model O-235 Series Engines |
| engine | Lycoming Engines | O-235-C1 | AVCO LYCOMING Model O-235 Series Engines |
| engine | Lycoming Engines | O-235-C1A | AVCO LYCOMING Model O-235 Series Engines |
| engine | Lycoming Engines | O-235-C1B | AVCO LYCOMING Model O-235 Series Engines |
| engine | Lycoming Engines | O-235-C1C | AVCO LYCOMING Model O-235 Series Engines |
| engine | Lycoming Engines | O-235-C2A | AVCO LYCOMING Model O-235 Series Engines |
Unsafe Condition
Failures of engine pushrods can cause rough engine operation and power loss.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Remove and inspect all eight pushrods for loose ball ends, bulging, splitting, and measure length (not less than 11 17/32 inches). Set valve clearances if conditions are satisfactory. Replace damaged or undersized pushrods. Conduct 25-hour repetitive inspections of valve tappet clearances, and inspect pushrods if clearance increases more than 0.015 inch. Discontinue inspections after installing P/N 73806 pushrods with specified codes.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Prior to further flight and within 25 hours in service after the effective date of this AD and every 25 hours thereafter.
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Affected Aircraft
AVCO Lycoming Model O-235 series engines with serial numbers L-12500-15 thru L-20676-15, all remanufactured engines shipped between Dec 10, 1976, and Nov 8, 1979, and engines with pushrods replaced between Dec 10, 1976, and Nov 24, 1980. Excluded: engines with pushrods P/N 73806, revision K or later, or codes T-T, -85, or # as per SB 453.
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
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