AD 64-16-05
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| engine | Lycoming Engines | HIO-360-B1A | LYCOMING Model O-320, O-340, O-360 and O-540 Series Engines and IO-320-B1A, IO-360-A1A, -B1B, HIO-360-B1A, -B1B and IO-540-C-B5 Engines |
| engine | Lycoming Engines | HIO-360-B1B | LYCOMING Model O-320, O-340, O-360 and O-540 Series Engines and IO-320-B1A, IO-360-A1A, -B1B, HIO-360-B1A, -B1B and IO-540-C-B5 Engines |
| engine | Lycoming Engines | IO-320-B1A | LYCOMING Model O-320, O-340, O-360 and O-540 Series Engines and IO-320-B1A, IO-360-A1A, -B1B, HIO-360-B1A, -B1B and IO-540-C-B5 Engines |
| engine | Lycoming Engines | IO-360-A1A | LYCOMING Model O-320, O-340, O-360 and O-540 Series Engines and IO-320-B1A, IO-360-A1A, -B1B, HIO-360-B1A, -B1B and IO-540-C-B5 Engines |
| engine | Lycoming Engines | IO-360-B1B | LYCOMING Model O-320, O-340, O-360 and O-540 Series Engines and IO-320-B1A, IO-360-A1A, -B1B, HIO-360-B1A, -B1B and IO-540-C-B5 Engines |
| engine | Lycoming Engines | IO-540-C1B5 | LYCOMING Model O-320, O-340, O-360 and O-540 Series Engines and IO-320-B1A, IO-360-A1A, -B1B, HIO-360-B1A, -B1B and IO-540-C-B5 Engines |
| engine | Lycoming Engines | O-320-A1A | LYCOMING Model O-320, O-340, O-360 and O-540 Series Engines and IO-320-B1A, IO-360-A1A, -B1B, HIO-360-B1A, -B1B and IO-540-C-B5 Engines |
| engine | Lycoming Engines | O-320-A1B | LYCOMING Model O-320, O-340, O-360 and O-540 Series Engines and IO-320-B1A, IO-360-A1A, -B1B, HIO-360-B1A, -B1B and IO-540-C-B5 Engines |
| engine | Lycoming Engines | O-320-A2A | LYCOMING Model O-320, O-340, O-360 and O-540 Series Engines and IO-320-B1A, IO-360-A1A, -B1B, HIO-360-B1A, -B1B and IO-540-C-B5 Engines |
| engine | Lycoming Engines | O-320-A2B | LYCOMING Model O-320, O-340, O-360 and O-540 Series Engines and IO-320-B1A, IO-360-A1A, -B1B, HIO-360-B1A, -B1B and IO-540-C-B5 Engines |
Unsafe Condition
Oil seal failure in AC light weight fuel pumps could drain engine oil overboard.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Modify AC pumps with specified part numbers per Lycoming Service Bulletin No. 298.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
within 25 hours' time in service after the effective date of this AD unless already accomplished
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
Lycoming Engines: O-320, O-340, O-360, O-540 Series Engines with AC Fuel Pumps (AC 5623-467, AC 5656880, AC 6440152, AC 5623466, AC 5656696) and IO-320-B1A, IO-360-A1A, -B1B, HIO-360-B1A, -B1B, IO-540-C-B5 Engines with AC Fuel Pumps, excluding recent production or remanufactured engines listed in SB No. 298.
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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