AD 91-21-01 R1
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| engine | Lycoming Engines | TIO-540-S1AD | Textron Lycoming Model TIO-540-S1AD Engines |
Unsafe Condition
Cracking or distortion of engine exhaust system flanges, V-band coupling, and pipes could result in engine compartment fire and smoke entering the cabin with possible loss to the aircraft.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Install specific exhaust system kits (05K21125, 05K21503, 05K19650-S) per SBs 484 and 499A. Inspect exhaust system for damage, wear, clearances, and fastener torque at intervals not exceeding 100 hours TIS. Repair or replace damaged parts before further flight.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Within 25 hours time in service (TIS) after the effective date of this AD, and thereafter at intervals not to exceed 100 hours TIS.
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
Textron Lycoming Model TIO-540-S1AD engines installed on but not limited to Piper PA-32 series aircraft.
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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