AD 65-21-04
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Hartzell Propeller, Inc. | HC-12X20-7 | HARTZELL Models HC-12X20-7 and -8 Propellers |
| aircraft | Hartzell Propeller, Inc. | HC-12X20-8 | HARTZELL Models HC-12X20-7 and -8 Propellers |
Unsafe Condition
Failure of the A-38 propeller bearing
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Required Actions
Inspect and replace as necessary each A-38 bearing per Hartzell Service Bulletin No. 82. Replace A-38 bearings with riveted cages with crimped cage or A-83B bearings with bakelite cage per the same bulletin. Grease the A-38 bearing within 100 hours and every subsequent 100 hours. For propellers unused over two months, grease before flight; over six months, remove, inspect, replace bearings/diaphragms as needed, and grease. Identify modified propellers with a 3/4-inch white spot on the piston face.
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Compliance Time
within the next 100 hours' time in service after the effective date of this AD
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Affected Aircraft
Hartzell Propeller, Inc. Models HC-12X20-7 and -8 Propellers installed on Navion, Navion A, Beech 35, Bellanca, Stinson L-5, and Stinson 108 airplanes
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Source: Official FAA Source ↗
Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
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