AD 2020-19-06
Unsafe Condition
The non-conforming idler gear bearing could have also been included in the idler gear assembly (idler gear and bearing), P/N A-20107, or the governor overhaul kit, P/N PL-20233 or PL-20234. The non-conformity of the bearing may cause premature failure of the idler gear bearing. Early symptoms that the idler gear bearing may fail include inability of the governor to hold the selected RPM, hunting, surging, etc.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Replacing an affected governor with a governor that is eligible for installation. The FAA is issuing this AD to prevent failure of the idler gear bearing, which could result in failure of the governor, loss of propeller pitch control, engine and propeller over speed, engine oil contamination, and loss of airplane control.
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Compliance Time
Before further flight
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Affected Aircraft
McCauley Propeller Systems, all models of governors with an idler gear bearing with P/N A-20028 installed, part marking BA 59, or the idler gear assembly (idler gear and bearing), P/N A-20107, or the governor overhaul kit, P/N PL-20233 or PL-20234.
AI-generated summary from the source AD text. Verify against the official source before acting.
Source: Official FAA Source ↗
Retrieved: Apr 4, 2026
Rights: U.S. Government Public Domain
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