AD 76-21-06
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Cessna Aircraft Company | 172M | Airworthiness Directives; CESSNA Models 172M, 172N. 177B and 177RG Airplanes |
| aircraft | Cessna Aircraft Company | 172N | Airworthiness Directives; CESSNA Models 172M, 172N. 177B and 177RG Airplanes |
| aircraft | Cessna Aircraft Company | 177B | Airworthiness Directives; CESSNA Models 172M, 172N. 177B and 177RG Airplanes |
| aircraft | Cessna Aircraft Company | 177RG | Airworthiness Directives; CESSNA Models 172M, 172N. 177B and 177RG Airplanes |
Unsafe Condition
Loss of engine oil due to Model 8406J (S/N 101 thru 1500) or Model 10599A (S/N 101 thru 700) engine oil cooler fluid fitting side.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Before next flight, inspect the engine oil cooler fluid fitting side to determine if it is Model 8406J (S/N 101-1500) or Model 10599A (S/N 101-700). If not, record the inspection and return to service. If it is, replace the cooler with a serviceable one not of those models/serials before further flight.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Before next flight (inspection) and prior to further flight (replacement if required).
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
CESSNA Models 172M (Serial Numbers 17266981-17267584); 172N (specific serial ranges listed); 177B (Serial Numbers 17702450-17702536, 17702538-17702544); 177RG (Serial Numbers 177RG0875-177RG0990, 177RG0992-177RG0995, 0997-1000, 1002, 1004)
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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