During airplane operations beyond 36 hours without engine oil tank servicing, when must the engine oil level be checked?

During airplane operations beyond 36 hours without engine oil tank servicing, when must the engine oil level be checked?

• A. Before every engine start
• B. After every engine shutdown
• C. At takeoff
• D. In flight

Answer: (B)

Oil level readings are reliable only after the engine is shut down and the oil has cooled and settled. When the engine is running, oil is hot, pressurized, and circulating, so the level shown on a dipstick or in the tank can be misleading. For operations extending beyond 36 hours since the last oil servicing, the procedure requires checking the oil level after shutdown to confirm there’s enough oil for the next flight leg and to catch any consumption or leakage early. Checking before start, in flight, or at takeoff wouldn’t provide a valid, repeatable measurement and isn’t the intended practice.

Oil level readings are reliable only after the engine is shut down and the oil has cooled and settled. When the engine is running, oil is hot, pressurized, and circulating, so the level shown on a dipstick or in the tank can be misleading. For operations extending beyond 36 hours since the last oil servicing, the procedure requires checking the oil level after shutdown to confirm there’s enough oil for the next flight leg and to catch any consumption or leakage early. Checking before start, in flight, or at takeoff wouldn’t provide a valid, repeatable measurement and isn’t the intended practice.