FAA Aviation Mechanic Powerplant (AMP)Reciprocating EnginesHard
A technician is performing a run-up check on a reciprocating engine and observes that the oil pressure gauge reads zero while the engine is running. The oil temperature gauge is still indicating a normal temperature. Which of the following is the most immediate and critical action the technician should take?
- ACheck the oil level in the engine.
- BImmediately shut down the engine.
- CTap the oil pressure gauge to check for sticking.
- DIncrease engine RPM to see if pressure builds.
Show answer & explanationAnswer & explanation
Correct answer: B. Immediately shut down the engine.
A sudden and sustained loss of oil pressure, even with normal oil temperature, indicates a critical failure in the lubrication system. Continuing to run the engine without lubrication will lead to rapid and catastrophic engine damage. Immediate shutdown is required.
Why the other options are wrong
- A. While checking oil level is part of pre-flight, a zero reading while running indicates a severe issue beyond just low oil, and immediate shutdown is paramount.
- C. Tapping the gauge is a troubleshooting step for a potentially faulty instrument, but a zero reading often indicates a real problem, and the risk of engine damage outweighs the possibility of a false reading.
- D. Increasing RPM without oil pressure will only accelerate engine damage.
Zero Oil Pressure (In-Flight/Run-up)
A critical indication of complete lubrication system failure in a reciprocating engine, requiring immediate engine shutdown.
- Indicates no oil flow to critical engine components.
- Rapid engine failure will occur without lubrication.
- Always treat as a genuine emergency unless proven otherwise.
Memory trick: Zero pressure means zero time, shut it down!