If the oil pressure is 50 PSI and the OIL PRESS LO light does not illuminate, the pilot should:

• A. Increase thrust on the affected engine
• B. Reduce thrust lever power to the affected engine
• C. Land immediately
• D. Check other indicators

Answer: (C)

Oil pressure warnings rely on both the pressure reading and a dedicated warning light. If you see a reading around 50 psi but the OIL PRESS LO light does not illuminate, you’ve got a potential mismatch between the gauge and the warning circuit. In this CTSys context, such a discrepancy is treated as a high‑risk situation because a warning system fault could hide an actual oil‑pressure problem. The safest course is to land immediately to verify engine lubrication and diagnose the warning system on the ground. If readings and indicators are then confirmed normal, you can resume normal flight with continued monitoring.