Which system would indicate an increase in engine RPM?

• A. Oil Pressure Indicating System
• B. Fuel Flow Indicating System
• C. Engine Speed Indicating System
• D. Engine Temperature Indicating System

Answer: (C)

The Engine Speed Indicating System is specifically designed to monitor and display the RPM (revolutions per minute) of the engine. This system uses various sensors and instruments to measure the rotational speed of the engine's crankshaft or other rotating components, providing a real-time readout of engine performance. An increase in engine RPM signifies that the engine is operating at a higher speed, which is crucial for understanding engine performance, efficiency, and power output during various phases of flight and operation.

The other systems mentioned serve different functions. The Oil Pressure Indicating System monitors the pressure of the oil circulating through the engine, which is important for lubrication but does not directly correlate to engine RPM. The Fuel Flow Indicating System tracks the rate at which fuel is consumed by the engine, which can be affected by RPM but does not directly measure it. Lastly, the Engine Temperature Indicating System assesses the temperature of engine components, which is vital for preventing overheating but is unrelated to RPM measurements. Thus, the Engine Speed Indicating System is the correct choice for indicating changes in engine RPM.