Patent ID: 7212942

Claim:
An instrument for use with an aircraft having a piston engine, an outside air temperature sensor for detecting an outside ambient air temperature, a manifold pressure sensor operatively coupled to a manifold of the engine for sensing a manifold pressure of the engine, and an altitude sensor for detecting an altitude of the aircraft, the indicator comprising: an outside air temperature input for receiving an electric air temperature signal representing the ambient air temperature outside the aircraft from the outside air temperature sensor; an altitude input for receiving an electric altitude signal representing the altitude of the aircraft from the altitude sensor; a processing resource including memory, wherein engine performance data, including engine power limits, is stored in the memory; an available pressure algorithm executable by the processing resource and stored in the memory, the available pressure algorithm operable to calculate available ambient air pressure based on the received electric air temperature signal, and the received electric altitude signal; and an indicator for displaying engine power available based on the calculated available ambient air pressure and the stored engine power limits.