Critical altitude

Critical Altitude: The highest altitude which a turbocharged engine can maintain its rated horsepower while operating under standard atmospheric conditions. This altitude is reached when the pressure inside the intake manifold of the engine is equivalent to the outside atmospheric pressure. If the aircraft ascends beyond this altitude, the power of the engine begins to decrease, causing a reduction in performance and speed. The critical altitude is determined based on the engine’s design, including the size of the turbocharger, the compression ratio, and the fuel injection system. It plays a crucial role in determining the aircraft’s operational limitations, including its maximum altitude and range. Pilots must be aware of the critical altitude when planning their flights and adjust accordingly to ensure the aircraft’s safe and efficient operation.