Which statement about Engine Pressure Ratio (EPR) usage is true?

Which statement about Engine Pressure Ratio (EPR) usage is true?

• A. Engine pressure ratio (EPR) is used to set takeoff power on many aircraft.
• B. Engine pressure ratio measures engine oil pressure.
• C. EPR is used for navigation.
• D. EPR measures cabin pressure.

Answer: (A)

Engine Pressure Ratio is a thrust-related indicator that compares the pressure in the engine’s exhaust to the pressure at the engine inlet. As throttle increases, the pressure difference grows, and the engine produces more thrust. Because of this direct link to thrust, pilots use a target EPR to set takeoff power on many aircraft, providing a practical way to achieve consistent takeoff performance across engines and conditions. EPR isn’t a measurement of oil pressure, isn’t used for navigation, and doesn’t indicate cabin pressure. Each of those systems has its own separate indicators and purposes, while EPR specifically reflects the engine’s thrust capability through the pressure ratio.

Engine Pressure Ratio is a thrust-related indicator that compares the pressure in the engine’s exhaust to the pressure at the engine inlet. As throttle increases, the pressure difference grows, and the engine produces more thrust. Because of this direct link to thrust, pilots use a target EPR to set takeoff power on many aircraft, providing a practical way to achieve consistent takeoff performance across engines and conditions.

EPR isn’t a measurement of oil pressure, isn’t used for navigation, and doesn’t indicate cabin pressure. Each of those systems has its own separate indicators and purposes, while EPR specifically reflects the engine’s thrust capability through the pressure ratio.