Aviation Mechanic - General, Airframe, and Powerplant › III. Powerplant › Task D. Engine Instrument Systems

AM.III.D.K7

Knowledge

Engine pressure ratio (EPR).

Study note

Get a short, cited explanation of this element written from the FAA handbooks: the core idea, the numbers that matter, common test traps, and a quick self-check.

From the FAA library

Aviation Maintenance Technician Handbook - Airframe p. 10-9
Chapter 10: Aircraft Systems › Pressure Instruments › Engine Pressure Ratio (EPR)
Engine Pressure Ratio (EPR) Turbine engines have their own pressure indication that relates the power being developed by the engine. It is called the engine pressure ratio (EPR) indicator (EPR gauge). This gauge compares the total exhaust pressure ... being developed by the engine. Since the EPR gauge compares two pressures, it is a differential pressure gauge. It is a remote-sensing instrument that receives its input from an engine pressure ratio transmitter or, in digital instrument systems displays…
Pilot Guide: Flight in Icing Conditions p. 26
Chapter 3. ICING EFFECTS, PROTECTION, AND DETECTION › 3-11. EFFECTS OF ICING ON CRITICAL SYSTEMS › e. Engine Pressure Ratio (EPR) Probe (Turbine Engines)
lower end of the windshield to spray deicing fluid onto it and prevent ice from forming. e. Engine Pressure Ratio (EPR) Probe (Turbine Engines) (1) Ice crystals can clog and freeze over turbine EPR probes as well, resulting in unreliable…
Pilot's Handbook of Aeronautical Knowledge p. 7-22
Chapter 7: Aircraft Systems › Turbine Engines › Exhaust Gas Temperature (EGT)
Engine Pressure Ratio (EPR) An engine pressure ratio (EPR) gauge is used ... indicate the power output of a turbojet/turbofan engine. EPR is the ratio of turbine discharge to compressor inlet pressure. Pressure measurements are recorded by probes installed in the engine inlet and at the exhaust. Once collected, the data is sent…