Which instrument indicates the thrust of a gas turbine engine?

Which instrument indicates the thrust of a gas turbine engine?

• A. Exhaust gas temperature indicator
• B. Turbine inlet temperature indicator
• C. Engine pressure ratio indicator
• D. Engine RPM indicator

Answer: (C)

Thrust in a gas turbine engine is best inferred from the pressure produced and carried through the flow, which is captured by the engine pressure ratio indicator. This instrument compares the pressure at the exhaust/nozzle to the pressure at the inlet/compressor discharge. As throttle is increased and more fuel is burned, the pressures rise and the ratio grows, providing a practical indication of how much thrust the engine is producing. Exhaust gas temperature tells you how hot the exhaust is, which relates to fuel flow and combustion efficiency but doesn’t map directly to thrust. Turbine inlet temperature indicates the heat entering the turbine and limits turbine life, not the thrust output itself. Engine RPM shows how fast the engine is spinning, which correlates with thrust only indirectly and can vary with engine configuration and conditions.

Thrust in a gas turbine engine is best inferred from the pressure produced and carried through the flow, which is captured by the engine pressure ratio indicator. This instrument compares the pressure at the exhaust/nozzle to the pressure at the inlet/compressor discharge. As throttle is increased and more fuel is burned, the pressures rise and the ratio grows, providing a practical indication of how much thrust the engine is producing.

Exhaust gas temperature tells you how hot the exhaust is, which relates to fuel flow and combustion efficiency but doesn’t map directly to thrust. Turbine inlet temperature indicates the heat entering the turbine and limits turbine life, not the thrust output itself. Engine RPM shows how fast the engine is spinning, which correlates with thrust only indirectly and can vary with engine configuration and conditions.