During MIL power on the ground, the nozzle position is within which range?

During MIL power on the ground, the nozzle position is within which range?

• A. 0-20
• B. 50-70
• C. 80-100
• D. 30-40

Answer: (A)

The important idea here is that nozzle position is used to control how much exhaust flow the engine can push out, which directly affects backpressure, thrust, and engine stability. At MIL (military) power on the ground, the nozzle is kept largely closed to maintain sufficient backpressure and stabilize the compressor and turbine inlet conditions. This keeps turbine inlet temperatures and engine stress within safe limits during ground operation, where airflow and ambient conditions don’t demand the higher thrust you’d need in flight or for takeoff. Opening the nozzle more would increase exhaust flow and thrust beyond what’s needed on the ground and could raise temperatures or risk compressor instability during power transitions. As flight power needs rise, the nozzle would open more to match the greater mass flow and thrust requirements.

The important idea here is that nozzle position is used to control how much exhaust flow the engine can push out, which directly affects backpressure, thrust, and engine stability. At MIL (military) power on the ground, the nozzle is kept largely closed to maintain sufficient backpressure and stabilize the compressor and turbine inlet conditions. This keeps turbine inlet temperatures and engine stress within safe limits during ground operation, where airflow and ambient conditions don’t demand the higher thrust you’d need in flight or for takeoff. Opening the nozzle more would increase exhaust flow and thrust beyond what’s needed on the ground and could raise temperatures or risk compressor instability during power transitions. As flight power needs rise, the nozzle would open more to match the greater mass flow and thrust requirements.