Question id 425 - Aircraft General Knowledge - Airframe, Systems, Powerplant - ATPL - Airline Transport Pilot license

A Greater Value Than Atmospheric Pressure When The Engine Is Running.
A lower value than atmospheric pressure when the engine is running.
A value equal to the QFE when the engine is at full power on the ground.
Zero On The Ground When The Engine Is Stopped.

Training tests and timed exam simulations ATPL - Airline Transport Pilot license