barometric pressure control

barometric pressure control (BPC)

A device in the engine control system that regulates the fuel flow rate to meet the engine requirements dictated by the altitude of the aircraft. It consists of an evacuated capsule subject to nacelle pressure, which operates a lever system balanced by fuel pressure acting on a small diaphragm. The lever also carries a valve that controls the pump stroke through the pump servoline. The varying pump stroke varies the amount of fuel flowing into the engine.