ENVIRONMENTAL CONTROL SYSTEM (ECS) for the B-52 G/H Aircraft - The Boeing B-52 G/H aircraft uses precooled engine bleed air as a source for cabin pressurization and cabin, missile and avionics air conditioning. These systems are controlled by two solid state controllers which also contain built in self test and fault isolation. The ECS regulates the bleed air pressure and flow via an electrical signal from a cooling effect sensor in the avionics air supply. This flow control approach saves engine bleed air by not dumping excessive cold air into the avionics equipment and not over-cooling or overheating the two cabins or missiles. The missile conditioning system mixes cold and warm air to keep the missiles at the required temperature. The system also provides a “go-no-go” signal to the cabin to indicate “temperature readiness” of the missiles. The two cabins are separately temperature controlled through individual temperature selectors and controls.