Description
An air start unit (also known as a « start cart ») is a device used to start an aircraft’s engines when it is not equipped with an on-board APU or the APU is not operational. There are three primary types of these devices that exist currently: a stored air cart, a gas turbine based unit, and a diesel engine driven screw compressor unit. All three devices create a source of low pressure, high volume air to start the aircraft engines. Typically one or two hoses are connected to these units, with the largest aircraft engines requiring three.