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How do you start an airplane without APU?
The general process of a non-APU flight is keeping ground power and ground air conditioning hooked up to the airplane for pre-flight activity and boarding. Once the airplane is closed up the ground crew will coordinate with you to provide air via the ground start cart and you’ll start one or both of your engines.
Can airplane fly without APU?
Aircraft are allowed in general to fly without an APU. Exceptions are flights with two-engined aircraft and long routes over water or terrain without an alternate airport – so called ETOPS flights.
How does a APU start?
APUs are like small jet engines, small enough to be started electrically. So you would use the power of the battery or an electric ground power cart to spin up the APU by its electric starter motor, and then introduce fuel into it once its spinning fast enough, just like a jet engine is started.
What is an aircraft auxiliary power unit (APU)?
An aircraft auxiliary power unit serves as an additional energy source normally used to start one of the main engines on an airliner or business jet. The APU is equipped with an extra electrical generator to create enough power to operate onboard lighting, galley electrics and cockpit avionics, usually while the aircraft is parked at the gate.
What was the first Boeing aircraft with an APU?
The 727 was the first Boeing to be APU-equipped. Today, APUs can be found in medium-size and larger civil and military jets, some turboprop aircraft and a handful of military fighters.
Is the APU an extra jet engine?
But calling the APU an extra jet engine is not accurate because the turbine exhaust from the APU is vented overboard. A jet engine would be used to propel the aircraft forward. The earliest APUs could be found on the B-29 Superfortress, looking essentially like a motorcycle engine installed inside the fuselage.
What happens to the APU during takeoff and landing?
In most cases, the APU is shut down before takeoff and reignited when the aircraft clears the runway after landing. While most of an APU’s active service life occurs as the aircraft sits on the ground, in some instances the APU is used as an emergency electrical power source while the aircraft is airborne.