For live service or support inquiries, call the number that best meets your needs.

APU (Auxiliary Power Unit)

The Auxiliary Power Unit (APU) is a small engine located in the aircraft's tail. It provides power for lighting, air conditioning, and avionics when the main engines are not running, such as during boarding or at the gate.

Related Terms:

Ground handling ,Taxiway ,Pushback ,Cabin pressure
2025 © Business Travel Group LLC Florida FST #ST41395
* The prices shown are in U.S. dollars and are per person based on weekday travel (Monday-Thursday) from the United States including all taxes and fees. The fares will vary based on class of travel, availability, airline and city of departure. Business-Class.com will not identify all travel partners or details to not to compete with retail sales of our partners. Savings up to 60% off are based on un-restricted fares of major airlines and can vary depending on the fare rules. All fares are non-refundable and cannot be exchanged or transferred. Please call us directly to check the most current prices and availability. Other restrictions may apply. All fares are subject to change until ticketed.
* Rates from 0–36% APR. Payment options through Affirm are subject to an eligibility check, may not be available everywhere, and are provided by these lending partners: affirm.com/lenders. Options depend on your purchase amount, and a down payment may be required. For licenses and disclosures, see affirm.com/licenses.