Air Force One is the call sign of any aircraft operated by the US Air Force while the president of the United States is onboard. It often, but not necessarily, refers to one of two Boeing VC-25 aircraft (heavily-modified 747-200Bs).
Air Force One is the air-traffic-control callsign used by any us-air-force (USAF) aircraft carrying the President of the United States of America. A USAF aircraft carrying the Vice President of the United States of America uses the similar callsign Air Force Two.
The aircraft used as Air Force One nowadays is almost always one of two Boeing VC-25A jets (a modified version of the boeing-747-200 produced specifically for the purpose of transporting the President), but other aircraft can also fill this role. The VC-25As are scheduled to be replaced by 2024 with two VC-25Bs (specially-modified 747-8s). In common parlance, the VC-25s are frequently referred to simply as "Air Force One", but this is not, strictly-speaking, accurate; as the United States has only one president, at most one of the VC-25s can be Air Force One at any given time, and, as noted above, an aircraft other than a VC-25 can serve as Air Force One if the situation calls for it. Between 1959 and 1990, the aircraft usually used for Air Force One was one of a number of Boeing VC-137s (modified versions of the boeing-707); prior to this, a number of propeller-driven aircraft were used as presidential transports (the callsign "Air Force One" was not introduced until 1959), with perhaps the best-known being two Lockheed VC-121s (a lockheed-constellation variant) named Columbine II and III.
When flying into backcountry airports too small to safely accommodate a VC-25, the presidential aircraft of choice is a Boeing C-32 (a modified boeing-757); the C-32s are also the primary choice for Air Force Two (having replaced the VC-135s, which were - until they were retired in 1998 - the primary aircraft for both Air Force One and Air Force Two).
A non-USAF aircraft with the President of the United States onboard does not use the "Air Force One" callsign, but, rather, a different callsign ending in "One" (to signify that the president is onboard), depending on its operator:
- An aircraft (typically a helicopter) operated by the United States Marine Corps (USMC) uses the callsign marine-one.
- An aircraft (typically a helicopter) operated by the United States Army (USA) uses the callsign Army One; this was last used in 1976.
- An aircraft operated by the United States Navy (USN) uses the callsign Navy One; this has occurred only once, in May 2003.
- An aircraft operated by the United States Coast Guard (USCG) would use the callsign Coast Guard One, but this has never occurred.
- A commercial or private flight uses the callsign Executive One; this has occurred only once, in December 1973.
A non-USAF aircraft carrying the Vice President of the United States is, likewise, designated Marine Two, Army Two, Navy Two, Coast Guard Two, or Executive Two, depending on its operator.