Air Force One

One of two 747s in the presidential fleet

The radio call sign for aircraft used to transport the president of the United States.

Any aircraft used to carry the president is referred to as Air Force One.

The presidential offices on board

At present it usually refers to one of two specially configured Boeing 747-200s, although there are other smaller aircraft in the presidential fleet.

The two 747s are equipped with state-of-the-art communications systems, a stateroom and executive conference rooms, accommodation for the press and private quarters for the president and the first family.

Both aircraft are designed to operate as independently as possible from ground support should the need arise.

They are fitted with self-contained baggage loading equipment, front and rear stairs, a medical centre and the capability for in-flight refuelling.

The US Vice President's aircraft, used by Al Gore for election campaign visits, is known as Air Force Two.