Air Force One
Air Force One is the term used to identify any aeroplane on which the President of the United States is flying. It is an official call sign used by air traffic control.
Franklin Roosevelt was the first president to fly Air Force One (designated VC-54A) when he flew to the Yalta Conference aboard a Douglas C-54 Skymaster which was built for presidential use. The Skymaster had a conference room, state room and bathroom and featured a bullet-proof picture window. To accommodate Roosevelt, who used a wheel chair, there was an elevator added to help him enter and exit the plane. Affectionately known as "the Sacred Cow" by journalists the Skymaster was used once by Roosevelt who died in 1945. In 1947, the Spymaster was moved to other flying duties and was retired from service in 1961. The Skymaster was a propeller driven airplane.
During the President Harry Truman's administration a modified Douglas C-118 Liftmaster was selected as Air Force One. The Liftmaster was a military version of the civilian DC-6 airplane and was named Independence to honor Truman's hometown of Independence, Missouri. The Independence featured a pressurized cabin, 24 passenger seats, and the president's quarters had a reclining swivel chair with a full-sized sofa bed. The C-118 Liftmaster, another propeller driven airplane, remained in service until 1953.