The United States Air Force operates two highly specialized aircraft for presidential use: the VC-25A, known as Air Force One, and the E-4B Nightwatch, often referred to as the "Doomsday" aircraft. Both are modified Boeing 747-200s designed to enable the President and senior government officials to maintain command over national affairs from the air.
The VC-25A, commonly called Air Force One when the President is aboard, serves as more than just a transport vehicle. It functions as a flying command center with capabilities such as midair refueling and advanced secure communications. According to the White House, it can operate during an attack on the United States: "Capable of refueling midair, Air Force One has unlimited range and can carry the President wherever he or she needs to travel." The aircraft's systems are hardened against electromagnetic pulses.
Air Force One will soon be replaced by two Boeing 747-8Is designated VC-25B. Despite being behind schedule, Boeing is working on these replacements under a $3.9 billion contract but expects significant financial losses due to fixed pricing.