Air Force One

Air Force One is the air traffic control call sign of any United States Air Force aircraft carrying the President of the United States. While these aircraft are referred to as "Air Force One" only while the president is on board, the term is commonly used to describe either of the two aircraft normally used and maintained by the U.S. Air Force solely for the president.
When the president needs to fly to locations that have runways too short for the VC-25A, a Boeing C-32 is used instead; the Lockheed C-140 Jetstar was also used in this role, notably by Ronald Reagan.[citation needed]
An Air Force aircraft carrying the Vice President of the United States is designated as Air Force Two.

E-9A

E-9AThe E-9A is used as a surveillance platform to ensure the Gulf of Mexico waters are clear of civilian boaters and aircraft during live missile launches and other hazardous military activities. Its capabilities are airborne sea surveillance, telemetry recording and relay. The E-9A provides support for air-to-air weapons system evaluation, development and operational testing at Tyndall Air Force Base, Fla.