There used to be. The presidential yacht:
- The callsign of a civil (non-governmental) vehicle/craft carrying the president is “Executive One”.
- The 89th Airlift Wing is in charge of the logistics of the movement of senior government staff (including the president).
- As the vehicles are prefixed with the name of the branch of the military that operates them (e.g. Marine One is a Marines-operated craft).
- Nelson Rockefeller (yes.. those Rockefellers) was the Vice President for Gerald Ford.
- There is precedent for US presidents to travel on a commercial aircraft flying on a public schedule: In 1973, to “set an example for the rest of the nation during the current energy crisis” and to “demonstrate his confidence in the airlines”, then-President Richard Nixon became the only sitting president to travel on a regularly scheduled commercial airline flight when he flew on a United Airlines DC-10 from Washington Dulles International Airport to Los Angeles International Airport.