School Bus 1 is a school bus primarilly used for the transportation of Gallagher Elementary School's Class Presidents. Its name is clearly a pun on Air Force One, the airline used as air transportation for the President of the United States.
One of which has appeared in Operation: P.R.E.S.I.D.E.N.T. and was used to transport the ex-fourth grade president, James "Jimmy" Nixon McGarfield, to city hall for the negotiations with the school board. While the Sector V operatives were trying to get Jimmy to city hall, the Delightful Children From Down the Lane tried to intercept the transportation, sending the Ice Cream Men and an evil robotic clone of Jimmy to do their dirty work along the way. As Numbuh 2 managed to drop the real Jimmy off at City Hall after he fought his robot clone, the other four operatives had brought the bus to a junkyard, destroying it in a trash compactor, along with the Robot Jimmy itself.
It's armed with detatchable stop signs that function as hoverboards and homework released from the back bumper to blind pursuing vehicles, and is capable of air travel. It also seems to have an autopilot, as noted when the President Jimmy robot had opened the driver's door on Numbuh 2, sucking him out of the bus.