The FAA gave the plane special call letters: N234MM--the N denotes a plane, and the MM is short of Mickey Mouse. All three planes had the same designation.
Walt had his own seat on the Gulfstream, with an altimeter and air speed indicator on the wall next to the seat, and a telephone direct to the pilot. Walt used the planes for checking out the available acreage in Florida for a theme park. After construction began, it ferried Disney executives back and forth, and was later used for promotional tours for new Disney movies and for theme park promotions. It was nicknamed "The Mouse." Walt contributed to the plane's interior design, and his wife, Lillian assisted in selecting materials and colors.
In a 1978 WED-Way publication is the following information about the Gulfstream (Grumman) now at Walt Disney World: "By 1978, after 14 1/2 years, the plane had logged 4,305,000 miles. That's 12,300 hours in the air, on 5,960 flights. The longest flight was from Burbank to Portland, ME, at 2,700 miles. The plane's maximum time in the air was 8 hours, 33 min."