Enable the "Invincibility" option. Take off, but stay on the ground with the landing gear down. Activate the afterburners to "drive" at over 4500 mph.
Hold [Option] and click on "Briefing". Alternatively, hold [Option] and select "Tour Of Duty" from the "Pilot" menu. Then, hold [Option] and click on "Go To Next Mission".
Hold [Option] and select "Tour Of Duty" from the "Missions" menu. A prompt with two fields for mission number and aircraft will appear. Enter one of the following case-sensitive aircraft codes to use that aircraft in the corresponding mission. Note: In order for this cheat to work, the selected mission must already contain the aircraft that is chosen. Alternatively, type fly:[aircraft code]-[aircraft number] as a call sign. For example fly:MG21-00 or fly:B727-00.