http://www.fighter-planes.com/jetmach1.htm http://www.fighter-planes.com/jetmach1.htm According to that page, at 60,000 feet the speed of sound is 1062 km/h, m

http://www.fighter-planes.com/jetmach1.htm http://www.fighter-planes.com/jetmach1.htm According to that page, at 60,000 feet the speed of sound is 1062 km/h, making 3629 km/h approximately mach 3.4.