What is the speed of sound in the air at 30000 feet?
What is the speed of sound in the air at 30000 feet? For example, the speed of sound at 30,000 feet is about 670 miles per hour, but an aircraft must travel at least 750 miles per hour (Mach 1.12, where Mach 1 equals the speed of sound) for a boom to be heard on the ground.
What is the slowest plane in the world?
Slowest aircraft The MacCready Gossamer Condor is a human-powered aircraft capable of flight as slow as 8 miles per hour (13 km/h). Its successor, the MacCready Gossamer Albatross can fly as slow as 9.23 miles per hour (14.85 km/h).
Has a 747 ever broken the sound barrier?
Aircraft are put through extreme testing during their certification, but such limits are never intended to be actually faced. The 747 -100, for instance, was tested up to Mach 0.99, almost breaking the sound barrier. Other 747s, such as Air Force One, have approached the sound barrier but never crossed it.
Why do we no longer hear sonic booms?
Why don't we ever hear sonic booms any more? Noise abatement regulations halted supersonic flight (by civil aircraft) over U.S. land. The Concorde could still take off and land here because it broke the sound barrier over the ocean, but it's no longer in service.