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Propeller planes are unfortunately limited to subsonic speeds. A propeller will spin its blades (using an engine), creating lower pressure in front and higher pressure in the back, pushing the plane forward. Propeller planes can reach upwards of 870 km/h (540 mph) but are limited to being subsonic, because of the effect the of shock waves on the propeller.

Jet engines, however, have no such limitations. By mixing air with the fuel, a combustion is created that pushes on every side of the engine except, of course, the hole in the back. This creates more push in the front which thrusts the jet plane forward. Jet planes are not limited to subsonic speeds, and can go as fast as 12,000 km/h (7,000 mph).