Last month Airbus had an ambitious-looking patent approved by the US authorities for an "ultra-rapid air vehicle and related method of aerial locomotion."

The company will be hoping that someday this hypersonic jet will be a viable travel option which will be able to climb to speeds of Mach 4.5 - that's four and a half times the speed of sound.

PatentYogi has been crunching the numbers, and says that if such a craft was made it would be able to fly from London to New York in one hour - a significant improvement on the three and a half hour flights offered by Concorde.

Airbus estimates that flights from Paris to San Francisco and Los Angeles to Tokyo would take three hours.

The craft uses two turbojets and a rocket motor to take off, it then climbs vertically into the sky until reaching the speed of sound - the plane would then use wing-mounted ramjets to cruise at 100,000 feet.

The company suggests that the plane would be powered by hydrogen - and that it could fit 20 passengers and have both civilian and military uses.