"I think I'd prefer a conventional jet."

The two men estimated the speed of the unknown aircraft to be at the very least three times that of any conventional jet known to them.

The air is then burnt much like in a conventional jet.

So was a new chemical fuel, five times as powerful as the best of conventional jet fuels.

But such a feat was impossible for a conventional jet.

Like a conventional jet, it has fuel and luggage storage beneath the passenger compartment.

"When the wings are extended, it flies as a conventional jet," Tom explained.

The Embraer planes will seat 100 passengers, twice as many as conventional regional jets, and have a range of 2,000 miles.

I think they can grab market share in the future with a low-cost conventional jet versus the Sonic Cruiser.

At low altitude they work like conventional jets, switching to rocket power on the edge of space.