Alan Mulally shows off the Boeing Sonic Cruiser

But Boeing thinks that speed is what their customers want.

Alan Mullaly of Boeing, introduced the company's new Sonic Cruiser at the Paris Air Show last year.

The Sonic Cruiser will travel faster than today's passenger jets.

According to Boeing, it will give a 15-20% reduction in flight time.

Boeing's vice president of the Commercial Airplanes Group, Randy Baseler, explains the idea behind the new plane.

"On a long flight it might be such where you've had to use two or three airplanes to do that whole flight exchange over that route, you might be able to do it with one less - that's a big savings for an airline," Mr Baseler says.

Boeing insists people want to fly from smaller airports direct to where they want to go, faster than they can do so at the moment.

Space

But John Leahy, chief commercial officer of Airbus, disagrees.

He argues that the airlines have to be able to provide space and economics for the passenger.

Cramped cabins: A thing of the past?

The Airbus A380 is a dazzling demonstration of how the European company thinks much of the world's flying will be done, starting in 2006.

It is designed to carry at least 550 passengers, and to give passengers a completely new experience. There is space everywhere in this new giant aircraft.

The mock-up of the new plane has a shop where even economy class passengers can stand up, move around, and buy duty free goods.

This is an industry which transforms the world.

It lives in a business cycle that is so expensive to start that the planes of 30 years ago still shape the way we travel, and the way the airlines work.

Long term plans

The two great aircraft makers are preparing to spend as much as $10bn readying their business strategy for the next 40 or 50 years.

There is a very, very strong likelihood that they both will prosper

Daniel Solon

Both planes may sell, but one may be quite wrong for the 21st century.

But veteran air travel consultant Daniel Solon of Avmark International in London is optimistic. He has watched the industry for many years.

"I think there is a very, very strong likelihood that they both will prosper with their respective strategies," he says.

It will be 20 years before we know for sure whether speedy Boeing or super Jumbo Airbus have got their business plans right and profitable.

And by then, it will be time to start planning the next great leap forward in air travel.