Mr Burbage: "We are able to combine those unique requirements"

But what makes the JSF so special? Lockheed says the key is flexibility.

"The navy demands very good slow-speed flying qualities for handling the aeroplane on and off a ship.

"The marine corp requires vertical take-off and landing, (as does) the Royal Navy," said Tom Burbage, executive vice president and general manager at JSF Project, Lockheed Martin.

"For the first time, we are able to combine those unique requirements."

Rethinking

The JSF programme has forced both Boeing and Lockheed to radically rethink the way they carry out business.

Mr Heinz: "The entire team works... toward a single set of goals"

"What we are doing is developing a virtual single enterprise which is totally integrated across our entire team in such a way that the normal boundaries between a prime contractor and its major suppliers have been obliterated," said Michael Heinz, deputy programme manager, JSF Project, Boeing.

"The entire team works with a single integrated plan with a single set of processes, toward a single set of goals,"

Affordable

Both sides have been told that they must make this an affordable project - not just in development but throughout the time that JSF is in service.

US Defence Secretary Donald Rumsfelt's military spending review is casting a shadow over JSF but Boeing and Lockheed Martin remain confident it'll survive any possible cutbacks.

So now the emphasis switches from Paris to the Pentagon - an announcement's expected in October.