Up and away

How do you convert a standard jet fighter for vertical take-off? British
Aerospace—renamed BAE Systems—of Farnborough is patenting (GB 2 341
155) a scheme to modify jets as they are manufactured or refitted. The plane
will have ordinary fixed exhausts at the rear—like the Eurofighter. But it
will also have a retractable S-shaped pipe stored inside the fuselage which can
channel the backward thrust downwards. In level flight, the duct is stowed away
so that it creates no aerodynamic drag. Sounds like a tricky transition . . .