DARPA at work on 'Transformer TX', a proper flying car
'Morphing' robo hover-Prius to run on 'ring motors'
Those splendid brainboxes at DARPA, the Pentagon paradigm-punishment powerhouse, have administered what may be the kiss of life or death to a treasured idea - that of the flying car.
True flying cars, as all regular followers of the Reg's coverage will know, remain well beyond humanity's grasp at present. A credible "roadable aeroplane", the Terrafugia Transition, has now flown: there are also various powered paraglider type craft in service which can stow their canopies and drive on the ground.
But these aren't flying cars. The Transition is a light plane which you'll be able to drive on the road. Powered paragliders like the Parajet SkyCar have similar issues.
In both cases, you need a decently long bit of flat open space in which to land and - especially - in which to take off. Both types of machine require expensive time-consuming training for the pilot, and even more training - plus a pricey extra fit of instruments - to fly in clouds or controlled airspace like that found above cities and major airports. Even with full instruments and pilot ratings, they can still be grounded by bad enough weather.
Neither can make vertical landings and takeoffs, nor hover in midair, and both are also very noisy. All this means that operations into and out of built-up areas aren't feasible. The Transition is intended to land or take off at existing small airstrips; the SkyCar and its ilk would perhaps be able to make use of small fields etc. where there weren't too many neighbours, but on the other hand it flies disappointingly slowly.
What you want for a true flying car is something that can hover, which is quiet, which requires no expensive and perishable piloting skills, and which can still be driven on roads. Combine that with an automated high-capacity air traffic system, and you really would be into proper flying car territory.
That's exactly what DARPA are after with their "Transformer (TX) vehicle" programme, for which they have requested an initial $2m of funding in financial year 2010. According to the Pentagon boffins:
Technical areas that will be explored include: hybrid electric drive ducted fan propulsion system, ring motors, energy storage methods such as batteries and ultra capacitors, morphing vehicle bodies, and advanced flight controls and flight management systems.
All this will be applied to produce 1-4 person TX vehicles which can fly for up to two hours "on one tank of fuel", travel on roads, and be operated "by a typical soldier" - eg by someone without training as a pilot.
This would seem to indicate some kind of conventional liquid-fuelled engine as the prime mover, supplying power to an electrical transmission driving ducted fan thrusters. These thrusters would be easily swivelled to provide vertical lift capability or drive the TX forward through the air - perhaps using battery or ultracapacitor power to boost that of the engine for hovering or bursts of speed. Such a propulsion system could be very quiet compared to normal jets, rotors and propellers: it might also offer a fallback emergency landing option in the event of a main-engine failure.