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.
Operates without much human piloting = can do without humans altogether = safer than normal cars?
At a wild guess, "morphing vehicle body" might mean extendable wings or some other means of generating lift from forward motion in flight, allowing the TX to cruise from place to place economically using less thrust while charging up batteries or ultracapacitors drained by a vertical liftoff. "Ring motors" would see the ducted fans driven by machinery located around the outside of the blades, built into the duct walls rather than at their hubs.
DARPA seem to hint that the "advanced flight controls and flight management systems" would be so sophisticated as to allow the TX to fly unmanned if required. They say that "[One-person] TX vehicles could be dispatched for downed airman recovery or for evacuating injured personnel from difficult to access locations".
This makes sense: an autopilot system so good that an ordinary soldier could fly the TX would be effectively capable of unmanned operations anyway. Heavily automated controls and flight-management would also help to counteract the inevitable human errors among drivers/pilots which make the roads so dangerous today and which could make skies full of flying cars undesirable tomorrow.
DARPA also make it clear that the TX would be very suitable for operations in built-up areas:
The TX vehicle is intended to make roads irrelevant for military small unit manoeuvres. These units can use TX air vehicles to fly over obstacles or impassible terrain, avoid ambushes and improvised explosive devices ... or to resupply isolated small units. Four-man versions would be suitable for enhanced company operations concepts which would allow the soldier/team to see the situation and pick the best place to “drop in” for urban operations.
That seems to be pretty much a clean sweep on the proper-flying-car checklist: it's quiet, it hovers, it's so automated that ordinary humans can use it without undue danger to themselves or others. That's a proper Jetsons flying car, if it can be built.
As DARPA say, such machines could indeed have revolutionary effects on small-unit tactics. One- to four-person air buggies able to hop over buildings and fly around towns below rooftop height (or ten thousand feet up) would no doubt get shot down or blown up on occasion, but they'd usually be harder to nail than ordinary one- to four-person military units.
But, like the internet (perhaps DARPA's most famous invention) you can see the civilian applications reaching further and faster here than the military ones. Assuming the technology ever gets off the ground, anyway (ahem). All that's scheduled for next year is "trade studies, preliminary design studies ... and modelling". ®