Original URL: http://www.theregister.co.uk/2007/10/10/transition_flying_car_quite_realistic/

Fairly realistic flying car offered for 2009 delivery

It's a car. It can fly. That's it.

By Lewis Page

Posted in Science, 10th October 2007 15:45 GMT

One of our favourite notions here at Vulture Central is that of the flying car. Ideally this would be a true sci-fi-style job, backed up by an equally puissant automated air-traffic infrastructure. In such a machine you could simply jump into your car outside your house, quietly lift off vertically, fly somewhere even in bad visibility and congested airspace, and set down again equally vertically. Then you could drive/taxi your astounding hover vehicle into the garage, underground carpark or wherever - or simply park it on the street.

Sadly, the nearest approach offered by current technology is the helicopter. Whirlybirds are noisy, dangerous, expensive and difficult to fly. They take up a hell of a lot of room, too, in the contexts both of airspace and manoeuvres near/on the ground. They aren't going to turn into flying cars any time soon.

'But honey, your mom doesn't have a runway'

- it won't wash any more. Credit: Benjamin Schweighart

Jump-jets like the Harrier are even worse, in that they can't at present get airborne vertically with a useful load. Ducted fans sometimes seem to offer hope, but the idea has been around for a long time without much in the way of credible kit appearing. The large thrust-disc diameter which a rotorcraft can offer - which is what makes helicopters and tiltrotors a going proposition - doesn't seem feasible for ducted fans, and in any case leads to an undesirably large ground footprint.

Even once you've dealt with all that, there are still the inevitable safety and certification issues that would come with a many-orders-of-magnitude increase in numbers of aircraft over densely-populated areas.

So we probably aren't getting a real flying car any time soon. Current technology could, however, offer something a bit more exciting than the ordinary light aircraft which have been flying almost unchanged since the 1950s. In fact, various inventors and engineers have been working on so-called "roadable" aeroplanes for a long time.

The idea here is that you still have your trusty flying vehicle parked in your driveway or garage, taking up no more room than a regular motor. You stroll out, fire it up and drive it away to a nearby airstrip. Here you extend/attach the wings, prop etc., and it's up, up and away. When you get to your destination strip, you land, convert back to roadgoing configuration, and trundle along to where you're going.

Under NASA's Personal Air Vehicle (PAV) concept, this relatively realistic idea gets some hard-to-achieve bells and whistles added on. A proper NASA PAV is also very quiet and can take off from very short runways, which could permit handy little airstrip-laybys to be scattered all over the place: at shopping-mall carparks, suburban housing estates, major road junctions etc. Better still, the PAV's amazing "synthetic vision" autopilot would be able to interface with a super-duper airtraffic network of the future so as to handle the plane nigh-on autonomously. This would mean that learning to fly a PAV would be no more demanding than getting a regular driver's licence. The PAV could laugh at bad weather and controlled airspace too.

These tough tech hurdles have meant that the NASA PAV doesn't exist, and probably won't in the foreseeable future. But that doesn't necessarily mean that more basic roadable aeroplanes can't be built.

One such notion is the Terrafugia Transition®, reported on today by the MIT Tech Review. Terrafugia Inc is a startup founded by a group of MIT engineers and flying enthusiasts in 2006. It completed an initial funding round in December.

The Transition isn't a PAV; it's a normal light aircraft which can fold its wings at the touch of a button and become a car, and which runs on unleaded. That's pretty much it. The only extra touch is that a Transition® is intended to qualify as an FAA "Light-Sport Aircraft", which means a somewhat less onerous regulatory regime. A "Sport pilot" licence is easier and cheaper to get than an ordinary private pilot's licence, requiring only 20 hours logged; and there are breaks on maintenance, medical checks etc. An existing pilot's licence is also fine.

The Transition® in bad-weather mode. Credit: Benjamin Schweighart.

The Terrafugia people reckon that the advent of the Light-Sport category, combined with recent advances in materials and aero engines, mean that an airworthy and road-legal plane can now be built affordably. They say the market for it is there, with 600,000 licenced pilots who could already fly the Transition® in the States.

"The Transition® is for pilots," says the company.

"It is not intended for use by short-distance commuters, by people running errands, or for any trip through city traffic or under 100 miles. Instead... if you travel between 100 and 500 miles at a stretch, particularly if your trip is either starting or ending in a more suburban or rural area, then the Transition® is for you. If you don't already have a pilot's license, you will need to get one... The Transition® is for pilots, businesspeople [and] weekend travelers..."

Most of the target market pilots don't have instrument qualifications allowing them to operate in bad weather. This means that they often fly somewhere, then get trapped on the ground by poor conditions. They also find the hassle of getting to and from airstrips a problem, according to Terrafugia; not to mention the faff attendant on aviation fuelling, tiedown places and so forth.

None of that applies to the Transition. You drive it to the airport from home, filling up at an ordinary petrol station. You fly wherever you're going. Once there, you aren't bothered about a place to tie down, or about a ride onward to the ultimate destination. You simply fold wings and drive away. If the weather closes in before your return flight, no hassle about hire cars or getting the plane back home again - just drive back home on the ground. It'll take a bit longer, but you'll get there. Likewise, if your flight runs into bad weather and you can't carry on, divert to an open airfield and drive from there.

All in all, this sounds a lot more realistic than a ducted-fan flying saucer from the endlessly written-up Dr Paul Moller (who was busted by the SEC in 2003 for flogging fraudulent "Skycar" stock on the internet and other financial misdeeds). It also sounds a lot more feasible than a silent, super-efficient short-takeoff NASA PAV with accompanying automatic air-traffic miracles.

Terrafugia reckons there are two main tech hurdles to jump before the Transition is ready to fly and drive. The first of these is the one-touch folding wings, which the company believes it has cracked. A demonstration wing has been built and tested successfully.

The remaining trick is not the engine - the Terrafugia mob reckon an existing Rotax job can do everything they need - but the transmission, which must be able to switch easily between driving the propeller and the wheels. It also has to be light, in order to keep the Transition within the FAA limit of 1320 pounds for a light-sport aircraft.

Anna Mracek Dietrich, Terrafugia engineer and COO, spoke to Tech Review.

"Going into this, we knew our two biggest design challenges to make it practical would be the wings and the power train," she said.

"By validating the durability of the wing's construction and engineering, we've checked one major design challenge off of the list, and now our focus is on the second."

One might also suspect that there will also be major challenges in getting the Transition certified as road-legal. This is traditionally a big stumbling block for flying-car inventors, who are often FAA-savvy but less well acquainted with the National Highway and Traffic Safety Administration (NHTSA).

"We've made inroads with both [regulators], especially the FAA," says Dietrich.

The company expects to begin flight testing next year, and deliveries from "late 2009". The business plan calls for production of between 50 and 200 Transitions annually, selling for $148,000 a pop. Terrafugia says that all its anticipated production through Q2 of 2010 has been reserved already (the refundable reservation deposit is $7,400, held in escrow) though it won't say exactly how many that is. However, the investor sheet (pdf) quotes customer number 29, so presumably at least that many orders have been placed.

For your $148k you get two seats, cruising speed of 115mph in the air (or normal motorway performance on the ground), 25 miles per gallon flying on super unleaded, and 460 miles flight range.

One of the weaker stats on the spec sheet (pdf) is the useful load - just 550lb. Up to 120lb of that will be taken up by fuel, so the Transition won't get airborne freshly topped up with two heavyish people. It certainly won't carry much baggage, unless flown solo or with very little fuel.

Budding secret agents or master criminals should also note that you can't just pop the wings out during a high-speed chase and take off: the button will only work with the vehicle stationary. There's no air-con, either.

Despite these limitations, the Transition looks very wantable indeed to your correspondent*. Regrettably, the Vulture Central scriven-remuneration package doesn't permit the purchase of £74-grand conveyances.

Perhaps they'll let us have one for review ahead of the UK launch. The MIT Tech Review piece is here

*A somewhat rusty, strictly VFR private pilot.