The Personal Air and Land Vehicle
This is a classic Damn Interesting article which was originally published on 20 December 2005.
Despite many technological innovations, the twenty-first century has so far completely failed us in two key departments: Flying cars, and transformers. Fortunately, we have the Dutch, who do not allow such oversights to continue unchecked.
A Dutch entrepreneur named John Bakker is working closely with Spark design engineering to develop the Personal Air and Land Vehicle (PALV), a single-occupancy transportation unit which drives like an enclosed motorcycle on the ground, yet when necessary, it can unfurl its rotors and transform into an honest-to-goodness autogyro. This allows it to leap into the air on short notice, and cruise around at altitudes below the level of commercial air traffic.
In its earthbound mode, the narrow three-wheeled vehicle is highly aerodynamic, and as agile as a motorcycle thanks to the tilting mechanism which allows it to lean into curves. It is expected to have a top speed of over 125 miles per hour, and due to its light weight, it should have a zero-to-sixty time of under five seconds. It is also projected to have excellent fuel economy, reaching about 70 miles per gallon.
When airborne, the PALV flies under the 4,000 feet– which is the floor of commercial air space– so no flight plan is required in order to launch. It has Very Short Take Off and Vertical Landing (VSTOVL) capability, so it needs a short runway to take off and to land, but it requires significantly less runway distance than a traditional airplane. Some autogyros require so little launch distance that they can operate from helipads, but the PALV requires at least 165 feet on takeoff, and 16 feet in order to land. Its airspeed can range from as slow as 18 miles per hour to as much as 120 miles per hour.
Autogyro technology looks a lot like helicopter technology, but aside from appearances, they are quite different. Technically speaking, an autogyro has much more in common with an old-fashioned single-prop airplane than it does with a helicopter. An autogyro’s rotor is unpowered, providing lift in a way similar to a fixed wing, but caused to spin by its forward motion through the air. The thrust that provides lift comes from an airplane-like propeller– in the case of the PALV, a small pushing-type propeller mounted to the rear of the vehicle.
An autogyro like the PALV is not as fast or efficient as a helicopter or an airplane, and unlike a helicopter, it cannot hover. It is also susceptible to unique emergencies, such as Pilot-Induced Oscillation, where the craft bucks uncontrollably due to improper pitch adjustment; and Power Push-Over, where the aircraft somersaults out of control due to improper handling and throttle settings. But the PALV designers may be planning preventive measures to avoid these situations, perhaps by using onboard computer monitoring.
Despite the problems inherent in an autogyro design, the PALV also has its advantages over other types of aircraft; for instance, it is much quieter than a helicopter (70 decibels compared to a typical helicopter’s 105 decibels), and because the “wings” are spinning, the aircraft cannot stall. Additionally, in the event of engine failure, an autogyro will not nose dive, but descend vertically with mechanical steering still available, so a safe landing can usually be made.
In anticipation of the flying car revolution which has been on the horizon since personal air vehicles were first imagined, NASA has developed a system for handling large numbers of low-altitude aircars, called “The Highway in the Sky” (HITS). It uses GPS to define low-altitude virtual highways which low-flying aircraft can follow to avoid mid-air collisions. Of course the system can also be used for conventional aircraft at higher altitudes.
The PALV is intended to run on high-octane (95-98) unleaded gasoline, and though no price has been publicly announced, its cost has been compared to that of a luxury sedan. It’s not the only flying car concept being developed, but it looks to be one of the best land/air hybrid designs yet. And by the sound of it, it may be one of the most affordable.
Further Reading:
PALV Press Release
NASA article on the Highway in the Sky (HITS) system
|
Forthcoming
|
Forthcoming
|
|
On the contrary, Alan, there is a transformer at every street corner, making incessant buzzing noises.