You head out the door and down to the street to catch your ride to work. The aircraft is waiting. The only sound is the low hum of ducted fans at the rear.
Where you’d once expected a pilot, there is instead a panel of blinking lights. To the left and right, more vehicles drop out of the morning sky to pick up your neighbors. You wave a card that opens the door, enters your destination into the flight planner, and debits your account, then spend the quiet, 20-minute commute reading, dozing, or sharing a laugh with your seatmate. The scene sounds like a fantasy because, despite great interest and the effects of “The Jetsons” cartoon on a generation of youth, the promise of affordable, automated flying commuter craft remains unfulfilled.
True, there are a plethora of small flying craft around—light sport and ultralights—but there is still no aircraft that, compared to a car, is as easy to operate. Designs for flying cars have been with us for decades, but no drive-fly vehicle designs have ever been submitted to the Federal Aviation Administration for certification.
In recent years, however, U.S. government agencies and private enterprises around the world have been developing the seed technologies that may finally give rise to this new form of aviation. The scenario of replacing cars, buses, and trucks with flying vehicles will be preceded by the introduction of propulsion systems and other technologies involving automated flight.
In the United States, the gurus of flying cars are researchers at NASA’s Langley Research Center in Virginia who have recently completed a four-year study of the possibilities of personal air vehicles. While NASA’s research funding of such craft is ending, veterans of the program say that much of the technology that is needed to launch the industry is either available in the private sector or achievable in the near term.
According to Dennis Bushnell, a NASA chief scientist and member of the Langley team, the first step toward a flying car is to take some of the burden of flying that traditionally fell on pilots and pass it on to computers. Bushnell says the ability to create an autonomous robotic vehicle will be possible “very soon.” He observes that the growing use of unmanned aerial vehicles by the U.S. government—including all branches of the military, the Department of Homeland Security, and the National Oceanic and Atmospheric Administration—is providing the technological breakthroughs necessary for personal air vehicles. “The initial personal air vehicle probably won’t be inhabited,” Bushnell says. “It will be a civilian version of a military UAV to do robotic package delivery.”
What would follow fast on the tail of an unmanned pizza delivery pod would be a commuter version: “Think of unmanned aerial vehicles with humans as cargo,” Bushnell says. He envisions an air vehicle that can also drive on the ground, yet still costs less than $50,000. “It will not fly high and not very fast—say, 120 knots [138 mph]—and feature a two-passenger climate-controlled cockpit,” Bushnell predicts.
The engineer says that at least initially the vehicles will employ super-short takeoff and landing. “You need something that will take off on the 50 to 70 feet of street in front of your house,” says Bushnell. The vehicles will have to be affordable and safe. That may rule out rotorcraft, including tilt-rotor designs, Bushnell acknowledges: “They cost much more to own and operate and are inherently less safe.”
Even in sparsely populated areas, the vehicles will also have to be quiet. Many personal air vehicle proponents see ducted fans as the solution, since they are quieter and lighter than either propellers or rotors. The progress is quantifiable: In late May the FAA issued an experimental airworthiness certificate for the first vertical-takeoff, hover-capable aircraft with ducted fans.
The 65-inch GoldenEye 50 is a winged design that uses a propeller enclosed within a cylindrical body to hover. It was designed by Aurora Flight Sciences Corporation of Manassas, Virginia, under a Department of Defense contract as a platform to carry battlefield sensors. It’s just a matter of time, the company is gambling, before there will be a need for larger aircraft using the same technology. The GoldenEye 50 was designed as a technology development platform for the GoldenEye 80, a 150-pound ducted-fan aircraft.
Several private ventures are developing ducted-fan vehicles capable of vertical flight, but few are as far along as Israel’s Urban Aeronautics. The company’s X-Hawk, inspired by the Piasecki Flying Jeep of the 1950s and ’60s, uses a U.S.-patented control system. The airflow created by the ducted-fan engine is directed by two arrays of thin-blade vanes; one array at the inlet, the other at the outlet of the duct.
While the first X-Hawks will be military and rescue versions, Urban Aero’s marketing director, Janina Frankel-Yoeli, says that future models “will fulfill the role of a communal aerial vehicle, such as a schoolbus or commuter shuttle.” Company officials say the first full-scale prototype may make its first test flights in two and a half years.
Clearing the engineering hurdles is just the first step in creating a flying car. That car needs a person on board who acts more like a passenger than a pilot. That means pairing everyday folks with trustworthy onboard computers.
The NASA team at Langley developed two systems intended to develop sentient vehicles that could offer, according to a NASA report, “fully autonomous flight” for a lone pilot in nearly all weather “with confidence and relative ease.”
In the report, the pilot-craft relationship is compared to more familiar partnerships: “The pilot guides the personal air vehicle with the control stick and the [onboard programming, reacting to the pilot’s actions] negotiates turbulent air as best it can, just as a rider guides through the reins and the horse negotiates rough terrain.” If the pilot is distracted or makes a mistake, the computer vibrates the stick to alert him. If there is still no response, the system will divert the craft to the nearest airfield.
Andrew Hahn, an aerospace engineer at Langley who researched personal air vehicles, is hopeful but guarded about automated systems. “The automation will undoubtedly get better,” he says. “When the automation gets really good, we may allow the automation to fly without people, over lightly populated areas, but I don’t see high-energy UAVs flying fully autonomously in heavy traffic and over cities for a long, long time.”
A smart vehicle’s intelligence is determined by more than onboard technology. Someone or something has to keep vehicles from colliding. In airspace with many small personal air vehicles zipping around, a workable system may well require a totally automatic, redundant navigation and air traffic control system. Bushnell points to progress with some of the flight software the military has designed for unmanned aerial operations. Building on these advances, he says, a robust, automated civilian system could be established within a decade.
Others are not so quick to abandon the human element. “Fully automated air traffic management is still many years off—perhaps more than 50,” says NASA’s Mark Ballin, a Langley researcher of aviation operations and a member of an interagency team tasked with designing the country’s Next Generation Air Transportation System, commonly called NextGen.
The team is seeking to upgrade the air traffic control system to handle the two- to three-fold increase in flights and passengers expected by 2025. But NextGen will still need human controllers, and some within the team say that will never change.
The most important question of human involvement revolves around consumer preference and manufacturer courage. “From the manufacturers’ standpoint, aircraft are low-volume and high-liability, which quite frankly scares them to death,” notes Hahn. “From the average person’s viewpoint, they are unobtainable, dangerous, hard-to-use toys that are really annoying. As long as both parties believe this, the answer [to when personal air vehicles will fly] will be ‘never.’ ”
FAA spokesman Les Dorr says that technology development “will be driven by market forces and the ability to comply with FAA safety regulations. You might ask yourself ‘Am I ready to buy a ticket on a pilotless aircraft?’ ”
When the Langley team disbanded in 2005, NASA’s direct personal air vehicle research ended, but the dream continues. The space agency, working through the Comparative Aircraft Flight Efficiency Foundation, in August awarded $250,000 in prize money for its PAV Challenge for the design of a two- or three-seat vehicle with an 800-mile range and ability to use a short runway.
The victor was Vance Turner, owner of a short-wing Pipistrel Virus, a lightweight sport aircraft built in Slovenia. The craft can go 170 mph and gets 50 miles to the gallon.
The challenge is the first of five annual competitions being held through 2011. When and if consumers ever trust flying cars enough to want to buy one, the dreamers want to be ready.