A little over a year ago, we told you about NASA’s Green Flight Challenge that is offering US$1.6 million in production funds to the winning design for a for low-cost, quiet, short take-off personal aircraft, that require little if any fossil fuel. The competition, to be decided next July, is being run by NASA’s light-aircraft partner CAFE (Comparative Aircraft Flight Efficiency), which envisions the resulting Suburban Air Vehicles (SAVs) taking off and landing at small neighborhood “pocket airports.” At last week’s Future of Electric Vehicles conference, CAFE president Dr. Brien Seeley outlined just how those airports would work.

“The shocking news is, that after a full century of flight, aviation still fails to fulfill the fundamental purpose of moving people fast without need of roads,” he began. “We now believe that green technology can solve this.”

According to Seeley, by the time travelers have made their way by ground to their city’s one main airport, and then traveled again by ground from the destination airport to their final destination point, the speed with which the waiting airliner will get them there has been negated. The solution, he explained, is 2 to 4-passenger SAVs that could ferry people between the main airports and conveniently-located pocket airports.

The Green Flight Challenge, he explained, is just the first step in NASA’s plan to develop a new aviation infrastructure, in which quiet, auto-piloted aircraft would deliver people and goods on a point-to-point basis, within communities. In order to qualify for the prize, planes will have to get at least 200 mpg (1.18 L/100km), go at least 100 mph (161 kph), emit no more than 78 decibels from a 250-foot (76-meter) distance, and have a take-off distance, clearing a 50-foot obstacle, of less than 2,000 feet (or a 15-meter obstacle at 610 meters).

For its pocket airports concept, however, CAFE would like to see those requirements ultimately taken even further – Seeley said that his group envisions SAVs that get well over 200 mpg, cruise at over 120 mph (193 kph), emit less than 60 dBA from 125 feet (38 meters), and have the ability to take off in a distance of under 100 feet (30.5 meters). Safety would also be a major consideration.

“This is what the SAV would offer you: a fast vehicle with an open road and no traffic,” he said. “The pathway you get through the sky is de-conflicted, so there’s no one else on that road, and you go directly where you want to go.” The various planes’ flightpaths would be coordinated by a central control system, to keep them from flying into one another, and each SAV would be equipped with a parachute.

The basic single-runway pocket airports would be no larger than two acres (0.8 hectares) in size, and located in greenbelts just outside major urban areas. They would be capable of 120 operations per hour, as rows of SAVs/air taxis would wait for their turn to take off, one going every 30 seconds. CAFE also has designs for a 4-acre (1.6-hectare) airport that would have three runways arranged in a triangle, that would be capable of 260 operations per hour, plus an 8-acre (3.2-hectare) version with two end-to-end runways (with a large space in between them), and a 12-acre (4.8-hectare) version with two sets of the end-to-end runways and parking for 320 ground vehicles.

The airports would require SAVs to be capable of a very steep take-off, as the planes would have to be at least 150 feet (46 meters) in the air by the time they cleared the airport’s boundaries – “high enough to not be heard by the back yard barbecuers in the residences nearby.”

Development of such vehicles won’t happen overnight, needless to say. Once the first Green Flight Challenge is over, CAFE would like to see a second one take place in 2013, that would award US$2 million for the development of ultra-quiet, ultra-short-runway SAVs, followed by a third one in 2015, that would offer up US$2.35 million to whoever is able to make the winner of Challenge #2 autonomous.

“The gridlock we face now is going to get worse,” Seeley stated, citing research into congestion on the world’s roads. “This is a form of insanity... We need to travel in 3D.”

All images courtesy Dr. Brien Seeley