Boeing technical experts check the feasibility of Personal Air Vehicles

BY GARY SANDERS

One of the world's busiest highways, the San Diego Freeway in the Los Angeles area, runs past the home of Darold Cummings, a recently retired Boeing employee and former Technical Fellow who used to spend an hour or more in traffic on his way to work.

So when he was asked to head the second Technical Fellowship Advisory Board (TFAB) to investigate the feasibility of Personal Air Vehicles and the system that would support them, he had a more-than-personal stake in it.

"When we started working on the demonstration models, my kids wanted to know when we would have it done," Cummings said. "They couldn't think of anything more cool than arriving at school in what amounts to a flying car."

AIR VEHICLES FOR THE INDIVIDUAL

So what exactly is a PAV? If you've ever watched "The Jetsons" or a "Star Wars" movie, you'll quickly get the idea. The personal air vehicle is a modification of a small, personal helicopter that you can also drive on the roads like a car. While in the air, the vehicle would fly itself, much like Boeing's X-45 Unmanned Combat Air System: Its route or "mission" would be entered in before the journey. Air traffic management systems would keep the vehicles at a safe distance from one another and allow them to blend in with other piloted aircraft. On the ground, the PAV would be driven as a standard road vehicle. The team also looked into various methods of powering the PAV, deciding that a hybrid diesel/electric engine would provide the best balance of power and economy.

Based on existing technology, actual flying subscale models have been built, and a full-scale PAV could be built today.

Boeing Phantom Works President Bob Krieger asked the Technical Fellowship to set up a TFAB to look into the possibilities of personal air vehicles as a potential "white space" project for many years down the road. Cummings was tapped because of his reputation for creativity and technical leadership, his network of personal relationships with key industry experts, and his expertise as a hands-on mechanic. Although retired as a fulltime employee, Cummings continues to lend his technical expertise to Boeing projects and programs.

PUTTING TOGETHER THE TEAM

Cummings began by pulling together a team of Boeing Tech Fellows and other Boeing technologists, as well as people from NASA and the Georgia Institute of Technology. With the team in place, they began to establish the goals of the project.

"Obviously, the big objective was to increase mobility," Cummings said. Since people want to spend less time getting to their destination, Cummings said the team realized it needed to reduce certain factors, including total travel costs, average travel time, and travel-time irregularities such as unexpected traffic jams.

"The optimal solution had to be a balance of these factors-increasing any of these while decreasing others defeated the purpose," he said. "What we decided to work on was improving the functionality of an automobile by giving it 3D mobility-you know, so it could fly."

Taking current flying options, they looked for what the group dubbed "roadability," or the ability to be driven on a road. Personal space packs that the military has been investigating, for instance, permit flight but can't be driven after landing. Also, because of limitations of current engines and lift capabilities, hovercraft are currently too cumbersome, unreliable and noisy. However, the team realized that a hybrid mix of the car and a small airplane or helicopter might be feasible.

Another consideration would be where a PAV could land. "We realized the need to be able to land in a fairly small area," Cummings said. "The obvious landing spots to me would be the cloverleaf interchanges of major freeways. They have huge open areas that are generally not used for anything except growing weeds, and they are usually near places people want to go."

RIGHT HERE, RIGHT NOW

A working radio-controlled model of the PAV has been built and is being flight-tested in Seattle. The vehicle, which looks remarkably simple, is a personal helicopter with opposite-spinning rotors that can land in fairly tight quarters ("right on the street in front of my house, if necessary," Cummings said) and with rotors that can be easily folded away during regular driving.

Built after extensive study of the existing vehicles, which included determining the ability of flying craft to avoid tipping during road driving and balancing the differences between cars and motorcycles (with a three-wheeled vehicle winning out), the team came up with a feasible model that could eventually be put into production at a fairly reasonable cost.

However, the cost and capability of producing the vehicle were only two of the challenges.

"The Federal Aviation Authority and local Department of Motor Vehicles will no doubt have a strong debate about who has controlling authority," Cummings said. "Now there's something I would rather not get in the middle of, because I think designing and building the vehicle is going to prove a lot easier than the jurisdiction battle."

Krieger, who initiated the program, has seen the progress the team has made and is very enthusiastic about the PAV. "The TFAB2 team exceeded my expectations in both analyzing proposed PAV concepts and recommending a fascinating option that overcomes their shortfalls," Krieger said. "This is a great example of the creativity of our Technical Fellows and their network of technical contacts."

The team's recommendations are now being reviewed by Boeing's strategic planning team for possible use in future integrated transportation systems.