The Incredible Electric Airplane
By Bill Moore
EV World asked Dunn what his performance goals for his electric aircraft is. He responded that he wanted to come as close as possible to matching those of the reciprocating engine version, which is a pretty daunting challenge. The American Ghiles Lafayette is one of the most efficient light aircraft every built. Due to its composite construction, it is capable of carrying two adults at speeds in excess of 160 mph using only an 80 hp engine. In contract, the venerable Cessna 150, on which millions of private pilots trained, uses a 100 hp motor and can do no better than 120 maximum cruise.
The version of the Lafayette that Dunn is proposing to use has a special STOL or short take-off and landing wing that is 28 feet long and incorporates special control surfaces. He says he's going to need all that wing area and STOL technology because unlike a normal aircraft which lands lighter than when it took off, the E-Plane will be heavier when it lands.
He explained the reason for this anomaly. Because the fuel cell is taking oxygen from the air to create electricity in the fuel cell, it also creates water. This means the airplane is continually adding a slight amount of weight as it flies.
Another potential problem with using a fuel cell and generating water vapor is icing. Dunn didn't seem overly concerned about this, explaining that whatever excess water vapor the fuel cell generates, some of which he will keep onboard to act as a fuel stack humidifier, he can vent the remainder overboard, probably from the tail of the aircraft.
There is little concern with the fuel cell stack itself freezing because of the amount of internal heat that it generates.
Powering an aircraft with 300 volts and 600 amps of electric power could present Dunn with yet another challenge by disrupting the plane's avionics, its radios, navigation aides and flight control instruments. While he admitted that this could be a concern, he felt that with adequate shielding, he shouldn't have any problems here. He also pointed out that there will be few electronics on the first prototype aircraft.
"This is more a demonstration project, but ultimately it could be an issue," he agreed.
Dunn had originally planed to fly the battery version of the airplane at a popular aviation gathering held annually in Florida in early April 2002. However, the tragic events of September 11th have changed that. Due to concerns about terrorists using small airplanes, the federal government has place severe restrictions on general aviation. As a result, Dunn says he's been "locked out" of his hanger.
"I've not been able to do anything on the airplane. Unfortunately the World Trade Center has changed the lives of pilots in the aviation more than anything." He commented that the very first airport in the country at College Park, Maryland is still locked down. As a private pilot who commutes frequently between his home in Massachusetts and the nation's capital, this has complicated his life, as well.
Dunn said he has meet recently with a gentlemen that has his own private airport and hanger that is not under the control of MassPort, and there is a chance he can relocate his project to this man's facility.
We asked Dunn what kind of reception he received when he attended the annual EAA Fly-In in Oshkosh, Wisconsin this past summer. He explained that he has two version of the Lafayette, the one that will be converted to electric and a second that still has its Rotax gasoline engine. He flew this version to the Fly-In.
He said that the "reaction was phenomenal."
"We had a few skeptics, of course. A few people were a little dubious that we would ever be able to duplicate the same range of the gasoline version." He admitted that "at this stage [it] is difficult to see where the convergence may come," though he pointed out that the Wright Brothers first attempts didn't fly very far either.
Looking somewhat into the future, Dunn sees a fairly rapid evolution of the fuel cell due directly to the billions of dollars being spent on research. He thinks that eventually when a truly practical fuel cell aircraft engine emerges, it will not be a PEM cell, but probably either a solid oxide or possibly a direct methanol fuel cell. The latter would greatly simplify the fuel issue since liquid methanol is a readily available fuel and well understood, compared to hydrogen or other fuel types.
A project like this seems like a natural for NASA, which also engages in basic aviation research, besides running the nation's space program. Dunn told EV World that he does have two proposals into the agency under the Revolutionary Propulsion Concept Initiative and hopes to hear by December if either will be chosen for funding. One of the proposals would continue the direction of his current research, while a second would look at the role of automotive fuel cells and an advanced, blended wing-body concept in partnership with Embry Riddle, considered by many the nation's leading aviation university.
Dunn has gotten the support of a number of sponsors including SAFT, the French battery manufacturer; Solectria, who is providing its electric drive conversion expertise. UQM in Golden, Colorado will probably provide the actual motor, he said, because they make some of the most efficient electric motors in the world. As for who will be providing the fuel cell stack, he didn't think he was yet liberty to announce who they are. He added, however, that they have made dramatic reductions in the weight of the stack and that NASA has funded their efforts. He's also had assistance from Millennium Cells and some other entities on the hydrogen sourcing side of the project.
As might be expected, a project like this can generate a lot of enthusiasm and excitement among the aviation fraternity and Dunn has received many offers from volunteers wanting to participate. Three of those volunteers are world-class test pilots.
Funding a project like this is just as daunting as actually achieving the goal of electric flight. Dunn created the FASTec foundation for this purpose. He estimates that if he has to pay for the batteries and the fuel cell, the project will run about $600,000. He is especially grateful for the generous assistance of both American Ghiles and Diamond Aircraft companies for providing him with aircraft. He explained that in the case of Diamond, he hasn't yet taken deliver of it because he "has his hands full right now."
He certainly does!
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