Electric Airplanes

California County Takes Lead in Electric Training Aircraft

Jul 7, 2017 Graham Warwick | Aviation Week & Space Technology

Introducing electric-powered aircraft into flight training promises substantial cost reductions but poses significant challenges. Electric aircraft have dramatically lower operating costs, but flight time on today’s batteries is limited, charging infrastructure is nonexistent, and public and pilot acceptance is unproven.

As has happened with electric cars, pioneers are taking on the challenges of not only developing the vehicles, but also deploying the infrastructure to support them and understanding how electric powertrains can change how they are operated and maintained.

Fresno County in California’s Central Valley is taking a lead in bringing electric aircraft for flight-training to the U.S. by providing more than $1 million in funding for the Sustainable Aircraft Project. This is paying for four Pipistrel Alpha Electro electric trainers and charging stations at four airports.

The goal of the project is to prove electric aircraft are viable by not only deploying the trainers, but also developing the network of airports to support them, creating a model that can be replicated elsewhere in environment-conscious California and across the U.S.

A way to certify the electric-powered Pipistrel Alpha Electro for flight-training in the U.S. is still being sought.

“We want to use electric aircraft to reduce the cost of training pilots,” says Joseph Oldham, director of Calstart’s San Joaquin Valley Clean Transportation Center, which manages the project. Operating costs for the Electro are estimated at $1.40-2.00/hr. versus $40-50 for older aviation gasoline-fueled trainers, he says.

The project aims to overcome the limitations of early electric aircraft. The Electro, with only a 1-hr. flight time, is designed to fly airport traffic patterns. “But schools are not willing to spend $140,000 on a pattern trainer when they can buy a 35-40-year-old Piper Warrior or Beech Sundowner that students can beat up in the traffic pattern,” Oldham says. However, most older trainers lack the Electro’s modern cockpit.

By equipping a network of airports within the Electro’s 85-nm range with charging stations, the aircraft can be used for primary training. Student pilots can make a cross-country flight, stop to recharge the batteries—which takes 45 min. after a 1-hr. flight, he says—then return to base.

To prove the concept, Fresno County has provided grants to the cities of Mendota and Reedley to each buy two Electros and two charging stations from Slovenia-based Pipistrel. Deliveries are expected in October, Oldham told the American Institute of Aeronautics and Astronautics’ Aviation conference in Denver in June.

A 10-kW, single-phase charger will be installed at William Robert Johnston Municipal Airport in Mendota, where it will service two new hangars being built as part of the project, while 20-kW, three-phase chargers will be installed at Reedley Municipal, Fresno Yosemite International and Fresno Chandler Executive airports.

In addition to the aircraft, chargers and hangars, the Sustainable Aircraft Project funding includes $90,000 in training assistance grant funds for youth from disadvantaged communities in Fresno County.

The project is expected to demonstrate significant operating cost savings over conventional training aircraft, through lower prices for electricity versus avgas and reduced maintenance, as electric drives are much simpler than piston engines, with few moving parts to wear out.

The project will also address the changes in pilot training that come with all-electric aircraft. Many of the issues pilots still learn to handle on piston-powered trainers no longer apply with electric propulsion, Oldham says, such as magneto checks, carburetor icing, spark-plug fouling and loss of engine power with altitude.

Operations have to adapt as batteries have a fixed weight—aircraft weight does not change as energy is consumed. Fuel is no longer traded for passengers, but there may be a limit on student weight until battery performance improves. Electric aircraft can also regenerate energy during the descent.

Oldham says the project has already attracted interest from Minnesota, North and South Carolina, and talks are underway with a flight school in Palo Alto, California, about locating a charger at an airport midway between the Central Valley and the Bay Area, and well within the Electro’s flying range.

Portable solar-powered charging stations, such as the EV ARC produced for electric vehicles by Envision Solar, are being looked at for a future expansion of the network across Central Valley. These could support electric cars and trucks as well as aircraft, says Oldham.

The project hopes to begin operations early in 2018, but one hurdle still to be overcome is certification of the Electro in the U.S., where light sport aircraft rules do not permit electric propulsion. Talks are underway with the FAA. “We are working on figuring out a path to get the aircraft into service,” he says.

Oldham sees the Fresno County project playing a key role in helping both regulators and the public become more comfortable with electric-powered aircraft. “Someone has to start,” he says. “We will put them into operation and show they are functional.”