Two experimental electric powered aircraft are on display this week: the "Electraflyer-C" (AeroShell Square) and the Sonex electric airplane (EAA Welcome Center), and interest in the airplanes has been extremely high, according to their builders.

A group of industry experts met with EAA and FAA officials late Friday to begin identifying what design standards would be needed for an electric light-sport aircraft (LSA), and to gauge the enthusiasm of the industry and pilots for bringing an electric LSA to market.

The current FAA regulations allow only reciprocating engines in the LSA category. That rule was written to prevent the use of turbine or jet engines in LSAs. EAA has asked the FAA to permit the use of electric engines in light-sport aircraft and ultralights, through two exemptions to the rule. One would change the definition of LSA to include electric propulsion. The other would change the way an ultralight’s maximum empty weight is calculated. Currently an ultralight’s empty weight does not include the allowed five gallons of fuel, but would include the weight of batteries to power an electric motor.

EAA’s proposal would change the way empty weight is calculated for an electric powered ultralight.

An FAA official at the LSA electric propulsion meeting on Friday said the FAA is receptive to the idea of electric propulsion for LSAs, but the agency wants to see a design standard written for electric LSAs before it will issue the exemption. LSA uses ASTM consensus standards.

"We should figure out what is the minimum that can be done [to write a new standard] that would allow an electric flyer to fly as an LSA," said Earl Lawrence, EAA vice president for government and industry relations.

Jeremy Monnett of Sonex Aircraft agreed: "Different manufacturers and systems will approach [the problems of electric flight] in different ways, but you don’t want to write the standard to a given system." The technology is advancing rapidly, he added, and the standard should give each manufacturer the flexibility to innovate.

Lawrence noted that writing new standards for electric flight will require a lot of effort, and asked the group, "Are we sure this standard would get used?"

"There is an electric aircraft out on the field that could be brought to market tomorrow," Monnett said. "The standard will get used."

"A lot of pilots have tried to give us money for a deposit on an electric Sonex," he said.

"People want to buy an electric airplane." Sonex is not accepting deposits or orders for its electric flyer, he added, but as soon as the FAA clears the way for an electric LSA, manufacturers will build it.

"To begin," said Lawrence "we need to determine what standards are already out there for electric motors, motor controls, batteries, and other components; and we need to review the existing LSA standards, to identify what items need to be addressed."

Members of the group agreed to begin reviewing the LSA standards and developing a list of items requiring new standards. They agreed to reconvene in October to finalize that list. Among the many items a new standard will have to address are:

• Electric motors and motor controls

• Batteries

• Measurement of useful load—since there is no fuel burn off with batteries

• "Fuel" gauges—measuring the remaining useful charge in the batteries

• Chargers, charging voltage, charging plugs, and receptacles.

• Other questions to address include:

• How will a motor and batteries affect the crashworthiness of an LSA?

• What will first responders and rescuers need to know about electric propulsion systems?

• How will an electric propulsion system respond to a water ditching?

• How will airports accommodate airplanes wanting to plug in and recharge?

The group agreed on a goal of preparing a draft standard by AirVenture 2009. Members expressed the hope that an electric LSA could be brought to market in two years. Both the FAA and designers want new design standards in place before an electric LSA goes on sale.