AIRVENTURE: Sonex plans battery-powered engine

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Source: Flightglobal.com
This story is sourced from Flightglobal.com

Oshkosh-based Sonex Aircraft promised to push the cutting edge of electric-powered aircraft by revealing plans to build its own highly efficient motor.

Across the runway from the week-long AirVenture in Oshkosh is the permanent home of Sonex, where the light sport aircraft manufacturer has been working with AeroConversions Products to develop a brushless DC cobalt motor and efficient energy and charging system.

The goal is to use existing lithium ion and lithium polymer batteries to power this new engine for a 25-45min flight at speeds up to 115kt (210km/h).

"Our initiative will broaden and refine our vision of what efficient, low-cost sport aviation will be for generations to come," says Sonex founder and president John Monnett. "It should serve as a beacon to attract serious sponsors for this important effort."

In 1994, three years before Sonex was founded, Monnett and Pete Buck embarked on their goal of short duration electric-powered flight. Buck, who works full-time as an engineer at Lockheed Advanced Development, is Sonex's chief engineer.

He also spent nine months analysing and building a battery power system for Ford hybrid vehicles. He concluded that batteries of the time could work, but would have a flight duration of only 10min. That was before the recent boom in handheld electronic devices, which employ improved batteries that would power the engine designed in-house.

Sonex says it is the most powerful, efficient and lightest engine of this type produced. The three-phase, 270v, 200 amp motor will have up to 90% efficiency. CNC machined anodized aluminium and nickel-plated steel parts are all part of the prototype, which weighs 23kg (50lb). The proof-of-concept was revealed on 24 July.

"It has not flown yet," says Sonex. "We are developing the motor, the controller, the battery system. We've got to get this done before someone else does it. Everything is in-house and proprietary."