26 April 2016
Due to fly this summer is an electric version of Extra’s two-seat aerobatic aircraft 330, which had its debut at AERO. The engine bay is full of batteries as well as Siemens 260kW (350hp) SP260D electric motor and has been produced to flight test Siemens developing electric motor technology.
“We have this 260kW/350hp motor SP260D and we need a flying testbed for it,” said DR Frank Anton, head of Siemens electric aircraft programme. “To try this drivetrain you need a very strong aircraft and obviously the Extra is very strong because it is an aerobatic plane. We will be changing components and for this it’s best to work with a company that is as flexible as Extra.”
As well as testing its electric drivetrain, Siemens will also be testing different types of battery.
“This one is optimised for high power and relatively short flights,” said Dr Anton, who is also a private pilot and flies aerobatics. “A typical aerobatic programme is just 5 minutes so if you have 20 minutes of flight time, you have plenty.”
That’s a lot of batteries packed in the Extra’s engine bay, behind the Siemens electric motor.
The two-seat Extra 330 is certainly strong with a carbon fibre wing assembly and tail, and a fuselage frame made from 1.7734 steel tube. The aircraft is certified for +/- 10g. It’s normally powered by a 315hp 6-cylinder Lycoming AEIO-580 with a 3-blade MTV propeller, that takes up about a third of the aircraft’s total empty weight of 660kg. The Siemens SP260D motor weighs about 50kg so that leaves plenty of weight available for batteries, especially since no fuel needs to be carried.
