Scotland's first electric-powered aircraft begins Orkney test flights

Scotland's first electric-powered aircraft has taken to the skies from a new test centre in Orkney.

One of the twin engines in Ampaire's six-seater Cessna Skymaster has been replaced with an electric motor.

The company believes it could pave the way to retrofitting inter-island and short-haul flights with greener technologies.

It is the first low-carbon aircraft to fly at the £3.7m sustainable aviation facility based at Kirkwall airport.

The plane was built in 1974 but has been retrofitted at the company's headquarters in California.

After initial test flights in Hawaii, it was shipped to Scotland for its first flight across open water between Orkney and Wick, a 37-mile (60km) flight.

Test pilot Justin Gillen told BBC Scotland: "It's the only hybrid-electric airplane that I know of flying today.

"As the airplane is approaching, you hear the propeller which is a kind of blade-through-air sound and then you hear the throatier sound of the engine. With our electric engine, you hear the propeller but that's pretty much it."

On Ampaire's aircraft, the engines are built at the front and back of the cockpit in a "push-pull" design.

It's the front engine which has been replaced with an electric motor that's a fraction of the size.

A huge battery pack has been attached to the underbelly which can keep the aircraft running for several hours in the right conditions.

About 90 minutes of rapid charging would provide around an hour of flight.

Susan Ying from Ampaire said: "It will fly cleaner, be more efficient and more economical.

"It will start as a short-haul but eventually, as the technology's improving, it could go into medium to long-haul."

That would require batteries to continue shrinking but the developers are confident that will happen.

Air travel is a notoriously difficult industry to decarbonise because the aviation fuel has a high energy density.

But it's a high emitter of carbon dioxide which needs to be reduced to net-zero if we are to halt climate change.

Island air links in Scotland are regarded as "lifeline" for communities who live there, and so battery-powered flights are under serious consideration.

Dougie Cook, from Highlands and Islands Airports, explained: "If aviation is to survive throughout the world, then it needs to decarbonise and it needs to do so quite quickly. So this is a really important first step.

"The links around Orkney are called lifeline links for a reason and it's absolutely essential that we keep them going so electric aviation will guarantee that and make it sustainable for the future."

Flights currently operate from Kirkwall to six of the furthest islands - Eday, Sanday, Stronsay, North Ronaldsay, Westray and Papa Westray.

The test facility is expecting to play host to other forms of low-carbon flights, including hydrogen and sustainable aviation fuels.