The four-seat electric Taurus G4 had its maiden flight at Wittman Regional Airport (OSH) in Oshkosh Aug. 12.
The aircraft was developed specifically to compete at the next NASA challenge, called CAFE Green Flight Challenge 2011. This year, the competition prize pool amounts to $1.65 million.
The aircraft was first presented to the public at Oshkosh in July this year. According to an informal vote by the visitors, it was the ninth most attractive aircraft on display among 15,000 exhibited airplanes. Each year, the EAA awards a virtual “Dead Grass Award” prize (for the most viewed exhibit) to the 10 aircraft with most votes.
But everything was not so easy, according to company officials. “The electric propulsion represents an unknown factor so it presented some trouble for Pipistrel,” officials said in a prepared release. “It was a great challenge even to import the aircraft into the United States because it is powered by 450 pounds of lithium-polymer batteries, which can in certain circumstances be highly flammable. It was also extremely difficult to find an insurance company in the U.S. which was prepared to insure such aircraft.”
The company also had to find an American test pilot. The FAA requires that the first test flights must be performed by an American test pilot, while CAFÉ competition rules also demand an American pilot fly the aircraft at the race.
Fortunately, the Taurus G4 team managed to find an insurance company and convince it to accept the insurance challenge, as well as convince American test pilot Dave Morss to conduct the test flight program.
Pipistrel’s new, twin-fuselage plane was created by combining two Taurus G2 fuselages, connected by a 5-meter-long spar. A 145-kilowatt brushless electric motor, developed for Pipistrel’s new four-seat Panthera, is mounted between the passenger pods and drives a 2-meter-diameter, two-blade propeller in tractor configuration.
“The Taurus G4 NASA Racer is a technology demonstrator,” said Tine Tomažic, Pipistrel development engineer and the leader of the G4 development team. “It is the first-ever electric four-place aircraft, the most powerful electric aircraft with most battery capacity on board.”
He declined to disclose just what that capacity is (it is a race secret), nor did he disclose the aircraft’s “very high glide ratio” other than to say it’s more than 30 at cruise speed (100 mph). These and other aircraft details will be released at the competition, he said.
Pipistrel, founded by CEO Ivo Boscarol, has been producing light aircraft for 20 years in Slovenia, with more than 1,000 completed overall. Pipistrel aircraft have done very well in previous efficiency competitions, including the 2007 CAFE/NASA Personal Air Vehicle (PAV) Challenge and the 2008 CAFE/NASA General Aviation Technology Challenge Centennial Challenge where the Pipistrel Virus SW claimed victory two years in a row.
Before the start of the NASA GFC competition in September, where the G4 will attempt the third consecutive victory, the aircraft must accomplish 40 hours of test flights under the supervision of the head of the Race team, prof. dr. Jack Langelaan.
For more information: Pipistrel.si