The GT4 is striking in outward appearance
Volta Volaré has begun taking orders for its four-seater GT4 hybrid private aircraft it calls “the most technologically advanced private aircraft available anywhere on Earth.” Though the GT4 is perfectly capable of taking off and flying powered only electrically, a gas engine starts when the airplane’s battery drops to 25 percent capacity in order to recharge it mid-flight. Surprisingly, perhaps, Volta Volaré makes a strong economic case for the GT4. Because the powertrain has only one moving part – the motor or “EViation Drive” – the company claims the need for maintenance is reduced significantly, offering increases in TBO (time between overhaul) by up to a factor of ten when compared to a combustion engine.
It also claims that the EViation Drive “delivers more torque and horsepower than any 20th century internal combustion engine,” but since the 21st century is now at least 11 years old, that seems a somewhat arbitrary comparison.
Volta Volaré’s spec sheet makes somewhat confusing reading (an energy storage system sized in kilowatts doesn’t make much sense to me, for instance), but seems to suggest the EViation Drive delivers 220 kW (300 hp), while the “range extension generator” dishes out about 130 kW (180 hp) – though presumably the only use this can be put to is recharging the plane’s batteries.
The performance-based specifications are rather clearer:
- Take Off Distance: 1400 ft (430 m)
- Rate of Climb: 1800 ft/min (550 m/min)
- Landing Distance: 1500 ft (460 m)
- Cruise: 160 knots (296 km/h) @ 12,500 ft
- Ceiling: 24,000 ft
- Maximum speed (sea level): 310 knots (574 km/h) – which makes it significantly faster than the Cessna Corvalis TTX
- Minimum Speed: 65 knots (120 km/h)
- Landing Speed: 75 knots (139 km/h)
Powertrain-wise, I’m more inclined to look at Popsci’s spec reporting following its interview with Volta Volaré CEO Paul Peterson. “The GT4’s electric motor, which is made from the combined cores of two smaller motors, sits in a sealed aluminum housing,” it reports. “It can generate 600 peak horsepower [450 kW] and sustain 400 horsepower [300 kW] throughout flight.”
Popsci additionally reports that the energy storage system consists of a 900-pound (408 kg) lithium-polymer battery comprising 236 cells, which is a significant chunk of the GT4’s overall empty weight of 2,600 pounds (1,179 kg). The battery’s recharged by a 1.5-liter gasoline engine fueled from a 23-gallon (105-liter) tank. Combined these give the GT4 a reported range of 1,000 nautical miles (1,852 km).