$1.35 MILLION WINNER
Reviewing the Taurus G4
BY MARINO BORIC
N OCTOBER 3, 2011, NASA presented a $1.35 million
check to Pipistrel-USA.com. The team earned
that prize because its electric-powered, purpose-built, four-seat Taurus G4 aircraft won the
Comparative Aircraft Flight Efficiency (CAFE)
Green Flight Challenge (GFC), a NASA Centennial
Challenge program.
The 2011 GFC, sponsored by Google, marks an important and
historic achievement in aviation—the first practical demonstration
of a cross-country, emission-free flight. Pipistrel-USA.com’s
winning G4 flew 195.9 miles nonstop while achieving the equivalent
efficiency of 388.4 passenger miles per gallon (pmpg). Compared to
the fuel efficiency of today’s modern airliners at 91 pmpg (Boeing
747-400), the G4 looks great. Even the economic and fuel-efficient
Toyota Prius automobile, according to U.S. EPA estimates, averages
46 mpg with four onboard, which equals 184 pmpg.
Pipistrel, a Slovenian light-sport aircraft (LSA) manufacturer,
built the G4 by mating two of the company’s Taurus G2 glider fuselages connected with a 15-foot mid wing on which the powerplant is
mounted. The 145-k W electric motor and a controller also were purpose-built for the aircraft.
Pipistrel was established in November 1987 as Slovenia’s first privately owned aircraft production factory. It’s located on the airfield
of Ajdovscina. The company and CEO Ivo Boscarol first built trikes
in 1989 and followed with the Sinus (pronounced see-nus)
three-axis aircraft in 1995. Altogether Pipistrel has manufactured
around 600 trikes and 550 conventional aircraft; yearly production
has ranged from 88 to 92 aircraft.
Pipistrel is currently manufacturing five aircraft models: three
motorgliders—the Taurus M/Electro, Apis/Bee, and Sinus 912—plus
two conventional three-axis airplanes—the Virus 912 (pronounced
veer-us) and Virus SW. A new sixth model, the Alpha Trainer, is
almost ready to fly. It is developed specially for LSA flying schools;
fully equipped and ready to fly, it is expected to cost less than
$80,000 U.S.
A seventh model, the Pantera, is likely to fly by February 2012.
The sleek four-seat low-wing breaks with the Pipistrel tradition of
high/mid-wing airplanes only. According to Pipistrel, Pantera will be
certified in the standard category, will cruise at 200 knots burning
only 10 gallons per hour, and should have a 1,000-nautical-mile
range with full payload. It is powered by the new 210-hp Lycoming
IO-390 engine.
Pipistrel also is offering a plug-and-play electric propulsion system. The system contains everything needed to power an airplane,
including the 40-k W electric motor, power controller/inverter, battery system ( 4. 75 k W and 7. 10 k W), airborne charger, cockpit
instruments, wiring, and even a proprietary propeller. Pipistrel also
developed the Solar Trailer, a transport trailer for the Taurus motor-glider that can charge the aircraft’s batteries in five hours via built-in
solar panels.
