EAA Sport Aviation

WALKING DOWN the flightline, the E-Flight Waiex won’t turn any heads. It’s the same tried and true airframe that Sonex Aircraft LLC has been producing since the late ’90s. It’s what’s under the cowling and in the cockpit that’s special. Because it is a proven aircraft design with a new powerplant, EAA’s editorial team crowned it the Class of 2011’s Most Likely to Succeed. We feel it will prove to be another example of the homebuilt community experimenting and developing viable new technologies that will eventually make their way into certified aircraft.

In December 2010, the E-Flight Waiex made its first flight, marking a critical step in developing a proof-of-concept electric motor powerplant, controller, battery pack, and

THE ELEKTRA ONE is more than a single-seat, electric-powered aircraft from German company PC- Aero. It’s a complete concept with a solar hangar that will recharge the aircraft’s batteries. The company said the aircraft-hangar combination would come on the market for less than € 100,000 (around $145,000).

Calin Gologan, PC-Aero CEO and developer of the Elektra, said, “This is the future of leisure aviation as a bridge to the next step: electric transportation.” With this integrated approach, our editorial team deemed this project the Most Visionary in the Class of 2011.

MOST LIKELY TO SUCCEED

charging system. Sonex first announced its E-Flight Initiative at EAA AirVenture in 2007, with the goal of installing its electric powerplant in an airframe optimized for the power system called ESA (for Electric Sport Aircraft).

The system includes the E-Flight 54-k W brushless DC electric motor, electronic motor controller, a 14.5-k W/h lithium-polymer battery system, battery management system, and cockpit instrumentation and controls. Flights with the v3.0 motor will continue into early summer to evaluate the total power and maximum duration for that motor, controller, and battery combination as well as to compile data on the charging capabilities. Sonex is finalizing control systems for a fourth iteration of its electric motor. The design will have more sophisticated control systems.

CEO and General Manager Jeremy Monnett said the company’s advantage is in its use of already proven components such as the airframe and propeller. It also owns all of the components of its electric powerplant, helping keep costs down when it comes time to establish pricing for the aircraft. The company plans to begin testing and flying the v4.0 motor in July but won’t begin work on an optimized airframe until it is completely satisfied with the powerplant. Only once everything comes together will Sonex begin to talk pricing and availability.

MOST VISIONARY

The Elektra One made its first flight on March 19 with Jon Karkow, lead aero engineer for ICON Aircraft, at the controls. Karkow flew to an altitude of 500 meters ( 1,640 feet) at a climb rate of 400 fpm and said the aircraft was stable and had good control and landing characteristics. Norbert Lorenzen, PC-Aero’s primary test pilot, also was impressed with the good flight performance despite the low engine power. “The acceleration with the 16-k W motor was surprisingly good. The handling and response was very good. In the air it feels most like a glider,” Lorenzen said.

PC-Aero claims the aircraft will provide more than three hours’ flight endurance with a range of more than 400 kilometers (about 250 miles). The electric drive system, including a 13.5-k W (continuous/16-k W maximum power) brushless electric motor, controller, battery management, and three-blade propeller comes from Geiger Engineering of Germany. The airframe is made from lightweight composites and weighs in at 100 kilograms (220 pounds) empty, including the motor. The landing gear is a single, center wheel, and the takeoff distance is 150 to 200 meters (about 500 to 650 feet), according to Lorenzen. The aircraft will soon get a new variable-pitch propeller and a retractable gear.

The Elektra One is in the German Ultralight LTF-UL-cate-gory with certification expected by the end of the year.

PHOTOGRAPHY COUR TESY OF SONEX AIRCRAFT AND PC-AERO

AIRCRAFT DATA

AIRCRAFT MAKE & MODEL: Sonex E-Flight Waiex

LENGTH: 18 feet, 1 inch WINGSPAN: 22 feet HEIGHT: 51 inches

MAXIMUM GROSS WEIGHT: 1, 100 pounds EMPTY WEIGHT: 861 pounds SEATS: 2

POWERPLANT MAKE & MODEL: E-Flight 54-k W electric motor BATTERY: 14.5-k W/h lithium polymer pack HORSEPOWER: 73 ( 54 k W) PROPELLER: Sensenich fixed pitch wood CRUISE SPEED: TBD VNE: 197 mph VSO: 40 mph

FOR MORE INFORMATION: www.SonexAircraft.com/research/e-flight

AIRCRAFT DATA

AIRCRAFT MAKE & MODEL: PC-Aero Elektra One

WING SPAN: 28. 2 feet ( 8. 6 meters)
WING SURFACE: 21 square feet
( 6. 4 square meters)
MAXIMUM WEIGHT: 661 pounds
(300 kilograms)
EMPTY WEIGHT (WITHOUT BATTERIES):
220 pounds ( 100 kilograms)
SEATS: 1