Companies Sign Tentative OEM Agreement

Sadler Aircraft Company recently told potential customers a tentative OEM arrangement has been reached with RotaMax Engines to provide an optional 130-hp, Wankel-type twin-rotor powerplant for its upcoming Vampire light sport aircraft.

As ANN reported, the mid-wing, twin tailboom pusher-powered Vampire is based on Bill Sadler's single-seat ultralight design. Around 30 were built in the United States in the 1980s, and the design was also licensed to an Australian Company. Both US and Aussie companies eventually folded.

Fifteen years passed before Sadler unveiled a beefed-up version to serve as an attack and surveillance plane for the Turkish military. Dubbed the Piranha, the plane carried a 30mm cannon, with two hardpoints available to mount up to 1000 pounds of rockets or small bombs. Power was from a 450-horsepower engine, and the plane had retractable gear; it was dropped by the Turkish armed forces in the interest of F-16s.

The Vampire LSA is a heavily- (or lightly-, as it were) modified version of the Piranha. By lengthening the wing, welding the gear in the down position, making some minor changes to the cockpit pod, and scaling WAAAAY back on the power, Sadler was able to bring the Piranha into LSA compliance.

Sadler showed a mockup of the plane at AirVenture 2007. A 100-horsepower Rotax 912S will be the standard powerplant.

Listen To ANN's Special Feature Aero-Cast With Eric Barger, president of RotaMax Rotary Engines

In addition to offering a Made-In-The-USA engine choice to customers, the company notes the RotaMax should also offer greater climb rates, and shorter runway requirements for takeoff.

"Top speed will remain at 138 mph to meet LSA requirements," the company tells ANN. "And we still hope to keep the base price of the Vampire below $85,000."

The company plans to start flight testing of a RotaMax-equipped Vampire by the first week in November, in anticipation of production starting in 2008. Stay tuned.

FMI: www.sadleraircraft.com, www.rotamax.net