High Performance Very Light Twin

Spectrum Aircraft Corporation of Florida just introduced the A-36 "Vulcan", a brand new two-seat, twin-engine sport plane. Commissioned by Spectrum, the new Vulcan was designed and engineered by Aeroprakt Ltd., a European sport-aircraft manufacturer with a design team of aerospace engineers from Antonov, the ex-soviet developer of large transport jets.

"We're very pleased with the new Vulcan. Aeroprakt put their heart & soul into the design, while keeping with their very disciplined & scientific engineering approach, " said Spectrum president John Hunter. "The result is a new design unlike any other."

The new sport-twin is a CAD/CAM design (computer aided design/computer aided manufacture), employing the latest engineering software and modern CNC machinery. It is designed with all-metal wings and tail, with a composite forward-fuselage cockpit structure. This results in a high strength-to-weight ratio, optimum aerodynamic efficiency and superior occupant protection. Careful attention was given to maximize outward visibility, and comfort. Two 100 hp Rotax 912-S engines power the 980-pound aircraft.

The A-36 made its maiden flight September 18, 2004 and began a rigorous 6-month flight testing phase.

"As a 'go anywhere' aircraft, the Vulcan was designed for a broad speed range, " said Hunter. "It needed a low stall-speed in order to have superior STOL and rough field performance and the ability to fly slow when you are down low, at tree top level. 'Low and slow' is why it needed twin-engine reliability in the first place. But with 200 hp, we knew its cruise speed could be very competitive against lesser-powered, heavier, general aviation standards like the Piper Cherokee & Cessna 172. We wanted the best of both worlds."

Hunter wanted it to match a Super Cub as a bush plane, yet provide a big improvement in reliability and visibility. The aircraft was designed to have a 42 mph stall speed and a Vh of 160 mph at sea level. He reported that in low level tests, chief engineer and test pilot Yuri Yakolev has reported an indicated stall speed of 38 mph, a maximum cruise speed of 162 mph, and a top speed of 170 mph (in level flight).

"Above all, the A-36 was designed for exemplary single engine performance, which was achieved by coupling close-centerline thrust in a pusher configuration with a high power-to-weight ratio, " explained Hunter. "The concept is well proven by the twin-engine Air Cam and A-26, and the A-36 has a better power to weight than either."

With a gross weight of 1,660 pounds, power-to-weight ratio is only 8.3 pounds per horsepower. The A-36 breaks new ground for sport-twin single engine performance. It was designed to have a single engine rate of climb of 800 fpm and a service ceiling of 15,000 feet.

The initial rate of climb for the twin is listed as 2,200 fpm, and service ceiling is listed as 28,000 feet msl. Standard wing-tank fuel capacity is 32 gallons. Spectrum reports that A-36 will go on sale in the US this fall as a kit plane with an estimated total cost for a completed, well equipped Vulcan of less than $120,000 including a "Horizon" EFIS, EIS digital engine monitors, and Becker transceiver and transponder.

FMI: www.spectrumaircraft.com