Changes In Wing Design, Flaps, Canopy

Aviation Technology Group, Inc. told Aero-News Wednesday the company has made several design changes to its Javelin two-seat jet aircraft, all with an eye towards making the plane safer to operate. The changes include an increase in wing size, enhancement of wing lift devices, and improvement to the canopy opening mechanism. 

In order to achieve a lower stall speed, designers at ATG have increased the wing span by 1.85 feet, and the wing area by 29 square feet. To allow for slower approaches and landings, the wings were further enhanced with Fowler flaps, and leading edge flaps. Aerodynamicists expect the wing improvements to yield a 5 to 7-knot decrease in stall speed, which would lower the Javelin’s stall speed to 90 knots.

"ATG has always emphasized safety as a priority," said ATG president Charlie Johnson. "And, lower stall speed provides an extra margin of safety during critical takeoff and landing phases.”

Engineers also implemented design improvements to the Javelin's canopy system. Under advisement from ATG’s Pilot-vehicle Interface Working Group, designers selected an aft-hinge canopy opening mechanism to replace the less conventional side-opening arrangement.

Removal of the side hinges gives the new canopy a more aerodynamic profile, enables ground operations with an open canopy in winds up to 40 knots, and allows Javelin pilots to taxi with improved visibility and cockpit ventilation. The new canopy also features a gas spring and electric motor combination, which allows pilots to open and close the canopy with the push of a button.

ATG says these improvements are the last major design changes to the Javelin, freezing its configuration to enable suppliers to start producing the production airframe parts.

Alas, the changes haven't come without a slight performance penalty. ATG says the improvements to the wing and canopy designed have resulted in a nominal weight increase, and a small decrease the Javelin's cruise speed to 500 knots.

After a thorough review and acceptance by ATG engineering staff and executive management, the overall benefits of these final design changes were confirmed by a series of wind tunnel tests conducted at the University of Washington Aeronautics Laboratory in May.

The company reports it is ontrack to begin customer deliveries of the FAA-certified Javelin in 2008.

FMI: www.avtechgroup.com