GUY NORRIS / LOS ANGELES
Computer analysis shows that the executive aircraft will be capable of up to Mach 0.96
Aviation Technology Group (ATG), the Colorado-based company developing the two-seat Javelin executive "sport jet", says initial computational fluid dynamics (CFD) analysis reveals the fighter-like design will be capable of speeds up to Mach 0.96 rather than the M0.92 previously expected.
The CFD tests, conducted by Seattle-based Analytical Methods, validated the high-speed aerodynamics and revised performance characteristics of design changes made to reduce transonic drag. These include the introduction of area ruling by moving the cockpit forward 250mm (10in) and "waisting" the fuselage diameter at the wing junction. Changes to the wing include a thinner section and a 2í increase in leading-edge sweep to 40í. "We have a high-speed aircraft, like Cessna's Citation X, and there is a benefit to be gained from area ruling in the transonic region," says ATG president George Bye. "We've been looking at it very closely on the computer and trying to optimise the shape of the fuselage. We have achieved higher cruise speeds and reduced the drag on the aircraft so the Mmo [maximum operating speed] looks like it will now be M0.96," he adds.
Factoring in the results from the CFD tests, ATG predicts the Javelin will have a 51,000ft (15,550m) ceiling, a range of 2,780km (1,500nm) and cruise speed of up to 530kt (975km/h). With a pressurised cockpit, the company says the aircraft will be capable of climb rates as high as 70m/s (13,800ft/min) and up to 115m/sunrestricted.
The aircraft, with a maximum takeoff weight around 2,090kg (4,600lb), will be powered by two 1,500lb-thrust (6.7kN) engines. Although the engine choice is under competitive evaluation, Bye says the "front runner" is the Williams FJ33. Based on the FJ44, the turbofan is being baselined for the first two years of Javelin production, adds Bye.
Following completion of a second series of low-speed tests in the University of Washington windtunnel, due to begin later this month, ATG plans to begin assembly of the initial flight test Javelin. First flight is set for November next year and, assuming FAR Pt 23 certification can be achieved in late 2003, first deliveries are scheduled to begin in 2004.
Bye says the high speed and projected low operating cost of the Javelin is attracting "remarkable interest from fractional ownership schemes, as well as a wide variety of Part 125 users, including air freight, charter operators and others". Although Bye declines to say how many $25,000 refundable deposits have been placed, he says: "We have over 95 requests for purchase agreements."
Source: Flight International
