Longer, faster 7X

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After basing an entire family around the Falcon 50's super-critical wing, Dassault has come under pressure from the market for longer range and faster flight since the mid-1980s, says Jean Rosanvallon, president of Dassault Falcon Jet.

Initial studies resulted in the Falcon 50EX, which, re-engined with Honeywell TFE731-40 turbofans, increases maximum speed to Mach 0.80 from M0.75. This was, however, a stopgap. Last year Dassault unveiled plans for the new 7X (Flight International, 6-12 November, 2001). With a range of 10,550km (5,700nm), the 7X will fly 26% further than the Falcon 900EX, but is still behind rivals the Bombardier Global Express, at 11,130km, and Gulfstream V, at 12,046km. But Rosanvallon says that when the company analysed all the major city pairs, it found that 10,000km was ample for most typical journeys.

Dassault says that speed and fuel efficiency are more important, but the 7X's maximum speed at Mach 0.9 is only fractionally faster than M0.88 for the GV and the Global Express. With a maximum difference in cabin width of only 0.3m (12in) between the three, Dassault is betting heavily on its wing aerodynamics giving it the edge. The 7X is Dassault's largest aircraft and has a new "high-transonic" wing, and a higher sweep and aspect ratio than the current Falcon wing. Dassault claims that this optimised shape (both aerofoil and planform) improves the lift-to-drag ratio by a factor of more than 10, while maintaining sufficient fuel volume. Use of a third engine means that the 7X will maintain a low approach speed necessary for short take-offs and landings.

Rosanvallon says that the new wing will underpin the entire Falcon range for the next 30 years. The company holds over 40 deposits on the trijet, which is likely to sell for $37 million and be certificated in mid-2006, with first delivery later that year.