Eclipse To Modify All Model 500s To Boost Performance
When it became clear during development of the Eclipse 500 very light jet that it wouldn't quite be able to meet its projected speed and range targets, the depositors were offered refunds. But the company also said it would continue working on aerodynamic improvements. On Tuesday, Eclipse CEO Vern Raburn said a series of modifications have improved performance to 370 ktas and an NBAA IFR range of 1,125 nm (with 100-nm alternate). And, despite an earlier announcement that the first 100 Eclipse 500s would meet a lower standard -- 360 knots and 1,055 nm -- all of those twinjets now will be upgraded to meet the new performance numbers, Raburn said. A handful of changes, from bigger tip tanks to slicker aerodynamics, have resulted in the improvements. The new tip tanks will add 25 gallons of fuel. Changes to reduce drag on the airframe include a new tail fairing, main landing-gear fairings and covers over the control-surface hinges. The elevator and rudders have been extended to eliminate gurney tabs that added significant drag. This change also improved the control forces, Eclipse said in a letter to customers. The Full Authority Digital Engine Control (FADEC) software will be changed to improve thrust at cruise altitudes from 25,000 feet through the certified max altitude of 41,000 feet. This won't increase the 900-pound-thrust rating of the Pratt & Whitney PW610F turbofans, but results in more thrust at typical jet cruise altitudes, the letter said.