2000EX on target despite sfc and weight gains

 - January 7, 2008, 10:29 AM

Higher-than-expected engine fuel consumption is causing a six-month delay, to this March, in certification of the Dassault Falcon 2000EX. According to the French manufacturer, the increased fuel consumption of the Pratt & Whitney Canada PW308C turbofan has also prompted an increase in the airplane’s fuel capacity and mtow to preserve range guarantees. Delivery plans remain on schedule.

“The Falcon 2000EX had a very ambitious certification program, and the development has been somewhat more difficult than expected,” aircraft program manager Jean-Louis Cuvillier told AIN last month. Certification was initially pegged for the third quarter of 2002 but has slipped by half a year. This time has been used to make aircraft modifications. Dassault had to add 690 lb in fuel capacity–a 4-percent increase over the initial design capacity of 15,970 lb–to meet the guaranteed range. “This translates into a 600-pound increase in mtow to 41,300 pounds,” Cuvillier said. A 42,200-lb mtow is available as an option. Balanced field length remains within specifications, at 5,590 ft, in spite of the higher mtow. NBAA IFR range (full fuel, six passengers, two crew, Mach 0.80) remains 3,800 nm.

“We’ve had challenges on the PW308C,” Pratt & Whitney Canada chairman Gilles Ouimet, acknowledged, adding that target performance was “very aggressive when compared to other engines in the PW300 family.” In fact, as early as fall 2001, when flight tests began on P&WC’s Boeing 720 flying testbed, specific fuel consumption (sfc) at altitude appeared to be higher than expected, Ouimet told AIN. He explained: “Several components, such as the high-pressure compressor and turbine, came short of their targets, which led to a gap in terms of sfc.”

P&WC and Dassault then started looking for ways to make the aircraft-engine combination meet its objectives. The Longueuil, Quebec-based engine manufacturer finally increased the PW308C’s thrust in climb conditions. “It was important to reach the initial cruise altitude of 41,000 ft as quickly as possible to save fuel,” Ouimet said.

The PW308C was nevertheless certified on Nov. 29, 2001. P&WC intends to continue working on the PW308C and improve it “until the engine is as good as it can be.”
Apart from the engines, “few things needed extensive flight testing,” Cuvillier said. However, he cited the anti-ice system development as another cause for the delay. “We took some margin and customer deliveries will not be affected,” a company spokesman added. Dassault still plans to deliver the first Falcon 2000EX in April, right on schedule.

According to Cuvillier, cabin noise level held a pleasant surprise. “In the frequencies the human voice uses for conversation, the noise level is two decibels lower than in the Falcon 2000,” he said. New thrust reversers work as expected, he said, with a Nordam “advanced single-pivot” design. Triple redundancy (mechanical, electric and hydraulic) of that system made in-flight deployment trials unnecessary.

Two aircraft are involved in flight tests. Number one is fitted with test instruments and is being used for all manufacturer tests, the climate tests and most certification tests. Number two has a complete cabin layout and has been used for comfort tests (cabin noise and temperature), as well as for endurance tests. They have been flying since Oct. 25, 2001, and April 18, 2002, respectively.

“Our first test article has logged 115 flights and 260 flight hours, whereas the second one has logged 50 flights and 17 flight hours,” Cuvillier told AIN. Flight tests should last until the end of this month. December and January tests include endurance, engine operability and hot-weather evaluations, the last-mentioned in Djibouti, western Africa.

Production of 2000EXs at Dassault’s Bordeaux Mérignac facility is well under way, with a planned production rate of three aircraft a month this year. However, fractional provider NetJets will not get any of the first batch of 2000EXs, as it has ordered those with the new EASy flight deck. This version will be available from Falcon 2000EX number 33, to be delivered in April next year. The first 32 copies will get the Falcon 2000’s Collins Pro Line 4 avionics.

Dassault declined to disclose its order book for the 2000EX, but the biggest single order came from NetJets in April 2001 for 25 twinjets with options for 25 more. In July 2001, Dassault Falcon Jet president John Rosanvallon said the company expects eventually to sell about 250 copies of the 2000EX.

The new Falcon is essentially a re-engined and longer-range version of the Falcon 2000, providing 3,800 nm vs the earlier airplane’s 3,040 nm. On the Falcon 2000EX, a front and rear center tank augment the original Falcon 2000’s central and wing tanks. The fuel system also features a new fuel-quantity management computer from Intertechnique. The Falcon 2000EX was launched in October 1999 but not formally announced until October 2000. The first iteration was rolled out at the Bordeaux Mérignac facility on July 19, 2001.

The Falcon 2000EX EASy sells for about $25 million, about $2 million more than the Pro Line 4-equipped model. It competes head-to- head with the Bombardier Challenger 604 and the Gulfstream G300.