Playing the percentages, Dassault reveals Falcon 7X

 - May 22, 2008, 5:07 AM

Dassault Falcon Jet describes its new 5,700-nm, $35+ million Falcon 7X three-engine business jet as providing 30 percent more range and 20 percent more cabin space at a 10 percent higher price than the 900EX. This positions the new airplane in the range and price market between its own 900EX, the Gulfstream IV-SP and the newly announced Global 5000 on one side and the GV and Global Express on the other. Is Dassault concerned that the 7X could eventually dent or even destroy the market for the 900EX? The company cavalierly responded, “Our best competition is ourselves.”

As reported last month in AIN (page 26), the Falcon 7X is the first of what Dassault said is a “new generation” family of business jets that will include both smaller and larger versions, twins as well as trijets. The company said the 7X will “fly faster, farther and higher” than any previous or current Falcon. The number seven was selected because it’s a lucky number “and allows plenty of room to scale up and down for future derivatives.” The “X” was tagged on to add an air of mystery and to “telegraph the advanced nature of the airplane,” explained Dassault.

The airplane’s performance numbers, as previously reported, stem from a new wing with a higher aspect ratio (ratio of the chord of the wing to its span), more sweep and transonic optimization to provide a 30-percent improvement in aerodynamic efficiency over current Falcons, Dassault said. Transonic optimization, explained the company, “involved delaying the onset of Mach buffet, allowing high cruise speeds [up to Mach 0.90] without steep drag rise.”

The new wing will have at least one characteristic familiar to all Falcon wings: it will be clean of “add-on” devices such as winglets, stall fences and vortex generators. Current Falcon wings are derivatives of the Falcon 50 wing designed in the 1970s.

Dassault said full deployment of flaps, slats and slots “yields three times more lift than in cruise flight,” enabling the Falcon 7X to have an approach speed of 104 kias, five knots slower than that of the smaller 900EX, and a landing distance as short as 2,350 ft. Slat deployment is automatic at high angles of attack. Maximum landing weight is within 3,200 lb of mtow. Fuel will be carried in both the wings and the fuselage. TRW will provide the hydromechanical flap and airbrake systems, in addition to the airplane’s electrical system.

Amenities in the more than 41-ft-long cabin (about the same as a GIV-SP’s) are intended to provide passenger and crew comfort for nonstop flights close to 13 hr. The standard 10-place interior will be divided into three distinct passenger seating areas with fore and aft lavatories and added galley space (see accompanying diagram). Six seats will be completely berthable. A crew rest area adjacent to the forward lavatory is an option, as is a cabin humidifier. Cockpit seats will recline.

New or upgraded environmental systems will provide better temperature control and average sound levels are expected to be in the 50- to 52-dB SIL range, without optional soundproofing. The pressurization system’s 10.2-psi differential will provide a cabin altitude of 6,000 ft, 2,000 ft lower than that of any other Falcon. Most long-range trips will be flown at 45,000 ft, according to Dassault.

First FBW for a Bizjet

The Falcon 7X will be the first traditional business jet to have fly-by-wire (FBW) and sidestick controls. Claimed benefits of FBW are “precise flight path control, automatic trim adjustments during configuration changes and basic autopilot functions through the side-stick for setting heading and [pitch] attitude.” Pilots will also be able to extract maximum performance (maximum angle of attack, for example) during wind-shear encounters or collision avoidance maneuvers “without concern for overstressing the airplane or stalling.”

With FBW, there is no direct and constant relationship between pilot control input and control-surface deflection. Instead, the pilot’s sidestick communicates first with a computer. A deployable ram-air turbine will provide backup power for the FBW (see article on next page for more on the Falcon 7X FBW system). The 7X will also have a brake-by-wire system, provided by Aircraft Braking Systems. That Akron, Ohio company will also provide the airplane’s wheels and carbon brakes.

Major systems suppliers include Honeywell for the avionics and Pratt & Whitney Canada for the PW307A turbofans. The Honeywell system will comprise the Primus Epic suite integrated with Dassault’s new EASy flight deck, which includes a cursor control device for data input. The EASy cockpit is scheduled to start flight tests early next year (see AIN, July, page 104 for a detailed description of the EASy cockpit). Honeywell will also supply the APU, air management system and hydraulic power generating system.

On the new-generation Falcons, starting with the 7X, pilots will look out of four curved windshield panels, a major departure from the Falcon’s traditional seven-pane arrangement. Twenty-eight windows line the cabin of the 7X. Each window is larger than those on current Falcons and positioned to give passengers better viewing angles. The windshield and windows will be provided by subcomponent manufacturer Sully Saint Gobain.

With the Falcon 7X, P&WC makes its debut on a Dassault Falcon trijet with its flat-rated 6,100-lb-thrust PW307A, one of the PW300 family members. PW300 versions also power the new Falcon 2000EX, as well as the Hawker 1000, Gulfstream 200 and Learjet 60. The PW300 series has also been selected to power the new Citation Sovereign, Hawker Horizon and Fairchild Dornier Envoy 3. As with all Falcon trijets, the center engine will have a thrust reverser. The reversers and engine nacelles will be built by Hurel Dubois and Aermacchi.

The Fadec-equipped engine will enter service on the 7X with a 7,200-hr TBO, and Dassault expects Falcon 7X initial operations to have a mission reliability rate of 99.8 percent.

Additional suppliers for the 7X include Messier Dowty (landing gear), Intertechnique (oxygen), Parker (hydraulics), Goodrich (air data), L’Hotelier (fire detection and extinguishing), EADS Socata and Latecoere (fuselage sections) and Sonaca (wing leading edge).

Why 5,700 nm?

Dassault selected 5,700 nm based on where most international companies are located and on their travel patterns. “When we analyzed all major city pairs and ran them against corporate requirements, the decision was easy,” maintained Dassault. Eastbound out of Paris, for example, 5,700 nm delivers Tokyo, Beijing and Johannesburg, South Africa; Paris westbound gives operators nonstop flight to Los Angeles, Mexico City and São Paulo. From New York, the Falcon 7X reaches all of Europe, all of South America and Riyadh, Saudi Arabia. Westbound from New York, the new jet can make Honolulu and Petropavlosk, Russia.

Dassault expects to start 7X flight testing in 2005 and receive type certification (along with RVSM approval) in 2006, with deliveries following later that year. At press time the company claimed it had letters of intent for 41 airplanes, split about evenly between U.S. and non-U.S. customers. All the customers to date are corporate (as opposed to fractional-ownership operating companies).

Some of this discussion about the 7X will no doubt take readers back to the NBAA Convention in 1992 when Dassault said its design for the Falcon 9000 trijet, a concept based on “a new advanced wing and using the same fuselage cross section as the Falcon 900 with seven feet of additional cabin length.” The Falcon 9000 would have been capable of nonstop flights of 6,000 nm. A year later, Dassault suspended development of the 9000, claiming it did not foresee a sufficient market for a third ultra-long-range business jet competing against the Gulfstream V and Bombardier Global Express. The French aerospace manufacturer believes it can sell at least 250 Falcon 7Xs over the next 10 to 12 years.

Despite the similarities between the 7X and the 9000, Dassault said there is no direct connection between the two designs because the airplanes were driven by different design goals. What was driving the 9000 was getting an airplane into the marketplace as soon as possible to compete with the GV and Global Express. To get into that market in a given timeframe, available engines would have been required. The engines available back then were going to have to be pushed about 20 percent to get the kind of thrust needed, according to Dassault.

Wing performance would also have had to leap significantly. Dassault sought to do this by making improvements in laminar flow, a process that at the time would have been complex and expensive. This technology, which included perforations in the wing, was flight tested on a Falcon 50 and a Falcon 900 and would have “probably provided the intended improvements but at an unacceptable cost, both in manufacturing and possibly operational costs,” Dassault said.

The design goal and the intended market for the 7X are “completely different,” Dassault maintained. The objective is to keep costs down: “manufacturing costs, acquisition cost and cost of operations.” According to Dassault, the new wing for the 7X provides about the same efficiency as the modified wing on the 9000 would have had, but at “significantly lower cost.” Thrust requirements are also simpler, Dassault said. The 7X has smaller power requirements and engines that won’t be pushed to their limits. Furthermore, the 9000 was not going to be a FBW airplane.