Dassault assembles first Falcon 7X trijet

 - October 3, 2007, 10:56 AM

Dassault Aviation has completed assembly of the first Falcon 7X business jet and is aiming to fly it in March. The construction process for the Falcon 7X took just seven months, about half the time it took the company to build the first example of its current flagship, the Falcon 900EX. The manufacturer was aiming to have the aircraft powered up by the end of last month, with a view to conducting a ground run by year-end.

The company attributes the shortened design/build time to new-generation digital design and manu- facturing software, and Dassault is now so encouraged that it feels
that the development of new Falcons could be more economically viable than it would have been with older design/build tools.

Dassault now estimates that costs for developing the 7X could prove to be 20 to 50 percent less than for previous Falcon programs, thanks to the success of the “virtual plateau” concept built upon the latest software from its Dassault Systèmes division. Olivier Villa, senior v-p of civil aircraft, said that the cost reductions could be even more significant to the economic case for a new jet smaller than the 7X.

But this advance alone will not prompt Dassault to launch any new project. “We will do a new jet only when we are sure we can offer something that adds to what is already available, and sure that what we offer to the market doesn’t deceive anyone,” Villa told AIN.

What Dassault is now offering in the $37 million 7X is a 5,700-nm-range trijet with 1,552 cubic feet of cabin volume (25 percent more than the 900EX). The aircraft also boasts an entirely new wing, promising a 30-percent improvement in aerodynamic efficiency (in terms of lift/ drag ratio), derived from a 44-percent increase in area and a 5-percent increase in sweep angle.

According to 7X program deputy director Vincent Oldrati, the larger Falcon has retained the family’s strong airfield performance. Despite weighing 30 percent more than the Falcon 900EX and carrying 40 percent more fuel, the 7X, with its all-new wing, should be able to match the flight profile of its predecessor. Carrying eight passengers and full fuel (NBAA IFR reserves), the aircraft can take off from a 5,200-foot runway (sea level, 15 degrees C), climb directly to 41,000 feet and fly 5,700 nm at Mach 0.80 before landing on a 2,350-foot strip (at 104 kias). Target range at Mach 0.85 is 5,000 nm.

Dassault is aiming to achieve 7X direct operating costs that are no more than those of the 900EX. It also expects that the new model will achieve a 12-percent reduction in maintenance downtime and a dispatch reliability rate of 99.8 percent.

Three 6,100-pound-thrust Pratt & Whitney Canada PW307A turbofans power the aircraft. The company expects the engines to benefit from the 1.3 million flight hours the PW300 line has logged and to have improved maintenance intervals of 3,600 hours for the hot section inspection and a 7,200-hour time between overhaul.

Dassault engineers have been paying close attention to support issues throughout the digital design process. They have used the Catia system to perform three-dimensional validations of parts-access procedures using mannequin technicians. As a result, they have incorporated new access doors into the design.

The new PW307A has already completed 2,100 hours of ground testing and more than 300 airborne hours on a pair of flying testbeds. It is expected to complete certification in the second quarter of next year.

First Fly-by-wire Business Jet
The Falcon 7X, which Dassault claims to be the only 100-percent-new aircraft currently in the business aviation marketplace, is also the first purpose-built business jet with fly-by-wire (FBW) controls. The Airbus Corporate Jetliner also features fly-by-wire controls, but it inherited the technology from the A320 line of single-aisle airliners from which it is derived.

Dassault, which has about 25 years of FBW experience with its fighter programs, has been refining the sidestick-controlled system for the 7X on its Falcon simulation bench. By the middle of last month it had assembled a full system configuration with real pedals and throttles linked to the Honeywell Primus Epic avionics suite. The company will soon integrate the avionics suite with the program’s global test bench, with the addition of real actuators and hydraulics to provide a full iron bird.

Villa said that any new business jet development from Dassault would likely feature FBW controls. He said that with an airplane smaller than the 7X, this could prove more of a design challenge due to the weight penalties associated with the redundancy requirement for extensive computer hardware to “host” the system.

With a predicted average interior sound level of 52dBSIL, the 7X cabin is expected to be four decibels quieter than that of existing Falcons. Oldrati emphasized that, relatively speaking, this is a significant reduction that has been achieved without adding to aircraft weight.

The company has achieved the noise reduction after a seven-year research effort that has resulted in new acoustic shell panels, new definitions and layouts of acoustic materials and improved sound insulation bags. The noise reduction carries a lower weight penalty than it would have in previous models, having required approximately 220 pounds less material than would have been necessary to achieve the same sound level in the 900EX cabin.

The additional space of the 7X has been apportioned to all areas of the cabin, which is 15 percent longer than that of the 900EX. There are three lounge areas and
the aircraft will have a standard forward lavatory, in addition to the aft lavatory. The cabin has 28 windows, which are larger and offer 40 percent more natural light than those in the EX. Maximum cabin altitude will be 6,000 feet (2,000 feet lower than in current Falcons).

The 7X will feature a new cabin management system, including a fully digital entertainment system offering improved video and audio output. Dassault expects to name the supplier soon.

Virtual Plateau: All Players on the Same Level
The comprehensive digitization of the Falcon 7X design and construction process has gone much further than just Dassault’s own engineering. The key to its success has been the airframer’s insistence that all program partners invest in the latest versions of the Catia and Dalmia software so that they can quite literally be on the same page.

In addition to powerplant provider Pratt & Whitney Canada and avionics house Honeywell, the main airframe partners for the 7X are EADS-CASA (Spain), horizontal stabilizer; Latecoere (France), rear fuselage; EADS Socata (France), main fuselage upper section; Sonaca (Belgium), leading-edge slats; and Stork-Fokker (the Netherlands), spoilers, flaps and ailerons. Dassault manufactured all other parts of the fuselage and wing.

In the first phase of the program, 400 professionals from 27 countries gathered in Dassault’s St. Cloud headquarters near Paris to lay the foundations of the aircraft’s design, which was frozen last December. Using 250 Catia workstations and 220 personal computers, they developed a virtual plateau–a detailed database consisting of 100,000 separate aircraft parts, 300,000 brackets and 12,000 wires. A virtual-reality facility was used to evaluate in detail particular facets of the design.

The key accomplishment of this approach has been to obviate the need to build either a mock-up of the 7X or a prototype aircraft. Three fully conforming production aircraft will be used for the flight-test program and a fourth will be used for structural tests on the ground.

Using the digital design and its Dalmia production software, Dassault was able to task robots to pre-drill all parts before the assembly stage. Assembly is being conducted on much simpler tooling than that required for previous aircraft, with parts being put together with adhesives before the installation of rivets into the pre-drilled holes.

According to Biarritz plant vice president Jean-Michel Estrade, all parts and fuselage sections for the first 7X fit together perfectly, the first-time, eliminating the need for
time-consuming adjustments and validating the accuracy of the virtual plateau. Because fuselage sections can be installed from just three or four fixed points, the cost of jigs and tooling has been reduced by about half.

Each day during the assembly of the first 7X, engineers used the virtual-reality center to review the installation of each and every system, explained Falcon v-p of industrial operations Robert De Rocquigny. Dassault purposely delayed starting work on the wiring and piping until April, until the design had been fully reviewed for any necessary changes. Fewer than 100 clashes between parts were found during the assembly of the first 7X, resulting in minimal design changes at this stage.

Dassault Falcon Jet’s completions center in Little Rock, Ark., has been part of the digital design process since the beginning and the interior units for the first two aircraft are already well under way and will be finished to the customers’ specifications before the green aircraft depart the manufacturer’s Bordeaux-Merignac final assembly line. Jet Aviation’s completions facility in Basel, Switzerland, has also invested in the Catia design package so it can take on 7X interior contracts.

Certification and first deliveries of the 7X are scheduled for the final quarter of 2006. The company reports orders for “slightly more than” 40 copies of the new trijet and the next available delivery slot is in the second half of 2008. The customers are drawn largely from the U.S. and Europe and are all existing Falcon operators.