By Matt Harris

Pushing Ahead: Dassault pressing hard towards final certification for its Falcon 7X

At the start of 2007, Dassault Aviation will be anticipating certification and first deliveries of its Falcon 7X tri-jet. Doubters beware: The French planemaker has enjoyed a year of progress in its journey to bring its revolutionary new business jet to market.

Since our last 7X update in May 2005, the business jet’s pioneering fly-by-wire system has proven itself to have excellent handling qualities (as predicted by the simulator), and engine control is said to be precise, with great acceleration; speeds up to Mach 0.92 have been achieved on the test program; the aircraft has reached altitudes of 51,000 feet; and the structure and fatigue test vehicle has exceeded 20,000 simulated “flight” hours en route to 40,000 hours (two times the life of the aircraft).

Meanwhile Dassault has received more than 80 firm orders for the Falcon 7X, that makes the new tri-jet the French company’s most successful pre-certification aircraft to date. There are currently 30 aircraft in various stages of production with s/n 007 in final assembly. The next available delivery position is in early 2010 – so if you’re thinking of joining the queue, do so quickly, as it’s only going to get longer. Indeed, production will increase to three airplanes per month during the second half of 2007 to accommodate the demand for the jet.

When we last looked at the Falcon 7X, it had yet to get off the ground, although s/n 001 had just been presented to a crowd of almost 800 guests at the jet maker’s Bordeaux-Merignac facility, and was engaged in ground run tests.

A year of milestones

2005 was dubbed by Dassault as a year of milestones for several of its Falcon programs – but arguably the most significant was the first flight of the Falcon 7X on May 5th 2005.

Barely had the celebrations of that first flight died down, before Dassault gave a clear demonstration of its confidence in its jet, when, just 15 flights later, it starred with the likes of the double-decker Airbus A380 in eloquently flying above Le Bourget on the first three trade days of the Paris Air Show last June – representing a promise fulfilled by the planemaker.

By the time July was though, the company was flying a second 7X (s/n 002) as its test program gained pace. Immediately after first flight s/n 002 was then ferried to Dassault’s flight test center in Istres, France, where it has primarily been used for systems certification. After the initial first flight, Philippe Deleume, Falcon chief test pilot observed that the second aircraft was responding and flying exactly as the first upholding this as further proof of the extraordinary job Dassault engineers had done in designing this revolutionary aircraft.

At the same time, Dassault was also reporting that the flight envelope on the testing program had continued to expand, with MMO (0.90 mach) and VMO (370 KIAS) reached – further demonstrating that the Falcon 7X program was picking up in pace.

True to Dassault’s promise, first flight of the third test-plane (s/n 003) was heralded in September 2005, to be primarily used for avionics, systems and cabin comfort (noise level and air conditioning) testing. By fourth quarter 2005, the Falcon 7X test planes had exceeded 100 flights, with test pilots Jean-Louis Dumas and Dominique Chenevier reporting excellent control characteristics, despite the rigorous out of envelope test conditions. “We flew the aircraft all the way down to 85 knots,” remarked Chenevier, and were very impressed by the ease with which the aircraft responded to control inputs. It means the aircraft will be very flexible and allow high performance on short airfields.”

First transatlantic crossings

At about the same time that flight number 100 was reported, aircraft s/n 003 was exhibited at the annual NBAA Convention in Orlando, Florida, having made the first transatlantic flight for a 7X aircraft. According to John Rosanvallon, president and CEO of Dassault Falcon Jet, the trip proved well worthwhile, having brought about a hugely “gratifying” reaction from eager attendees. “The new technology of the airplane, particularly the flight deck with its fly-by-wire flight control system, drew a constant crowd of admirers,” he remarked.

The return trip from Orlando to Istres provided the ultimate test of cabin comfort, according to Yves ‘Bill’ Kerherve, Dassault’s senior chief test pilot. Specifically, the new pressurization system, which provides a 6,000-foot cabin altitude, and the advanced temperature control system achieved the grade. “On such a long-distance flight, (nine and a half hours) the crew and five technicians aboard were able to appreciate all the advance planning we’ve done to make the cabin extra comfortable.”

Design enhancements

During that NBAA Convention, Dassault announced that ongoing design enhancements (currently being tested) could increase the range of the airplane close to 6,000nm from an original projection of 5,700nm.

Olivier Villa, senior vice president of Civil Aircraft at Dassault Aviation explained, “Over the past several years, I’ve had the opportunity to meet a lot of Falcon 7X prospects and customers… It was clear that some of them wished to have additional margins to perform their missions in adverse weather conditions and without payload limitations. We decided to increase the aircraft range and payload capacity in order to meet and exceed their additional requirements.”

In addition, Dassault announced the payload capacity of the 7X was to be increased and additional fuel tanks were installed in the forward section. To accommodate the increased MTOW, thrust for the Pratt & Whitney Canada 307A engines were increased from 6,100 lbs per engine at ISA +18°C to 6,400 lbs at ISA +18°C.

This was made possible by contractual margins already established at the beginning of the design phase for the airplane. Engine performance targets have since been confirmed and Dassault says the changes will have no impact on the maintenance time between overhauls.

In addition, tentative wind tunnel studies of the 7X with winglet designs were conducted and once the range figure was raised, Falcon 7X s/n 001 began test flying various winglet designs during the fourth quarter last year. Flight tests confirmed the winglet benefits especially during long-range flights, thus the winglets were incorporated (to be designed by Dassault, and manufactured in the Biarritz, France facility). “We could not be more pleased with the design and performance of the wing,” added Villa.

Other modifications to occur, included the removal of a secondary rudder on the lower fin section of the tri-jet to allow a more optimized shaping of the fin, which, in turn, allowed simplification of the fly-by-wire system. The updated fly-by-wire system was thereafter frozen along with the new lower fin shape.

The bleed air system was also redesigned to regulate the bleed air temperature below 200°C in an effort to meet an unanticipated request by the authorities. This was achieved by adding one independent pre-cooler per engine. Subsequent tests on s/n 002 showed nominal temperature regulation from the pre-coolers. Also, a complete redesign of the slats anti-ice system has been completed with performance evaluations ongoing. Installation of the improvements were also incorporated into s/n 001 and s/n 003.

Following further testing, final specification and performance figures were due to be confirmed at the time of press.

As Dassault continues to press on towards it’s goal, Falcon 7X s/n 003 will fly to Istres Test Base after a two months completion work.

Airplane s/n 002 successfully completed its cold soak campaign in Resolute Bay, North Canada as we wrote this feature.

In addition, anti-icing tests have begun, and tests for landings on a contaminated runway will commence in Istres around mid-May, while flight test certification will start during the summer.

As mentioned above, final certification is expected to take place in early 2007 – following approximately 1,200 flight hours – with first deliveries beginning shortly after that. The FAA and EASA have both accepted all systems architecture for the jet as certification for the aircraft continues to progress well.

As confirmed by Rosanvallon: “While we’re testing enhancements and working with the authorities, the Falcon 7X program is continuing at a rapid pace.”