MIKE GERZANICS / BORDEAUX, FRANCE
Dassault added the 2000EX to its Falcon family for customers who required transatlantic capability. How does it compare to the 2000?
In the early 1990s, Dassault expanded into the super mid-size business jet segment with its Falcon 2000. Using the same fuselage cross-section as its popular Falcon 900 trijet, the French manufacturer brought to market a twinjet with large-aircraft cabin comfort.
The Falcon 2000 also used the same wing as the 900, providing it with a Mach 0.8 cruise speed. Two Honeywell/General Electric CFE738 turbofans give the aircraft a 5,550km (3,000nm) range. Even considering worst-case winds, the aircraft could connect the most distant of US city-pairs. While the Falcon 2000's combination of size, speed and range was a success, Dassault saw an opportunity to extend the Falcon family further.
Some operators find the Falcon 2000's transcontinental range insufficient for their needs, and desire a transatlantic capability - Paris to New York against prevailing winds. To meet this demand, Dassault chose a low-risk approach, adding fuel capacity and re-engining the 2000. This allowed the company to field a large-cabin twinjet with a 7,040km range - the Falcon 2000EX - in a short time. Launched in October 2000, the 2000EX received US and European certification in March. Flight International was given the opportunity to fly Dassault's long-legged and latest Falcon Jet.
With the exception of the engines and nacelles, the 2000 and 2000EX are almost identical. This was by design, as Dassault tried to keep changes to an absolute minimum. Two additional fuselage fuel tanks, one forward and one aft of the existing centre tank, combine to give the 2000EX a fuel capacity of 7,557kg (16,660lb), an increase of 37% from the 2000. To loft this additional fuel, Pratt & Whitney Canada PW308C engines were selected to power the 2000EX. The new engines each provide 7,000lb (31.2kN) of thrust, 18% more than the 2000's CFE738s. Four fuel boost pumps increase operational reliability over the 2000, which only has two, both of which must be operable for dispatch. Upgraded brakes and modifications to the landing gear round out the changes required to give the 2000EX transatlantic range.
The Falcon 2000EX is a large aircraft, with a fuselage cross-section identical to that of the larger Falcon 900. Despite the voluminous cabin, the initial impression of the aircraft on the ramp at Dassault's Merignac production facility, near Bordeaux, was shaped by its swept wing and long nose. While the passenger cabin is slightly narrower than that of the Bombardier Challenger, it is longer and gives the aircraft a racier appearance. The long nose houses the weather radar. The 19.33m (63.4ft)-span double-swept (29° inboard and 24.8° outboard), supercritical-section wing has highly polished leading-edge devices. Dassault has not followed fashion and installed winglets found on many other business jets.
First impressions
Dassault test pilot Etienne Faurdessus carried out the pre-flight inspection. The walk-around was straightforward. One interesting aspect is the fuselage tail cone. The 2000EX's two large aft equipment bays are nearly empty as there is no need for the centre engine and exhaust duct found on the Falcon 900 from which it was derived. Noise from the tail-mounted auxiliary power unit (APU) was not excessive, especially forward of the wing, where conversation could be conducted at normal voice levels.
Entry to the aircraft is via an electrically actuated door with integral steps. The cabin was "green", as the aircraft was to be ferried to Switzerland for interior installation. Ballast plates just aft of the entry door gave an empty weight and centre of gravity representative of a completed aircraft. A finished cabin is 2.34m wide and provides 1.88m of headroom. The standard layout has eight seats in a double club arrangement. An optional divan can be installed in the rear of the cabin in lieu of two seats. To the rear of the 5.85m-long cabin is a lavatory. Access to the 3.7m2 (39.8ft2) pressurised baggage compartment is via a door on the lavatory's aft bulkhead. The compartment can also be accessed from the ramp via a manual door and steps.
From the left seat, field of view out of the cockpit's seven windows was good, with the outer two-thirds of the left wing visible. The flightdeck on our aircraft, the 14th 2000EX, was identical to that in the standard 2000, featuring a Rockwell Collins Pro Line 4 electronic flight instrument system (EFIS). Starting with the 33rd aircraft, the 2000EX will be delivered with the EASy flightdeck, developed by Dassault and Honeywell. The Pro Line 4 EFIS has four 185 x 185mm (7.25 x 7.25in) liquid-crystal displays, giving both the pilot and co-pilot a primary flight display (PFD) and a multifunction display (MFD). Three Thales 76 x 76mm LCD engine instrument electronic displays occupy the centre of the panel and provide engine, fuel and systems information.
The current displays and their arrangement are on par with those in on the Boeing 757/767 family. The advanced EASy flightdeck will have four 360mm-diagonal displays and a graphical user interface. Designed to increase situational awareness and flight safety, EASy should be a welcome upgrade to an already competent cockpit.
The overhead panel is arranged in a logical manner, clearly displaying systems and their pilot-operated controls. Two control display units mounted on the centre console provide ready access to the dual combined global-positioning/ flight-management systems (FMS).
Pre-start checks and FMS initialisation procedures were similar to other business jets, with inertial navigation system alignment taking less than 6min. Both engines were started individually by bleed air from the APU. Engine start was accomplished by placing the fuel control switch to on, and pressing the start button. The full-authority digital engine control (FADEC) controlled the start, with light-off occurring 10s after starter engagement. Peak inter-turbine temperature was under 600°C (1,110°F) for both engines, well below the 950°C limit. Each engine reached an idle RPM of 23% N1 after 24s on the 13°C day.
Idle power was sufficient to start the aircraft rolling after the parking brake was released. Nosewheel steering is controlled by a side console-mounted knob-shaped tiller. Unlike many other aircraft, the 2000EX's rudder pedals did not provide any inputs to the nosewheel steering.
Parking brake
Hydraulically actuated toe brakes were easy to modulate, while the parking brake provided back-up in the event of the primary system failing.
Faurdessus set the flaps to 20° before turning onto Merignac's runway 23 for take-off. With 3,120kg of fuel, the aircraft had a relatively light gross weight of 13,483kg, or just 72% of the standard maximum take-off weight of 18,734kg. I pushed the throttles to the take-off detent, and released the brakes as the FADECs stabilised the engines at 95% N1. Acceleration was an impressive 0.42g. The nosewheel tiller was released at 80kt (150km/h) indicated airspeed, and a small amount of aileron was put in to counter the 7kt right quartering headwind. At a VR of 112kt about half yoke travel and 14kg of force was required to rotate the aircraft for lift-off.
The aircraft leapt off the runway - 15s from brake release and a ground roll of 500m. More than 20° nose-up pitch was required to maintain the required 125kt (V2+10kt) to 400ft above ground level, when the nose was lowered and the aircraft allowed to accelerate. The yoke-mounted trim switch readily allowed pitch forces to be zeroed out as the aircraft accelerated and gear and flaps were retracted.
Climbing
Once the aircraft was in a clean configuration, the throttles were retarded to the maximum climb detent. While receiving air traffic control vectors to the manoeuvre area, I established the aircraft in a 250kt climb. During the climb, the autopilot was engaged in the flight-level change pitch mode. Passing 10,000ft, the aircraft stabilised at 260kt, while the FADECs maintained the optimum climb power setting. At FL350 (35,000ft), the aircraft transitioned to an M0.75 climb schedule. The autopilot levelled the aircraft at FL450 only 14min after passing 5,000ft and with a fuel burn of 350kg. Dassault estimates that on a standard day a fully loaded 2000EX can climb to FL410 in less than 22min - 2min faster than the shorter-range 2000. The ability to climb directly to FL410 has operational benefits. As well as allowing a rapid climb above weather, it is especially useful over Africa where, according to Dassault flight test engineer Phillippe Narbey, temperatures are often ISA+10°C until above FL400, where they rapidly fall to standard levels.
Once level at FL450, the aircraft was accelerated to M0.8/460kt true airspeed and the throttles pulled out of the maximum climb detent. Stable at M0.8, I pushed the "Mach hold" button located on the forward instrument panel. The word "Mach" appeared under the N1 gauge on the electronic engine instruments to show engagement. This mode allowed the FADEC to control engine N1 within a ±5% range of the set throttle position to maintain a constant Mach number. Actual throttle position did not change and the FADEC effectively held target Mach number.
At a gross weight of 13,027kg the aircraft held 215kt indicated airspeed, with a total fuel flow of 670kg/h. With the throttles in the maximum cruise detent, the aircraft held M0.834/475kt true airspace. Total fuel flow was 800kg/h at 224kt indicated airspeed, about 6kt slower than the maximum operating Mach number (MMO) of 0.85 at this altitude.
The 2000EX's long-range cruise speed is in the M0.74-0.75 range, but slowing to that speed appreciably lengthens the journey while only increasing published range by around 185km.
Engaging the autopilot, it was time to sample the cabin environment. Even though the cabin was green, and the standard entryway acoustic curtain was not installed, ambient noise level was quite low. Returning to the cockpit, the autopilot was turned off and a series of bank to bank turns performed, including some 45°-bank steep turns.
Responsive roll axis
The steep turns were flown at M0.78 and only generated a slight amount of buffet. The 2000EX uses ailerons exclusively for roll control, and the six airbrake panels do not perform a roll spoiler function. Surprisingly, the aircraft's handling qualities in the roll axis were quite crisp and responsive. Initial roll rates were good, in part aided by an effective yaw damper and the tail geometry.
The horizontal stabiliser, mounted midway up the vertical fin, has slight anhedral, resulting in an inverted "V". When the aircraft rolls, it initially generates a small amount of sideslip. A roll to the right, for example, causes the left side of the stabiliser to generate a larger force normal to its surface than the right side. This imbalance is destabilising, and generates a faster initial roll to the right.
Low-speed handling
High-altitude manoeuvres complete, the nose was pushed over for a descent to medium altitude to explore the low-speed handling qualities. During the descent the aircraft accelerated to its MMO of M0.85. Five knots before MMO, the flight director, which had been off, popped up and provided pitch guidance to slow the aircraft. I ignored the advice and stabilised the aircraft at MMO. Aircraft responses to sharp control inputs in each axis were well damped with no residual oscillations. At Faurdessus's direction, the nose waslowered further and the experimental-registered aircraft accelerated past MMO to M0.92. With the exception of an increase in perceived buffet level, the aircraft seemed content flying at speeds well past the placard limit.
After slowing to slightly above M0.85, Faurdessus illustrated why that speed is the MMO. In response to about one-quarter left rudder pedal, surprisingly, the aircraft rolled to the right. This was probably due to the vertical stabiliser and rudder combining to generate a rolling moment to the right larger than the one to the left generated by the swept wing. This served to point out that a wide range of factors must be considered when determining an aircraft's limits. For some, aircraft dynamic pressure may be critical. For the Falcon 2000EX it is a handling qualities issue: throughout an aircraft's flight envelope it should respond in a consistent, predictable manner to control inputs.
Before slowing for a series of approach to stall manoeuvres, a series of "Lazy 8" climbing and diving turns and 45° bank steep turns was performed. During these manoeuvres, the 2000EX's control forces proved to be light in pitch and roll and well harmonised. At FL200, the throttles were retarded to idle, slowing the 12,519kg aircraft in a clean configuration. Passing 138kt, I stopped trimming in pitch while airspeed bled off at 1kt/s. An amber pitch limit indicator appeared on the primary flight display at 134kt and graphically showed the dynamic stalling attitude for the current conditions. At 124kt, the leading-edge slats automatically deployed. No aerodynamic buffet preceded the audible stall warning at 123kt. Control response in all three axes was good, and releasing aft yoke pressure allowed the aircraft to recover to normal flight.
The next approach to stall was in a take-off configuration, gear up and flaps at 20° (leading-edge slats extended). Slowing in idle power from a trim speed of 121kt, the stall warning activated at 101kt. The third and final approach to stall was in the landing configuration, gear down and flaps at 40°. Stall warning occurred at 98kt. As was the case for the previous two stalls, no aerodynamic warnings alerted the pilot to the impending stall. In all cases controllability at the stall was good, and relaxation of aft yoke pressure returned the aircraft to normal flight conditions.
On the approach
Recovery to Merignac was via vectors to an instrument landing system (ILS) approach to runway 23. Using the control display unit, I installed and activated the approach in the FMS. Thirty miles from the field, the FMS automatically tuned the ILS receiver to the correct frequency, easing aircrew workload. Reference speed with 1,185kg of fuel for a flaps 40° landing was 114kt. During the approach I found the V-bar flight director provided excellent guidance and kept the aircraft on course and on glideslope.
Around 59% N1 held the target speed of 120kt required by the 13kt right quartering headwind. At 35ft above ground level I retarded the throttles to idle and began the flare manoeuvre about 20ft above the runway. After levelling out slightly high, I relaxed yoke backpressure and the 2000EX settled softly on the runway. Faurdessus set the flaps to 20° as I advanced the throttles to a take-off setting of 95% N1 for the touch and go manoeuvre.
At 120kt I rotated the aircraft to a 10° pitch attitude. As it lifted off the runway Faurdessus pulled the right throttle to idle to simulate an engine failure. At 130kt (V2+15kt), all available left rudder authority was required to track the runway heading in a wings-level attitude. Banking 5° into the good engine reduced the amount of rudder required to maintain a constant heading as now the aircraft's own weight was used to offset the asymmetric thrust.
One of Dassault's goals for the 2000EX was to have the same minimum control airspeeds (VMCA airborne and VMCG on the ground) as the 2000, despite having more powerful engines. Rather than changing the vertical stabiliser and rudder combination to provide increased control power, Dassault elected to change the thrust line of the engines. Each engine exhaust is angled 2° outward from the fuselage, placing the thrust axis closer to the aircraft's centre of gravity. The 2° offset reduces the forward thrust component by only 0.06%, yet the side force it generates effectively cancels out the additional asymmetric yawing force generated by the more powerful engine.
Landing handling
The simulated engine-out landing was similar to the twin-engined ILS I had flown earlier, except flaps were not set to 40° until 1,000ft above ground level on final approach. Around 65% N1 on the good engine was required to hold a target speed of 120kt. Rudder trim was sufficient to zero out pedal forces both on downwind with 20° flaps and on final approach. Flare and touchdown were uneventful, the rudder allowing the runway centreline to be tracked precisely as power on the good engine was retarded to idle.
Using both engines, I executed another touch and go manoeuvre. The last circuit was a two-engine visual approach and landing to a full stop. Retarding both throttles to idle after touchdown extended the six wing-mounted airbrakes. With the nose wheel on the runway, I was able to engage the thrust reversers as I applied the anti skid-equipped toe brakes for a ground roll of only 300m.
During the 1h 48min flight, the Falcon 2000EX proved a real joy to fly. Control forces and harmony throughout the flight envelope were delightful. Upgraded brakes combine with increased thrust engines to yield balanced field take-off lengths shorter than for the 2000. Larger engines give the 2000EX superior climb performance than its shorter-range stablemate, allowing it to reach FL410 2min sooner after a maximum gross weight take-off.
The spacious passenger cabin is on par with other widebody business jets, while a realistic M0.80 cruise speed will help make short work of a 7,040km flight. These increases in range and climb performance do not come for free, as the 2000EX requires 37% more fuel to fly 25% farther than the 2000. Landing distances for the 2000EX, however, are only a few percent longer than the 2000's. With its Falcon 2000EX, Dassault adds a true non-stop transatlantic capability to its already highly successful Falcon Jet 2000 family.
Source: Flight International
