Falcon 50 Set to Make an Impact in Australia

Avions Marcel Dassault-Breguet decided to enter the top end of the market after a thorough market study in 1975 that showed clients felt that the Falcon20 cabin was an ideal size; however, the aircraft needed more range and better field performance. The first mock-up was designed around a lengthened Falcon 20 fuselage with a scaled-up Falcon 20F wing and three of the now standard corporate jet engines, the Garrett TFE-731-3 turbofan of 3700 lbs thrust.

Why three engines, you might ask. Surely this means more fuel, more weight, increases the chance of a failure or dispatch delay by 50%andincurs a weight penalty in extra plumbing, controls and electrical hardware. Maybe so, but that third engine ensures that in an engine-out situation, you have lost only 33% of your power, not 50%, and ensures excellent balanced field length and engine-out second segment climb performance. In any case a recently conducted survey of operators had one captain make the comment that ‘the50 burned about the same or less fuel than our Falcon20. Additionally, that third engine enables the Falcon to conform to FAR 121-161 allowing long overwater flights or extended flights over hostile terrain without requiring dispensations.

Back to the initial concept; before metal was ever cut, the designatic had changed to Falcon 50B, the difference being that the older technology Falcon 20F wing was dropped in favour of a new 3D-computer designed wing of the ‘supercritical’ variety. This wing certainly met the original design objectives of achieving optimum performance on medium-haul flights with short take-offs and landings, rather than just long-distance stages. The wing area is actually ten per cent greater than the Falcon 20’s and the 40 per cent thicker ratio at the chord allows for 400 US gallons more fuel in the wing. The excellent lift coefficient, of 2. 5, is better than the Boeing 747 (2 . 3), the Gulfstream II (2. 0) and the Learjet (1. 5).

Full-span hydraulically operated and automatically synchronised leading-edge slats and double-slotted trailing-edge flaps are incorporated. The slats will deploy automatically when the angle of attack approaches critical values. These features allow the aircraft to make approaches in the very low 100 kt area.

The S-duct for the centre engine is another area that did not escape the detailed evaluation of the computer. Most tri-jets have a duct curvature of twice the inside diameter, the 50 is based on four times its inside diameter. The result is a ram air recovery rate of 99. 5 per cent as compared to 96. 9 per cent on the Boeing 727. This of course means that there is very little discernible difference in power between the side engines and the centre engine. In fact, with the engines so close to the centre line, losing an engine in cruise has so little effect on performance that Dassault have installed a special warning light to alert the pilot of the condition. Indeed, should an engine fail, the aircraft can maintain an altitude of 28,000 feet at 30,000 lbs. With two engines out the aircraft can maintain 10,000 feet and in the event of a birdstrike, a single-engine climb after take-off is theoretically possible, though it would require about 200 kts, and then only on cool days at light loads.

Many of the systems are very similar to the Falcon 20’s – such as the flight controls. These are hydraulically actuated by redundant dual-body servo-actuators. The control pressure is supplied through artificial feel units. Pitch trim is provided by electric screw-jack actuators, moving the horizontal stabilizer. Roll and yaw trim is handled by electric motors within the primary control mechanism. Push rods connect all control mechanisms, and also act as a back-up control system.

The hydraulic system consists of two independent 300 psi systems. System number one can be powered by the hydraulic pumps on either engine one or two and feeds the three-axis primary controls, slats, flaps, artificial feel units, landing gear, brake anti-skid system and thrust reverser. Hydraulic system two is powered by the pump on engine three, or an electric pump that also serves as a ground hydraulic supply. System two also powers the three-axis primary controls plus airbrakes, nose wheel, steering and parking brake, and also provides backup power to the leading edge slats and brakes.

The dual bus electrical system consists of system A powered by the nine kilowatt DC starter generators of engines one and two, plus a 23 amp hour Nicad battery. System B obtains its power from the nine-kilowatt DC starter generator on engine three, the second 23 amp hour Nicad battery and the optional (if installed) APU. The AC power comes from three 115-volt, 400-cycle static inverters.

Bleed air anti-ice protection is provided for the wing leading edge, including the slats and all three engine intakes and the centre engine ‘S’ duct. As on the Falcon 20 Dassault have not found it necessary to include anti-icing. The windshield is electrically anti-iced.

The particular Falcon 50 demonstrator that came to Australia S/N 85 (destined for Sony Corp. of America) incorporated the new Dreyfuss interior. It is said that when this particular demonstrator rolled out it generated seven orders within three weeks, and sampling the interior for myself I must say that it was very comfortable and functional. Liberal use has been made of lightweight, high-strength and fire-retardant materials such as Klegecel, Kevlar and Nomex. Dreyfuss, through a combination of colour, unbroken lines, lighting and seats that are lower and wider, have created an appearance of spaciousness. More floor-to-ceiling height, and head-to-ceiling height for seated passengers has been achieved by bonding the liners closer to the aircraft skin. Lowering the seats has also placed the occupants at eye level with the windows offering a far better and more comfortable view out of the aircraft. Through careful design, Dreyfuss has indeed gained an extra 20 per cent of usable space out of the same Falcon 50 cabin.

The interior of S/N 85 featured a rear lavatory, six individual chairs in three-facing sets, a three-place couch, and forward-located galley and entertainment consoles. The facing seats could be pushed together and reclined, making a comfortable bed for those long trans-continental flights. The galley faced the entry door and included the latest automatic coffee maker that also provides hot and cold water piped from a tank in the rear of the aircraft. Opposite the galley, just to the rear of the entrance door was the entertainment console featuring a Sony {what else?) video monitor that extends into the centre aisle. It also contained a Betamax video cassette player and stereo.

Dreyfuss have also turned their attention to the flight deck where they installed the Collins EFIS-85 five-tube Electronic Flight Instrument System. These are inch cathode-ray tubes, driven by three separate computers. Provision has been made for the installation of the EFIS-86 six CRTs when they become available. S/N85 was actually used to certify the EFIS system in the Falcon50-type aircraft.

This particular cabin arrangement of rear lavatory, up-front consoles, lower chairs, lighting and styling was well conceived and superbly executed by Dreyfuss and another accomplishment to add to their long line of successes which include executive aircraft interiors dating back to President Eisenhower’s legendary aircraft Columbine, all the interiors of American Airlines, the Falcon 100 and even such items as the Trimline telephone (marketed in Australia as Gondola) and the Polaroid SX-70 camera.

In summary, Dassault-Breguet have certainly found that there is a significant market for an aircraft capable of short take-offs, intercontinental range and also short-range legs. In fact a recent survey showed that most Falcon 50s in service today are being used primarily on short to medium legs with only the occasional trans-Atlantic or Pacific crossing.

At around $US 12 million comprehensively equipped, it will only be a large corporation that purchases a Falcon 50. However, the aircraft is highly suited to the Australian resources environment, a fact endorsed by at least one local purchaser.