Dassault Falcon 20 / Mystêre 20 / Fan Jet

Designed jointly by Dassault and Sud Aviation, the Mystere 20 was based on the proven wing of the Dassault Mystere family of fighter aircraft. The original Dassault biz-jet known as the Mystere XX, was designed 1960/61, and the first metal was cut February 1962. The prototype Mystere 20 (Mystere in France, and Falcon for export sales), registered F-WMSH, flew on 4 May 1963 with 3,300 lbs. s.t  / 1497kg Pratt & Whitney JT12A turbojets, but these were later changed to General Electric CF700s, and in this form flew on 10 July 1964.

A cantilever low-wing monoplane with swept wings and tail surfaces, a circular-section fuselage and retractable tricycle landing gear, the prototype had a fuselage built by Dassault and wings and tail unit by Sud-Aviation. However, for production aircraft Dassault builds the wings and Aerospatiale the fuselages and tail units.

The first production Mystere 20 flew on 1 January 1965. Deliveries began in 1965, and Pan American placed the first orders. Several versions were built, differing by more powerful engines.

Built by Avions Marcel Dassault at Bordeaux, the Mystere aircraft is universally known as the Fan Jet Falcon, this title strictly applies only to the aircraft sold by Pan American. In 1963 Pan American ordered 40 Mystere 20 with option on 120 more. The deal was for $128,000,000 at $800,000 per unit. To the manufacturer the type is still the Mystere 20.

Following certification the Business Jets Division of Pan American World Airways (now known as Falcon Jet Corporation) became interested in this aircraft for sale in North America, where they were marketed under the name Fan Jet Falcon. Newark Air Service Inc was named East Coast maintenance centre for the Mystere 20 in 1964.

The Falcon C original production variant had 4,125 lb st (1870 kgp) CF700-2C turbofans (-2D or -213-2 later, by retrofit), and a gross weight of 26,450 lb (12 000 kg). First flown on 1 January 1965, the Falcon C was certificated on 9 June 1965.

The first production series became identified as the Standard Falcon 20. From this was developed a version with increased fuel capacity, available as the Falcon 20C with the same 1871kg thrust General Electric CF700-2C powerplant as the Standard Falcon, or as the Falcon 20D with the more powerful CF700-2D with a thrust rating of 1928kg. The introduction of 2041kg thrust CF700-2D-2 engines resulted in a version designated Falcon 20E, and the addition of high-lift devices to improve take-off and landing performance and a further increase in fuel capacity were identifying features of the Falcon 20F.

The F model was introduced at Pan Am's request in 1970 to meet a need for a short-field capability, featuring full-span drooping leading edges, being heated by engine bleed air and increased fuel capacity. First flown May 1969 and certificated (to FAR Part36) on 20 January 1970. Standard passenger accommodations provide seating for 8 to 10, while a maximum of 12 to 14 is optional.
The static vents of the F are mounted in a small square plate on the fuselage sides below the cockpit side windows.
A succession of development problems has delayed the ATF3 programme and up to February 1981 the company had been unable to complete the 150-hr endurance test required before the FAA would issue a certificate. This in turn imposed serious delays upon delivery of the Coast Guard HU-25As.
As the higher power of the new engines is matched by increased fuel capacity in the Falcon 20G, the better specific consumption and better specific air range (in terms of miles per lb of fuel) produce a significant increase in actual range: the improvement is of the order of 27 per cent at low altitude in typical search missions and over 20 per cent at high altitudes cruising at Mach= 0. 7. The extra fuel, totalling 130 Imp gal (590 lt), is carried in an auxiliary tank in the rear fuselage, immediately behind the aft cabin bulkhead, and brings total fuel capacity to 1,270 Imp gal (5770 lt).
The engines for the HU-25A are identified as ATF3-6-2Cs, variants of the ATF3-6 that are specially adapted for the Coast Guard aeroplanes. The special features of the -2C version are an additional 6,000 rpm drive in the accessory pack to power a second hydraulic pump (required to drive an additional electrical generator) and the use of aluminium instead of magnesium for the accessory pack easing, to improve corrosion-resistance in the overwater environment in which the Guardian will spend much of its time.
Airframe changes to allow the Falcon to meet the Coast Guard mission, apart from the extra fuel tank and the new engine installation, are relatively minor, and comprise the installation of a wide-vision search window each side at the front of the cabin (in place of the standard windows), provision of a hatch in the cabin floor for the dropping of survival kits, fitting a side-looking camera port and providing hardpoints under the wings and fuselage to carry sensor pods. Two wing points are stressed for loads of 1,450 lb (660 kg) each, and two for 1,120 lb (507 kg); there are also four strong points under the fuselage, two stressed for 1,100 lb (500 kg) each and two for 440 lb (200 kg) each. The aircraft gross weight is increased from the 28,660 lb (13 000 kg) of the Falcon 20F to a maximum of 32,000 lb (14 500 kg).
Internally, the Coast Guard's HU-25A is laid out to be operated by a five-man crew, comprising two pilots, an SSO (surveillance system operator) and two observers, seated alongside the enlarged windows. With most of the starboard side of the cabin occupied by radio and avionics equipment, there is space to port for a three-seat couch for additional passengers.
The first Gardian flew in April 1981. Deliveries to the French Navy began in 1983, and were completed in the following year. Generally similar for the French Navy and the Japanese Maritime Safety Agency. Powered by two 5,538 lb thrust Garrett-AiResearch ATF 3-6-2C turbofan engines, these aircraft carry advanced electronics for their maritime surveillance role.
Several military roles have been developed for the Mystère 20 biz-jet, examples of which    are in service as VIP transports and communications aircraft with a number of air forces throughout the world.
Dassault-Breguet first indicated its intention to introduce a version of the Falcon with new turbofans in the 5,000 lb st (2 268 kgp) class during 1975, when the designation Falcon 20G was applied.
The prototype of the Dassault--Breguet Mystere-Falcon 20G (F-WATF) which had been selected by the US Coast Guard to meet its medium-range surveillance aircraft requirement (known as project HX-XX) was flown for the first time in prototype form on 28 November 1977, being a standard production Falcon 20F fitted with Garrett AiResearch ATF3 engines. It was later fitted with the enlarged observation window at the front of the cabin. Powered by 5,440-1b (2468-kg) thrust Garrett ATF 3-6-2C  turbofans, 41 had been ordered for the Coast Guard for a medium-range surveillance role on 5 January 1977, which allocated the designation HU-25A Guardian, the first of 41 entered service in 1982.

In USCG service the HU-25A is used in the search and rescue role, HU-25B is the pollution control version, and the FLIR-equipped HU-25C modified for the drug interdiction role using a Westinghouse APG-66 search radar.

After the US Coast Guard bought 41 Mystêres as Guardians, Dassault-Breguet developed the Mystère 20H Gardian to meet Aéro-navale needs for maritime surveillance in the Pacific. Before commercial deliveries of the Falcon 20H began, Dassault-Breguet was committed to the delivery of five examples ordered in 1977 by the Aeronavale (French Navy) in the maritime surveillance role for service in the Pacific. These aircraft have been given the name Gardian by Dassault-Breguet and differ from the Coast Guard's Guardian in several important respects in addition to the larger fuselage fuel tank. Observation windows and ventral drop hatch are the same in both aircraft, but the Gardian's external stores provision comprises only four wing stations - two outboard stressed for 1,430 lb (650 kg) each and two inboard for 1,650 lb (750 kg) each.
Like the HU-25A, the Gardian is powered by ATF3-6-2C engines to take advantage of the additional constant speed drive for a hydraulic motor to drive a 20 kVA alternator, but there is a further increase in gross weight, to a permissible maximum of 33,510 lb (15 200kg).
The basic layout of the Gardian fuselage differs in detail from that of the HU-25A, and provides for an operational crew of six plus a four-seat couch. In addition to two pilots and two visual observers, the crew includes a navigator and a radar operator, seated side-by-side at the rear of the cabin and facing the main equipment consoles on the right-hand side. Without major difficulty, an additional four-seat couch can be fitted, to bring total occupancy to 14; alternatively, two stretchers can be carried in place of the two couches, or four VIP seats and removable tables can be fitted in the central cabin area, in all cases without removing the rear equipment consoles or the forward observation seats.
A number of airframes have been used by Dassault-Breguet, FJC and Garrett AiResearch in the development of the Falcon 20G, 20H and Guardian variants. On 28 November 1977, Falcon 20F No 362 was flown for the first time, at Bordeaux, in the guise of the Falcon 20G prototype, fitted with a pair of ATF3 engines (the first time these engines had flown). To increase the engine development flying, a Falcon 20C (No 137) was acquired by Garrett AiResearch in 1977 and first flew on 17 June 1978 after being fitted with an ATF3 on the starboard side only, retaining the standard CF700 to port.
The Falcon 20G designation is applicable only to the HU-25A Guardian for the US Coast Guard. It has been superseded commercially by the Falcon 20H, announced in mid-1979. Using the same basic engine installation as the Falcon 20G, the 20H differs in having a number of features that the company has meanwhile developed in the course of design and production of the three-engined Falcon 50. Most significant of these features is the rear fuselage tank, which in the Falcon 20H has a capacity of 189 Imp gal (860 lt) - the same as that used in the Falcon 50 and substantially larger than the new tank introduced in the Falcon 20G. Also based on the Falcon 50 experience, the systems in the Falcon 20H have been extensively modified for improved performance, greater reliability, easier maintenance and reduced weight. Complete spares interchangeability between Falcon 50 and Falcon 20H is achieved by introducing, in the latter, a new duplicated hydraulic system with separate pumps; two segregated electrical systems of increased power; a new ABG/SEMCA air conditioning system; an automatic stability system, Mach trim, yaw damper and flap asymmetry limiter; and, as options, a Solar T62 APU and the Collins APS-80 autopilot already specified for the HU-25A Guardian. Gross weight of the Falcon 20H is increased, like that of the 20G, to 32,000 lb (14 500 kg), and the aft limit CG position is moved back from 28 to 35 per cent, thanks to the introduction of a system that automatically extends the inboard wing leading-edge slats at high angles of incidence. The cabin of the Falcon 20H is unchanged in size from that of the earlier aircraft, and various layouts for 8 to 14 passengers were available. First flown 30 April 1980.
The first of five Dassault-Breguet Gardians for Aeronavale made its maiden flight on 15 April at Bordeaux-Merignae, and a second flight was made the same day to ferry the aircraft to Istres. The Gardian is a maritime patrol version of the Mystere-Falcon 20H, carrying Thomson-CSF Varan radar and a new Crouzet navigation system. It has an air-openable forward door to allow large items, such as rescue rafts, to be dropped, and four wing hardpoints for various loads such as sensor packs, target-towing equipment, weapons and ECM pods.
The first Falcon 20 to undergo conversion into a Falcon Cargo was scheduled to begin certification flight trials on March 1, 1972. A cargo-loading door has been substituted for the normal entrance in the port forward fuselage during modification by Little Rock Air-motive to a Pan Am Business Jet requirement.
The Canadian Armed Forces operated the Falcon 20 as the CC-117 until 1988.

The Mystere-Falcon 20 found employment for both civil and military use with orders approaching 500.

The Falcon 200 replaced the Falcon 20F on the production line in 1983, after 473 Falcon 20s had been delivered. Originally designated Falcon 20H the prototype 200, fitted with less powerful 2360kg thrust ATF 3-6A-4C engines, bigger fuel tanks in the rear fuselage, some systems' changes and redesigned wing root fairings, flew for the first time on 30 April 1980. Announced at the 1981 Paris Air Salon the Falcon 200 was certificated by the DGAC on 21 June 1981 and deliveries began in 1982. By 1989 35 had been delivered to 11 countries. The maritime patrol and enforcement version of the Falcon 200 is marketed as the Gardian 2, and has a Thomson-CSF Varan search radar, two Exocet sea-skimming air to surface missiles mounted on underwing pylons, electronic surveillance and countermeasures equipment and target-towing capability. Five were in service with the French navy.
The Falcon 200 has a max cruising speed of 531 mph and an economic cruise of 475 mph over 2590 miles.
The last Falcon 200 was produced in 1988.

The three RAAF aircraft were Mystere 20C models, with the capability to deploy a drag chute on landing. The 400 series constructor numbers indicate built to FAA certification.

Mystere 20 prototype
Engines: 2 x Pratt & Whitney JT12A-8 turbojets, 3,300 lbs. s.t  / 1497kg - laterCF700 turbofans

Standard Falcon 20
Engines: 2 x General Electric CF700-2C, 1871kg / 4,315-lb. s.t. thrust
Gross wt. 28,660 lb
Empty wt. 15,970 lb
Fuel capacity 1,385 USG
Seats 8-14
Top speed: 465 mph.
Cruise speed: 405 mph
Stall: 95 mph.
Range 2,200 miles
Ceiling: 2,000 ft
Takeoff distance (35 ft): 3,790 ft
Landing distance (50ft): 1,930 ft

Falcon 20C
Engines: 2 x General Electric CF700-2C turbofans (-2D or -213-2 later, by retrofit), 1871kg / 4,125 lb st thrust
Wing span: 16.3m / 53 ft 6 in
Length: 17.15m / 56 ft 3 in
Height: 5.32m / 17 ft 5 in
Empty weight: 7000 kg / 15,430 lb
Gross weight: 27,115 lb / 12,300 kg
Max speed below 23,500 ft: 425 mph / 684 kph
Max speed above 23,500 ft: M0.88
Ceiling; 42,000 ft / 12,800 m
Stall: 99 mph / 160 kph
Max range at 20,000 ft: 870 nm / 1610 km
Passenger capacity: 8

Falcon 20D
Engines: 2 x CF700-2B, 4,250 lb st (1930 kgp).
Total cabin volume: 700 cu ft (20 cu.m).
Forward baggage compartment: 35cu ft (1cu.m).
Aft baggage compartment: 15 cu ft (0.4cu.m).
Total fuel cap: 1,100 imp gal (1,315 US gal, 5,000 lit).
Unusable fuel: 32 imp gal (38 US gal, 145 lit).
Gross weight: 27,337 lb (12 400 kg).

Falcon 20D
Engines: 2 x CF700-2D, 1928kg

Falcon 20E
Engines: 2 x General Electric CF700-2D-2, 4,315 lb st (1960 kgp)
Total cabin volume: 700 cu ft (20 cu.m).
Forward baggage compartment: 35cu ft (1 cu.m).
Aft baggage compartment: 15 cu ft (0.4 cu.m).
Total fuel cap: 1,148 imp.gal (1,372 USgal, 5,220 lit).
Unusable fuel: 32 imp gal (38 US gal, 145 lit).
Gross weight: 28,660 lb (13 000 kg).

Falcon 20F
Engines: 2 x GE CF700-2D-2, 4,315 lb, 19.2kN thrust
Overall wingspan: 53ft 6in (16.3m).
Overall length: 56ft 3in (17.15m).
Overall height: 17ft 5in (5.32m).
Wheelbase: 18ft 11in (5.77m).
Wheel track: 11 ft 6 in (3.5 m).
Wing area: 440sq ft, 41sq.m.
Wing aspect ratio: 6.4.
Maximum ramp weight: 28,660 lbs.
Maximum takeoff weight: 28,660 lb / 13,000kg
Standard empty weight: 17,060 lbs.
Maximum useful load: 11,600 lbs.
Zero-fuel weight: 19,600 lb / 8,900kg
Maximum landing weight: 27,320 lb / 12,380kg
Wing loading: 65.1 lbs/sq.ft.
Power loading: 3.2 lbs/lb.
Total fuel cap: 1,148 imp.gal (1,372 USgal, 5,220 lit) / 9,240 lb, 4,180kg
Unusable fuel: 32 imp gal (38 US gal, 145 lit).
Best rate of climb: 3650 fpm
Certificated ceiling: 42,000 ft.
Max pressurisation differential: 8.3 psi.
8000 ft cabin alt @: 42,000 ft.
Maximum single-engine rate of climb: 900 fpm @ 203 kts.
Single-engine climb gradient: 266 ft/nm.
Single-engine ceiling: 15,000 ft.
Maximum speed: 453 kts.
Normal cruise @ 37,000ft: 432 kts.
Fuel flow @ normal cruise: 1930 pph.
Stalling speed clean: 119 kts.
Stalling speed gear/flaps down: 93 kts.
Turbulent-air penetration speed: 250 kts.
VMO SL: 350kt, 650krn/hr
VMO 23,000ft: 390kt, 720krn/hr
MMO Mach 0.88
VFE 190kt, 355km/hr
VLO 190kt, 355km/hr
VLE 220kt, 410km/hr
VMCA 98kt, 182km/hr
Balanced field length: 5,300ft at max weight ISA SL.
Passenger accommodation: 8-10 / 12-14 option
Total cabin volume: 700 cu ft (20 cu.m)
Forward baggage compartment: 35cu ft (1 cu.m)
Aft baggage compartment: 15 cu ft (0.4 cu.m).

Falcon 20G / HU-25A Guardian
Engines: 2 x Garrett ATF 3-6-2C turbofans, 5,440-1b (2468-kg) thrust
Length: 56 ft 3 in / 17.14 m
Height: 17 ft 5 in / 5.2 m
Wingspan: 53 ft 6in / 16.3 m
Wing area: 449.935 sq.ft / 41.8 sq.m
Aspect ratio: 7.02: 1
Empty weight: 19,000 lb (8 620 kg)
Equipped empty, 5 crew: 20,890 lb (9 475 kg)
Max take-off weight: 32,000 lb (14 515 kg)
Max zero fuel: 22,520 lb (10215 kg)
Max landing, 27,580 lb (12 510 kg)
Wing load: 67.86 lb/sq.ft / 331.0 kg/sq.m
Total fuel capacity: 1,270 Imp gal (5770 lt / 10,220 lb / 4 636 kg
Max. speed: 469 kts / 869 km/h
Max cruising speed: M = 0. 80, 531 mph (855 km/h) at 40,000 ft (12200 m)
Economical cruising speed, M=0.72
Minimum low-altitude manoeuvring speed, 173 mph (278 km/h)
Take-off run, max weight, ISA at SL: 4,050 ft (1235 m)
Max range with crew of five, 5 per cent fuel res plus 30 min: 2,590 mls (4170 km)
Undercarriage track: 12 ft 1.25 in (3,69m)
Wheelbase: 18 ft 10 in (5,74 m)
Crew: 5, two pilots, an SSO (surveillance system operator) and two observers.
Passengers: 3
Hardpoints: 2 x wing points 1,450 lb (660 kg) each, 2 x wing points 1,120 lb (507 kg); 2 x fuselage 1,100 lb (500 kg) each, 2 x fuselage 440 lb (200 kg) each.

Falcon 20G / HU-25B
Engines: 2 x Garrett ATF 3-6-2C turbofans, 5,440-1b (2468-kg) thrust
Length: 56.234 ft / 17.14 m
Height: 17.06 ft / 5.2 m
Wingspan: 53.478 ft / 16.3 m
Wing area: 449.935 sq.ft / 41.8 sq.m

Falcon 20G / HU-25C
Engines: 2 x Garrett ATF 3-6-2C turbofans, 5,440-1b (2468-kg) thrust
Length: 56.234 ft / 17.14 m
Height: 17.06 ft / 5.2 m
Wingspan: 53.478 ft / 16.3 m
Wing area: 449.935 sq.ft / 41.8 sq.m

Falcon 20H / Mystère 20H Gardian
Engines: 2 x Garrett ATF 3-6-2C turbofans, 5,440-1b (2468-kg) thrust
Span: 16.3 m.
Length: 17.2 m.
Wing area: 41 sq.m.
Empty wt: 8700 kg
Gross weight: 33,510 lb (15 200kg).
Hardpoints: four wing - two outboard 1,430 lb (650 kg) each and two inboard 1,650 lb (750 kg) each.
Warload: 1640 kg
Max speed: 860 kph.
Ceiling: 13,700 m.
Fuel internal: 6000 lt.
Range: 4490 km.
Air refuel: No
Operational crew: 6
Passengers: 4
Total seating: 14

Falcon 20H
Engines: 2 x Garrett ATF 3-6-2C turbofans, 5,440-1b (2468-kg) thrust
Wing span: 53 ft 6 in (16.3 m)
Gross weight: 32,000 lb (14 500 kg)
Max cruise: 531 mph (855 km/h).
Hardpoints: 4

Falcon 200
Engines: 2 x Garrett ATF 3-6A-4C turbofans, 2360kg / 5400 lb thrust
Empty weight: 17970 lb
Gross weight: 30650 lb
Useful load: 12680 lb
Max cruising speed: 531 mph
Economic cruise: 475 mph
Economic cruise range: 2590 miles.
Seats: 8/10