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Bell 222


bell222

 

In March 1974 Bell decided to commit its own resources to the development of a new twin-turbine, ten-seat helicopter. This helicopter was evolved from studies begun in the late 1960s which had led, in 1973, to the Design D-306, a twin-turboshaft helicopter. The engines were to be either the 500shp Allison 250-C28, the 590shp Lycoming LTS-101 or the 650shp Pratt & Whitney Canada PT7B driving the Bell classic two-blade main rotor. The D-306 could accommodate two pilots and eight passengers (four passengers in executive configuration).


In January 1974, a full-scale mock-up of the D-306 was displayed at the Helicopter Association of America (HAA) convention in order to study the market potential and to gather the would-be customers remarks in order to upgrade the project.


The reactions were so promising that, on 20 April, 1974, Bell announced its decision to go ahead with the Model 222, five prototypes of which were to be built and which were quite similar to the D-306 (the windscreen was improved and the fuselage lengthened by a few inches). The Model 222 was the first completely new Bell design to reach production status since the JetRanger and the Model 222 was described then as 'the first American made light twin-turbine helicopter'. It had a semi-monocoque light alloy fuselage with a hydraulically retractable tricycle undercarriage. The two Avco Lycoming turboshafts drove a two-blade main rotor through a gearbox with two spiral bevel reductions and one planetary reduction.


The maiden flight of the prototype was expected by the end of 1975 but, in fact, the first prototype (c/n 47001, N9988K) got into the air on Friday 13 August, 1976, with Donald Bloom at the controls. Certification by the FAA under FAR Part 29 was received on 16 August, 1979, followed by approval for VFR operation on 20 December of the same year. On 15 May, 1980, the Model 222 received FAA approval for single-pilot IFR operation.


The Bell 222 has a light alloy structure, and a fuselage built around a large cabin which can seat two pilots and five or six passengers in the executive trim. In all configurations, there is a bench seat at the back for three, which fits into the L-shape of the fuel tank behind it. The executive Bell 222 is sold with full IFR capability. One alternative is the offshore configuration for ferrying eight passengers to offshore oil platforms.


The large main rotor with two wide blades is of steel with a honeycomb core. The blades are held to the rotor hub by standard Bell elastomeric bearings. The tail rotor is also metal with two blades. The twin Lycoming LTS-101-650 engines are mounted side-by-side above the fuselage and have integral particle separators. The fuel is contained in three tanks, one in the fuselage and two in the sponsons into which the main landing gear members retract.


During flight tests several improvements were introduced on the prototypes, the most obvious being a completely new tail configuration. With the fourth prototype (c/n 47004, N680L) a new tail layout was adopted: the T tail was replaced by tailplanes and end-plate fins fixed forward of the rear fuselage. The main rotor diameter has been increased by 12 in (30,5 cm) and a slightly more powerful version of the Lycoming turboshaft engine has been adopted, to off-set some weight growth attributable to the new tailplane and larger rotor.


The fifth prototype (c/n 47005, N2228X), representative of the production aircraft, was presented at the Paris Air Show in June 1978. In fourteen months, the five prototypes logged more than 600 flying hours and by December, 1977, the figure of 700 hours was reached. The first for Petroleum Helicopters were delivered in January 1980.
Production was launched with a backlog of orders for some 140 aircraft and Bell had to boost its planned production from 125 machines the first year to 137. On 16 January 1980, Petroleum Helicopters Inc (New Orleans) received the first of its sixteen machines soon followed by Schiavone Construction which received an aircraft in executive configuration. Heliflight Systems (Houston), Aerogulf Sales Co (Dubai), Bemor Agencies (Bermudas), CSE Aviation Ltd (UK) and Astra Helicopters (South Africa) were among the main customers. On 18 January 1981, Bell Helicopters delivered its 25,000th helicopter, a Model 222, to Omniflight Helicopters.


The Model 222 and 222A, first production variants were powered by two 592shp Avco-Lycoming LTS 101-650C-3 engines, their dry weight of only 110kg each providing a maximum power/ weight ratio of 4.58kW/kg at maximum rating.


The Model 222B was the second main production variant with accommodation for seven to nine passengers. The Model 222B incorporates numerous improvements such as a taller main rotor mast, increased diameter narrow-chord blades, larger tail rotor and lengthened tail boom. The powerplant consists of two 684shp Textron Lycoming LTS 101-750C-1 turboshafts. The fuel is contained in five crash resistant tanks located in the fuselage as well as in the sponsons, with a total capacity of 710 litres.


The Model 222B Executive is the luxury variant for five or six people with complete systems and avionics such as IFR, Sperry coupled automatic flight control system and VOR/LOC. Luxury equipment includes automatic temperature control, fluorescent and reading lights and window curtains. A stereo system and refreshment cabinet are optional.


In 1982, the Model 222B became the first transport category helicopter to be certificated by the FAA for single-pilot IFR flight without stability augmentation. Model 222U and 222UT: the Model 222UT (UT for Utility Twin) variant is externally recognisible by its tubular skid undercarriage in place of the usual retractable wheels. It can accommodate up to eight passengers and could have a fuselage mounted flotation system. The powerplant is the same as for the Model 222B but fuel capacity has been increased to 930 litres. This variant received VFR and single-pilot IFR certification during the spring of 1983.


The basic Model 222B feature include:
ROTOR SYSTEM: Two-blade main rotor. Blade section Wortmann 090. Thickness chord ratio 8 per cent. Each blade has a stainless steel spar with bonded glass fibre safety straps to retard crack propagation and offer secondary load path; replaceable stainless steel leading-edge; and afterbody of Nomex honeycomb covered with glass fibre skin. Each blade is attached to the rotor head by two chordwise bolts. Small trim tab on each blade. Completely dry titanium main rotor hub has conical elastomeric bearings. Two-blade tail rotor of stainless steel construction, with preconing, underslung feathering axis and skewed flapping axis. Rotor blades do not fold. A rotor brake is standard.


ROTOR DRIVE: Rotors shaft driven through gearbox with two spiral bevel reductions and one planetary reduction. Transmission rating (two engines) 690kW. Single-engine rating 548kW. Main rotor engine rpm ratio 1:27.4; tail rotor engine rpm ratio 1:5.08.


SPONSONS: Short-span cantilever sponson set low on each side of fuselage, serving as main landing gear housings, fuel tanks and work platforms. Section NACA 0035. Dihedral 3deg 12min. Incidence 5deg. Sweepback at quarter-chord 3deg 30min. All-metal structure of light-alloy sheet and honeycomb. No movable surfaces.


FUSELAGE: Semi-monocoque structure of light alloy, with limited use of light-alloy honeycomb panels. Fail-safe structure in critical areas. One-piece nosecone tilts forward and down for access to avionics and equipment bay.


TAIL UNIT: Cantilever structure of light alloy. Fixed vertical fin in sweptback upper and lower sections. Tailplane, with slotted leading-edge and endplate fins, mounted midway along rear fuselage. Small skid below ventral fin for protection in tail-down landing.


LANDING GEAR: Hydraulically retractable tricycle type. All units retract forward, mainwheels into sponsons. Free-fall extension in emergency. Oleo-pneumatic shock-absorbers, with scissored yoke. Self-centring nosewheel, swivelling through 360degrees. Single wheel and tyre on each unit. Mainwheel tyres size 6.00-6, pressure 5.18 bars. Nosewheel tyre size 5.00-5, pressure 4.14 bars. Hydraulic disc brakes. New-type water-activated emergency pop-out floats optional. Model 222UT has skid-type landing gear and lock-on ground handling wheels, with fuselage-mounted flotation system optional.


POWER PLANT: Two Textron Lycoming LTS 101-750C-1 turboshafts, each rated at 510kW for take-off, mounted in a streamline housing above the cabin and aft of the rotor pylon. Bell focused pylon with nodalisation. Fuel contained in five crash-resistant internal bladders, in fuselage and sponsons, with total capacity of 710 litres in Model 222B. Model 222UT has maximum fuel capacity of 931 litres. Rear seat fuel tank, capacity 246 litres, and parcel shelf fuel tank, capacity 181 litres, optional on both models. Single-point refuelling on starboard side of fuselage. Oil capacity 6.5 litres per engine.


ACCOMMODATION: Pilot and seven passengers in standard 2-3-3 layout, alternatively pilot, co-pilot and six passengers. Two additional passengers can be accommodated in a high-density 2-2-3-3 arrangement. Energy attenuating seats, all with shoulder harness in Model 222B. Crew door at forward end of cabin on each side; cabin door on each side immediately forward of wing. Space for 1.05cu.m of baggage aft of cabin, with external door on starboard side. Ventilation standard; air conditioning and heating optional.


First deliveries of the Model 222UT were in September 1983. Among the main operators are the New York City Police Department, the Port Authority of New York, Michigan State Police, West Virginia State Police and Lloyd Helicopters.


From 1982, the fourth prototype (N680L) served as test bed for the Model 680 four-blade composite bearingless rotor system, designed to improve performance and reduce noise. On 10 November, 1987, this Model 222 flew with a digital control system developed by Bell and Lucas Aerospace which gave the engine the ability to adapt its characteristics in flight.


To 1992, one hundred and fifty-six Model 222Bs and seventy-two 222UTs have been delivered, mainly on the civil market. Only two aircraft are known to have been taken on charge by military customers: one by the Uruguayan Air Force and the other by the Uruguayan Navy.


Production ceased in 1989.


Versions:


222A
Initial production model powered by twin 462kW Lycoming LTS 101 650C-3 turboshaft engines. Replaced from late 1982 by the Model 222B. Total 82 built.

222B
Standard production model from late 1982. More powerful, 510kW Lycoming LTS 101 750C-1 engines; fuselage increased by 0.43m and main rotor diameter 0.69m larger. Strakes added to sponsons. First flight 1 August 1981; FAA certification 30 June 1982. On 29 July 1982, the 222B became the first transport category helicopter to be certified by the FAA for single-pilot IFR flight without stability augmentation. Total of 26 produced between 1982 and 1987.

222B Executive
Fully equipped for both single- and dual-pilot IFR flight. Honeywell coupled automatic flight control system to provide stability augmentation and automatic hold for attitude, altitude, heading and airspeed, plus VOR/LOC course and glide slope hold during approach. Collins Pro Line avionics include dual VHF com, dual VOR nav with glide slope. ADF, marker beacon receiver, transponder, DME and area navigation. Luxury accommodation for five or six passengers, with automatic temperature control, fluorescent and reading lights, window curtains and ceiling speakers. Optional stereo system and refreshment cabinet.

222UT (Utility Twin)
Utility version, incorporating the improvements and power plant detailed for the Model 222B. Retractable tricycle landing gear replaced by tubular skid gear with lock-on ground handling wheels. Fuselage-mounted flotation system optional. Standard seating for a pilot and six or seven passengers. Optional layout for a pilot and eight passengers. First flight 7 September 1982. VFR and single-pilot IFR certification received in Spring 1983; customer deliveries began in September 1983. Total of 80 built up to 1989.


Specifications:


Bell 222
Power Plant: Two Lycoming LTS 101-650C2 turboshafts each with a contingency rating of 675 shp, take-off rating of 615 shp and continuous rating of 590 shp.
TBO: 2400 hr
Max continuous speed, 173 mph (278 km/h) at sea level
Normal cruise @ 3000 ft: 135 kts.
Long-range cruising speed, 150 mph (241 km/h) at sea level
Hovering ceiling (OGE), 8,200 ft (2500 m) in ISA and 4,000 ft (1 220 m) in ISA plus 20 deg C
Hovering ceiling (IGE), 13,000 ft (3962 m) in ISA and 10,000 ft (3050 m) in ISA plus 20 deg C
Single-engine ceiling, 9,000 ft (2743 m) in ISA and 5,100 ft (1555 m) in ISA plus 20 deg C
Range with 20-mm reserve, 400 mls (644 km) at 8,000 ft (2440 m)
Max rate of climb: 1580 fpm.
Service ceiling: 12,800 ft.
FAA empty weight, 4,250 lb (1930 kg)
Standard empty weight: 4860 lb
Useful load, 2,950 lb (1 340 kg)
Take-off gross weight, 7,200 lb (3270 kg)
Fuel flow @ normal cruise: 482 pph.
Endurance @ normal cruise: 2.5 hr.
Max ramp weight: 7850 lb
Max useful load: 2990 lbs.
Max landing weight: 7850 lbs.
Max sling load: 2100 lbs.
Disc loading: 6.3 lbs/sq.ft.
Power loading: 6.4 lbs/hp.
Max usable fuel: 1287 lbs.
Main rotor diameter, 40 ft 0 in (12,19 m)
Overall length, 47 ft 9 in (14,55 m)
Overall height, 11 ft l .5 in (3,39 m)
Fuselage length: 10.98m
Undercarriage -track, 9ft (2,74 m)
Wheelbase, 11 ft 9 12 in (3,59 in)
Span over sponsons, 14 ft (4,27 m).
Accommodation: Up to 10 including pilot.
Baggage capacity, 43 cu ft (1,22 cu.m) in aft cabin and fuselage baggage compartment.

 

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