From the time that helicopters became practical aircraft their unit costs have always been high in comparison with those of fixed-wing aircraft of similar capacity. In the United States Franklin D. Robinson formed the Robinson Helicopter Company, based at Torrance in California, to design and market a lightweight civil helicopter which would be competitive in price with two-seat fixed-wing aircraft then on the market.

Robinson produced the small two-seat R-22, powered by a Lycoming piston engine and the two-blade rotor system was designed around a patented three-hinge coupling that does away with lag hinges, dampers and hydraulics. The O-320 normally runs at 2,700 rpm to produce 160 hp. Robinson reduced the rpm to 2,652 and limited the pilot to only 131 hp for five minutes and 124 hp for maximum continuous power. An elastic teeter hinge stop was later included to prevent the rotors from striking the tail boom while winding up or running down in gusting winds (Beta model). To reduce operating costs the R-22 is built from non-exotic materials, relying on standard aerospace metals with an emphasis on durability and maintainability. Other than routine maintenance every 100 hours, the helicopter only requires a factory overhaul every 2000hrs of flight.

Design began in 1973 and the first R-22 flew on 28 August 1975, followed by a second in early 1977, and these two aircraft were used to gain FAA and CAA certification on 16 March 1979 and June 1981 respectively. The R22 was the first helicop¬ter to be certificated under the new and more stringent FAR Part 27. Deliveries began in October 1979. The R-22 sold quickly and in 1983 a modified R-22A was certified to allow the helicopter to undertake IFR training and operate with US Police Forces who had shown an interest. Over 500 of these models sold world-wide and in August 1985 the R-22 Beta model was announced.

A simple, pod-and-boom light helicopter; horizontal stabiliser, starboard side only; vertical stabiliser above and below boom; offset to starboard; tall rotor mast. Horizontally mounted piston engine drives transmission through multiple V belts and sprag-type overrunning clutch; main and tail gearboxes use spiral bevel gears; maintenance-free flexible couplings of proprietary manufacture used in both main and tail rotor drives. Two-blade semi-articulated main rotor, with tri-hinged underslung rotor head to reduce blade flexing, rotor vibration and control force feedback, and an elastic teeter hinge stop to prevent blade-boom contact when starting or stopping rotor in high winds; blade section NACA 63-015 (modified); two-blade tail rotor on port side; rotor brake standard.

Flying controls are manual. Removable dual controls standard. All-metal bonded blades with stainless steel spar and leading-edge, light alloy skin and light alloy honeycomb filling; frame section of steel tube with light alloy skinning; full monocoque light alloy tailboom. Welded steel tube and light alloy skid landing gear, with energy-absorbing crosstubes.

The basic model, which became known as the R22 Alpha, was replaced from the 501st aircraft onwards, in 1985, by the upengined R22 Beta. Improvements to the R-22 Beta model include uprated 160hp Lycoming O-320-B2C engine, high-capacity oil cooler, improved heater, demister, silencer and rotor brake. This two-seater can cruise at 178km/h and with a twenty US gallon tank of fuel travel for 385km. The Beta was certified on 5 August 1985. The more powerful Textron Lycoming O-360 engine provides better high-level hover performance and allows take-off power to be sustained up to 2,285m. Previously optional, tinted windscreen and door windows were fitted as standard. Production began at c/n 2571.

Despite the company’s small size, Robinson achieved a production rate of about 30 R22s per month, with 402 produced in 1991 alone. There have also been military customers, such as Turkey, who ordered 10 for basic pilot training. Over 2300 R22s of all versions had been delivered by early 1993. Total production of the R22 had exceeded 2,500 aircraft by 1995.

Japanese certification was achieved on 18 November 2002. By September 2003, Robinson had produced 5,000 helicopters, including 390 in 2000, 328 in 2001 and 255 in 2002. Production rate 11 helicopters per week in 2003. Factory floor area 24,150 sq.m. Workforce totals 820. Company is ISO 9001 certified.

The R22 Beta II cost US$170,000 for the basic version in 2003. The engine is mounted in the lower rear section of the main fuselage, with cooling fan. Over the years, Lycoming has been so impressed with the reliability and condition of both the R22 and R44 engines that they actually increased the TBOs to 2,200 hours. Light alloy main fuel tank in upper rear section of the fuselage on port side. Transmission overhaul interval 2,200 hours or 12 years.

Two seats side by side in enclosed cabin, with inertia reel shoulder harness. Curved two-panel, tinted windscreen. Removable door, with tinted window, on each side. Baggage space beneath each seat. Cabin heated and ventilated. Electrical system, powered by 12V DC alternator, includes navigation, panel and map lights, dual landing lights, anti-collision light and battery.

Standard equipment includes rotor brake; tinted windscreen and windows; belly hardpoint; dual landing lights; navigation, panel and map lights; anti-collision light; ground handling wheels; rotor blade tiedowns; and windscreen cover.

Optional equipment includes three-cylinder engine priming system; RHC oil filter; cabin heater/defogger; metallic base or trim exterior colours; and leather seats.

The R22 was purchased by only a couple of military customers, the Turkish Army, in 1992 and Argentina, mainly for use by the Buenos Aires Police.

Variants:

R22 Mariner: fitted with floats and wheels, first delivered for offshore work in Mexico and Venezuela

R22 Police: version with special communications fit and optional port-side controls. Uprated electrical generator for searchlight, loudspeaker, siren and ATC transponder

R22 IFR: training version with improved flight instruments and radio for Instrument Flying Rules operations

External load R22: additional cargo hook certified to carry 181kg underslung load. When fitted aircraft has a VNE (never exceed speed) limit of 139km/h. Conversions undertaken by Classic Helicopter Corp. of Boeing Field, Seattle, Wa.

R22 Agricultural: equipped with low-profile belly hopper and spray-bar system

Gallery

Specifications:

R-22
Engine: Lycoming O 320-A2B, derated to 124 hp
TBO: 2,000 hrs
Rotor: Two blade, teetering, 25 ft. dia
Length: 21 ft. 10 in
Height: 8 ft. 9 in
Max ramp weight: 1,300 lbs
Max takeoff weight: 1,300 lbs / 621kg
Standard empty weight: 790 lbs
Max useful load: 510 lbs
Payload max fuel: 389 lb
Disc loading: 2.6 lb/sq.ft
Power loading: 10.5 lb/hp
Max usable fuel: 20 USG/120 lbs
Max rate of climb, sea level: 1200 fpm
Max rate of climb, 5,000 feet: 1060 fpm
Max operating altitude: 14,000 ft
Max speed: 101 kts
Cruise, 65 % power at 8,000 ft: 94 kts
Fuel flow at 65 % power: 8 USG/hr
Endurance at 65% power, no res: 2.5 hrs
Max cruise: 96 kt
Max range cruise: 87 kt
Range max fuel/ cruise: 108 nm/1.1 hr
Range max fuel / range: 118 nm/ 1.4 hr
Service ceiling: 14,000 ft
Hover in ground effect: 6500 ft
Hover out of ground effect: 4500 ft
Seats: 2
199 built

R22HP
Engine: Lycoming O-320-B2C, 160 hp de-rated to 124 hp
TBO: 2000 hrs
Main rotor: 25.2 ft
Seats: 2
Length: 28.7 ft
Height: 8.8 ft
Max ramp weight: 1300 lbs
Max takeoff weight: 1300 lbs / 621kg
Standard empty weight: 800 lbs
Max useful load: 500 lbs
Zero fuel weight: 1184 lbs
Max landing weight: 1300 lbs
Disc loading: 2.6 lbs/sq.ft
Power loading: 10.5 lbs/hp
Max usable fuel: 120 lbs
Max rate of climb: 1200 fpm
Service ceiling: 14,000 ft
Hover in ground effect: 8,300 ft
Hover out of ground effect: 6,400 ft
Max speed: 102 kts
Normal cruise 75% @ 3000 ft: 94 kts
Fuel flow @ normal cruise: 48 pph
Endurance @ normal cruise: 2.3 hr
151 built

R-22 Alpha
Engine: 1 x Textron Lycoming O-320-B2C, 160hp derated to 124 hp
Instant pwr: 95 kW
Rotor dia: 7.7 m
MTOW: 1370 lb, 621 kg
Empty wt: 824 lb, 380 kg
Useful load: 240 kg
Fuel cap: (19.2 gallons) 115 lb, 75 lt
Pilot, passenger and Baggage 431 lb
Vne: 102 kts
Cruise Airspeed 75%: 96 kt
Maximum Range (No Reserve) 208 nautical miles
ROC @ 53 kt: 1000 fpm
HIGE: 6970 ft
HOGE: 5200 ft
Service ceiling: 14,000 ft
Crew: 1
Seats: 2
151 built

R22 Beta
Engine: 1 x Textron Lycoming O-320-B2C, 119kW, 131 hp for five minutes and 124 hp continuous
Main rotor diameter: 7.67m
Length: 6.3m
Height: 2.67m
Max take-off weight: 621kg
Empty weight: 379kg
Max speed: 180km/h
Ceiling: 4265m
Range with max payload: 592km
Crew: 1
Passengers: 1

R22 Beta II
Engine: Lycoming O-360, 131 hp
MTOW: 1370 lb
Empty wt: 855 lb
Usable fuel capacity: 72.5 lt
Optional auxiliary fuel capacity: 39.75 lt
HIGE: 9400 ft
Max op alt: 14,000 ft