Although one of the most successful civilian helicopters since the Bell JetRanger, the R.22B was limited to only two people and in the summer of 1986 Frank Robinson began designing a larger four-seater version as the R44.
Designated R44, this new aircraft closely resembled its smaller sibling and retained the two-blade main rotor layout. Designed to the requirements of FAR Pt 27, features include electronic throttle governor to reduce pilot workload by controlling rotor and engine rpm during normal operations, rotor brake, automatic clutch engagement to simplify and reduce start-up procedure and reduce chance of overspeed, and T-bar pistol grip cyclic control.
The R44 is powered by the Lycoming 0-540-F1B5 engine, which normally produces 260 hp at 2,800 rpm. In the R44, the rpm is reduced to 2,692, and the pilot is limited to using 225 hp for five minutes and 205 hp for maximum continuous power. The five-minute power setting (225 hp) is only 86.5% power, while 205 hp is just 78.8%. 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 TB0s to 2,200 hours. This is the first time a helicopter powered by a reciprocating engine has been given a longer TBO than fixed-wing aircraft powered by the same engine.
The R44 Astro Lycoming O-540 FIB5 gives a cruise speed of 210km and a range of 640km plus.
Flying controls are conventional, with Robinson central cyclic stick; rpm governor; rotor brake standard. The left-hand collective control lever and pedals can be removed if required. Four persons are seated 2 + 2. Baggage stowage beneath each seat. Dual controls. Cabin heated and ventilated. Tinted windscreen and door windows.
The prototype (N44RH) first flew on 31 March 1990 and two aircraft were engaged on the flight test programme. The first two R44s built accumulated more than 200 flying hours between 1990 and 1992. A third aircraft flew in March 1992, and the type was certificated on 10 December 1992.
A new production site at Santa Maria, California, has been prepared for the R44, though the first 25 aircraft were built at Torrance alongside the R22. This first batch of helicopters was only being released to customers in the south-western USA, in case they need to be recalled for modifications.
Introduced onto the market in 1993, the R-44 Astro was as successful as the smaller R-22 Beta with both operators and private owners who are moving into more cost effective machinery which combines turbine performance with piston engine economy. On 22 March 1992 36 deposits of $15,000 was taken on the first day of R44 sales. During 1994 Robinson sold over 195 helicopters — 89 R-22s and 106 R-44s.
Export deliveries commenced in 1993. By mid-1993 orders were approaching 150. Fuel consumption is less than 68 litres per hour, and the patented Robinson tri-hinge rotor is fitted with a rotor brake. Flyaway cost of a fully equipped R44 was listed at $235,000. 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; tow cart adapter, rotor blade tie-downs; and windscreen cover. Optional equipment includes three-cylinder engine priming system; RHC oil filter; observation bubble windows; cabin heater/ defogger; metallic base or trim exterior colours; and leather seats.
The first R44 to reach 2,000 hours was the seventh production machine, which was returned for overhaul in mid-1996. By January 1997, 308 R44s were operating in 38 different countries.
In August 1997 an R44 became first piston helicopter flown around the world.
A total of 1,125 were delivered by 1 Septemeber 2001. Deliveries had totalled 150 in 1999, 264 in 2000, and 194 in 2001. Total of 57 delivered in first three months of 2003. 1,000th delivery took place in February 2001.
In June 2002 an R44 Raven (G-NUDE) became the first piston-engined helicopter to land at the North Pole.
Japanese certification was achieved on 18 November 2002.
COSTS: Raven I US$307,000, Raven II US$343,280; Clipper I with utility floats US$323,000, Clipper II with utility floats US$356,000. Clipper II with pop-out floats US$363,000, R44 Police Helicopter US$509,000, R44 Newscopter US$549,000 (all 2003). Direct operating cost US$43.30 per hour; total (500 hours annually) US$131.87 per hour (both 2003).
Landing gear varys with fixed skids; or, on R44 Clipper I, twin utility floats; or, on R44 Clipper II, twin utility floats, or pop-out helium floats, which inflate in 2 seconds.
The Raven features as standard a hydraulic flight control system, maintenance free ‘elastomeric’ tail rotor hinge bearings, RPM governor, rotor brake and auxiliary fuel. The 260hp O-540 is derated to 205hp (maximum continuous) and 225 hp (5 minute take-off rating). The Raven II has a fuel injected IO-540 de-rated to 245 hp for five minutes and 205 hp maximum continuous. This gives better altitude performance and a 100 lb increase in payload.
R44 Raven I: Basic version, introduced in April 2000 to replace Astro; features 194kW Textron Lycoming O-540 engine derated to 168kW at T-O, 153kW continuous; hydraulic control system standard; plus elastomeric tail rotor bearings and adjustable pedals for pilot.
R44 Raven II: Upgraded version introduced in June 2002. FAA certification 10 October 2002; first deliveries November 2002. Features a Textron Lycoming IO-540 engine, 28V 70A electrical system, increased lifting area on main rotor blades, and aerodynamic tip caps on main and tail rotor blades. Total of 124 ordered and 40 delivered by February 2003, including two ENG variants. As described.
R44 Clipper I and Clipper II: Float-equipped versions, initially certified (as R44 Clipper) 17 July 1996. Both versions available with twin utility floats; pop-out floats available only on R44 Clipper II. Total of 141 Clippers sold by 1 June 2001. The Clipper was available 2003 for $281,000.
R44 Police Helicopter: Specially modified Raven II for law enforcement, with Inframetrics 445G Mk II IR sensor, TV camera and x7 zoom lens mounted in gyrostabilised nose turret; LCD video monitor; Spectrolab SX-5E 15 to 20 million candlepower searchlight; FM radio package; bubble door windows; Bendix/King KFM 985 dual-band transceiver, KY 196A VHF, II Morrow Apollo SL-60 standby comms, KT 76C transponder, 28V electrical system and extended landing gear struts. Empty weight, equipped, approx 715kg. Certified July 1997; first customer El Monte Police Agency of Los Angeles. Recent customers include the Estonian Air Force, which ordered two in February 2002 for delivery commencing May 2002, and China's Zheng Zhou Public Security Bureau, which took delivery of one in June 2002 following its appearance at the China Expo 2002 exhibition.
R44 Newscopter: Digital electronic news gathering (ENG) version of Raven II intended for media companies and fitted with Ikegami HL-59WNA digital camera with x21 lens and 360° continuous rotation with five-axis gyro stabilisation; and microwave transmitter; four video monitors, two micro cameras, KY 196A VHF, KT 76C transponder (Mode C), GPS, two FM radios and bubble window in port door. Deliveries began January 1998; 29 sold by 1 June 2002. First digital ENG Raven II delivered on 9 February 2003 to Sky Helicopters of Garland, Texas, and was the 30th ENG Newscopter delivered.
R44 IFR: Equipped for IFR helicopter training IFR package adds US$27,200 to standard cost. 18 Sold by 1 June 2001.