COVER STORY
New Two-Place
Helicopter Being Tested
Robinson Helicopter Co., of Torrance, California, has started flight tests with its new R-22 lightweight two place helicopter, which the company hopes to sell at $18,000-$19,000, putting the aircraft within reach of present light fixed-wing aircraft buyers.
The No. 1 R-22 flight test machine, a finished production prototype, has com­pleted about ten hours of preliminary tests that tested performance and basic han­dling characteristics. Extended flight testing will begin soon, after this machine has logged about twenty hours. At that time, it will be torn down for a complete inspection and will be instrumented for full-scale loads tests as it is reassembled.
The R-22 cockpit is easily entered via large doors on each side.
A simplified cyclic control stick is mounted between the two seats and dual yoke arms extend right and left to positions in front of each seat. The yoke pivots right and left to provide clearance during entry and egress. Dual collective sticks, with conventional throttle twist grips, are located on the left side of each seat.
Each seat has a small baggage com­partment under it.
The cushions lift upward for access to the compartments, each of which has sufficient volume to accommodate a standard-size briefcase, small packages or a pilot's helmet.
The R-22 has excellent forward and downward visibility through the curved
two-pane windshield and the door windows on each side.
Engine and flight instruments are located on a pedestal at the front of the cockpit between the two sets of rudder pedals. All switches are easily reached from either seat.
Red warning lights are located over the main and tail rotor chip detector in­struments and the engine oil pressure and main gear box temperature gauges. Lights will be added for the cylinder head and oil temperature gauges to facilitate the pilot's instrument panel scan.
The interior of the cockpit is carpeted and finished with bulkhead panels lined with acoustic foam.
The forward firewall in the engine
ROTOR RADIUS - 151 IN.
105 IN.
DECEMBER 1975
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Preliminary R-22 Helicopter Specifications
Main rotor dia.......................................................................................................25.17 ft.
Disk area......................................................................................................497.4 sq.ft.
Disk loading @ 1,230 lb. gross weight............................................................2.473 psf.
Rotor solidity............................................................................................................030
Blade twist..........................................................................................................-8 deg.
Flapping angle to stops.....................................................................±12 deg. minimum
Tip speed @ 2,800 engine rpm..........................................................................672 fps.
Tail rotor dia..............................................................................................................42 m-
Powerplant make & model.................................................................Lycoming 0-235-C2C
Rating (takeoff or continuous).....................................................115 hp. @ 2,800 rpm.
Gross weight........................................................................................................1,230 lb.
Empty weight.........................................................................................................720 lb.
Fuel weight (17 gal.) and oil....................................................................................114 lb.
Payload...................................................................................................................396 lb-
VNK.....................................................................................................................115 mph.
Maneuvering load factor....................................................................................+ 3.5 -0.5
Landing load factor...............................................................+ 3.5 (landing gear + rotor)
Maximum rotor tilt........................................................................12 deg. relative to shaft
Performance at Gross Weight:
Cruise airspeed at 75% power and s.l.............................................................100 mph.
Fuel consumption at economy cruise.................................................................15 mpg.
Approximate range (no reserve)..........................................................................250 mi.
Rate of climb at sea level.................................................................. 1.500 ft./min.
Service ceiling.................................................................................................14,000 ft.
Hover ceiling (out of ground effect)...................................................................5,200 ft.
Hover ceiling (in ground effect).........................................................................6,500 ft.
compartment also is lined with acoustic foam to cut cockpit noise.
Several other design features are used to limit noise and vibration in the R-22, Robinson said. The gear units in the main gear box have high spiral angles, high tooth overlap and run in a splash lubrication system that uses a heavy­weight oil. All of these features reduce gearbox noise and vibration. The engine also has a muffler to help cut exhaust noise.
For more information, write Robinson Helicopter Company, Torrance Airport, Torrance, CA 90505.
Interior of the R-22 cockpit is finished to production standards (top) and is sufficiently roomy for two passengers. Note the unusual cyclic control stick design. The two-bladed tail rotor (left inset) has a tip speed of 599 ft./sec. for low noise. The main ro­tor head (inset above) features coning as well as teetering hinges and an underslung hub for improved stability.
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POPULAR ROTORCRAFT