12/31/2009. Remarks by Walter van Tilborg: "The single-seat C-122 Rainbow helicopter was a design of Russell Chadwick, and was intended to be available in kit form for amateur construction. Powered by a 40 hp Rotax 503 two-stroke piston engine, the prototype started tethered tests late 1985 and was mainly intended as a proof of concept/technology demonstrator.

In 1986 Chadwick formed Chadwick Helicopters International, Inc. at Sherwood, Oregon for development, marketing and production of the type in ready-to-fly form. These were to have a longer tail boom, new rotor blades and a tail rotor guard ring, but reportedly only two C-122S machines were built and further development was halted."

Rotor diameter: 18 ft 6 in (5.64 m)
Rotor disk: 268.8 sq.ft (24.97 sq.m)
Length (rotors turning): 22 ft 6 in (6.86 m)
Height: 7 ft 2.25 in (2.19 m)
Weight empty: 253 lb (115 kg)
Weight loaded: 500 lb (227 kg)
Max speed: 94 mph (151 kmh)
Cruise speed: 74 mph (119 kmh)
Climb: 945 ft (288 m)/min
Service ceiling: 13,480 ft (4,110 m)
Range: 120 mls (193 km)