KellettYG-1B AutoGyro

About

The Kellett YG-1B is the U.S. Army Air Corps designation for the Kellett KD-1 autogyro, a 1930s rotary-wing aircraft developed by the Kellett Autogiro Company of Philadelphia using experience the company had gained building Cierva autogyros under license. Juan de la Cierva's autogyro design — the rotor that turns freely under aerodynamic forces, providing lift without the engine-driven complexity of a true helicopter — had reached the U.S. through the Kellett and Pitcairn licensing agreements, and Kellett's KD-1 was a development of the Cierva C.30 layout.

The U.S. Army Air Corps purchased a single KD-1 for evaluation in 1935 and designated it the YG-1, then bought a second example with additional radio equipment as the YG-1A. A batch of seven YG-1Bs followed — making the YG-1B the most numerous variant of the Kellett autogyro in U.S. military service. The design featured two open cockpits in tandem, fixed tailwheel landing gear, and a 225 hp Jacobs L-4 radial engine driving a tractor propeller. The "D" in the KD-1 designation stood for "Direct control," meaning the rotor was responsible for all control of the aircraft — ailerons, fixed wings, and elevators were not necessary, the rotor itself doing all the work via a mechanism that tilted the entire rotor head in the desired direction.

One YG-1B was modified with a constant-speed rotor and re-designated the YG-1C, then later re-engined with the more powerful Wright R-915 and re-designated the XR-2. Kellett's autogyro program was eventually overtaken by the development of the true helicopter, which removed the limitations of the autogyro layout — but the type's place in pre-helicopter rotary-wing aviation history is secure.

The unmistakable autogyro silhouette — main rotor on a pylon above the fuselage, conventional fixed-wing engine and tractor propeller in front, tail group at the rear — is one of the most unusual scale subjects in modern RC modeling.

In the simulator

A unique rotary-wing scale subject that flies like nothing else in the pack. The autogyro flies the way a real autogyro does — lifted by a freely-spinning rotor rather than a fixed wing, capable of slow flight that no fixed-wing aircraft can match, but requiring its own technique. Use it for sport-scale flying with a distinctive visual signature. Pairs well with grass strips and rural fields. A unique entry in any pack.