Kellett KD-1

History

Kellett Autogiro was founded in 1929 during the "Golden Age of Flight". Their early work included licensing the Cierva rotorcraft. Despite their appearance, gyrocopters are not true helicopters because their main rotor pylons are not powered at normal power. Instead, the "rotation" effect is used to generate vertical lift, while the motor-driven propeller provides the necessary forward pull/thrust.

The concept was developed by Spaniard Juan de la Cierva and flew for the first time in January 1923.

Kellett produced several early Cierva products before turning his attention to a more interior-oriented design. This work resulted in the Kellett "KD-1" with properties similar to the Autogyro model Cierva C.30. The plane features a traditionally aligned fuselage with the engines in the nose and two open-air cockpits just behind. The engine (Jacobs L-4 radial unit, 225 hp) drives a two-bladed propeller. The tail contains the required horizontal and vertical planes, while the landing gear is fixed in flight and rolls for ground motion.

The aircraft's distinguishing physical features are its three-blade, mast-mounted main rotor, mounted above and in front of the crew positions and above the engine compartment.

The prototype appeared as KD-1, only one example was built. After completing the required testing and certification, the KD-1 entered the commercial field as "KD-1A". Three were built to this standard. The "KD-1B" is similar in form and function, but provides an enclosed cockpit.

Established two of this brand.

The US Army's interest in the design was sufficient to warrant a formal evaluation of the product. This resulted in the assignment of the "YG-1" development designation, covering the single KD-1A example.

The successor "YG-1A" received a radio kit, and the US Army's first production model became "YG-1B" and received seven. One was modified with a constant speed propeller for testing purposes and became the "YG-1C" (later XR-2).

Seven other examples in the "XO-60" guise, powered by a 225 hp Jacobs R-755 radial piston engine. The "YO-60" differs in that it uses a 300-horsepower Jacobs R0915-3 radial engine. Six are made to this standard.

"XR-2" was renamed YG-1C, but was also powered by a 300 hp R-915-3 engine. The "XR-3" was a one-off YG-1B model that was converted to the XR-2 standard, but only entered the evaluation stage and was never further developed.

In actual use, the KD-1 proved to be a successful gyrocopter experiment. It was responsible for the first regular delivery of mail by air using rotary-wing aircraft when such a flight took place on July 6, 1939. For the U.S.

Army, it was also previously the service's first operational rotor platform, eventually gaining a more advanced type. There are also some variants of the Kabaya in Japan: the "Ka-Go" is a prototype based on the KD-1A, which is equipped with a 240 hp Argus As 10 engine.

The Ka-2 was powered by a 245 hp Jacobs L-4MA-7 engine.

Specification

Basic

Production

Roles

Dimensions

Weight

Performance

Performance

Armor

Changes