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Written by AMA Staff
As seen in the August 2015 issue of
Model Aviation.

Horace Hagen’s Cobra

Dieter Schlueter of Germany was the first person to commercially produce and sell a semiscale RC helicopter kit—a scale AH-1G Bell Huey Cobra. Horace Hagen received one of the first 50 kits built and sold by Dieter in April 1971. The kit also had the distinction of being the first RC helicopter kit in the US.

Horace Hagen donated his 1971 Scale AH-1G Bell Huey Cobra to the National Model Aviation Museum
in 2011.

Here is a description, in Horace’s words, of building and learning to fly the Cobra:

“The Cobra kit consisted of a fiberglass fuselage and the machined mechanics. It took me about four weeks to complete the helicopter using the German instructions and plans. The wooden formers had to be cut out of plywood and fitted into the fuselage. The hardest part of the assembly was the physical alignment between the mechanics and the fuselage.

“I had to make my own rotor blades out of wood. I used white mahogany (also known as Ramin or bastard mahogany) for the leading edge and balsa wood for the trailing edge. The instructions recommended a training gear in the form of a tripod. I made this tripod out of 1 /2-inch dowels and added spring-loaded shock absorbers. This was highly recommended by Dieter as a training aid.

“Since I had no spare parts, I proceeded very cautiously during the initial attempts. All of the initial attempts took place during May at our Monmouth Model Airplane Club flying field behind the Bendix plant in Holmdel, New Jersey. I went one step further than just using the tripod landing gear.

“I tied the three ends of the training gear to a brick via two-foot-long strings so the model could not fly away. However, this meant that I had to hover between the three bricks with only about one foot of slack in the strings. This system saved the heli when the throttle link came off the carburetor and the SuperTigre engine went to full throttle. I had to dive under the spinning main rotor and pull the fuel line off to save the helicopter.

“Looking at my flightlog book, I spent about 1.5 hours trying to hover the helicopter between the bricks. When I arrived at a point where I could hover the heli with all three strings slack for a few seconds, I decided to try my hand at hovering it without the tethers. I was quite shocked by how much easier it was to hover.”

The Cobra in flight over the closed runway at a Red Bank NJ airport, May 1972.

You can read more about Horace’s experiences during the early years of RC helicopters in his AMA History Project biography available at


Beautiful Model!!!! Whatever happened to Schlueter GmbH? They made some fantastic scale birds. As a scale-helo buff, it’s great to see this.

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