What was the first unpowered and untethered RC sailplane?
Am curious what the thing looked like, and what radio gear people had to play with at the time? Probably rudder only controlled?

Lanzo had a RC glider in the air in late 30's

I remember an article in RCM on a vintage RC glider. Or was it MA? A huge Minimoa looking contraption with a plywood veneer. Kind of attractive. Apparently they entered it in a full scale sailplane contest.

Does that article ring a bell for anyone?

Tom

Lanzo designed and built most of his early radio gear. From some old articles I've read, he even had to design and build his own escapement actuators. One article on constructiong one of his radios had things like "Wind coil L-1 from #32 enameled magnet wire onto a 5/8" diameter wood core. Keep each winding approximately the width of the wire apart." I don't know if it would even be possible to get some of the tubes he used. At the time, the transmitters were heavy ground-based units that you controlled by a switch on an extension cord. They often required fancy electronics at the time to get as much as 135 Volts for the plate supply. I've read of early RC expirementers who had small dynamos (Generator sets) as part of their field equipment or built into their cars. I don't think any RC radio gear was available commercialy untill near the end of WW2.

We have things a LOT easier, cheaper, and more dependable.

Not radio but around that time Jim Walker of control line fame had a glider controlled by sound. Apparently one shouted at it and the sound was picked up by either one of two microphones placed in each side of the fuselage. The dominant mic then relayed a signal to the rudder. Hmmmm!
Copies of Chester Lanzo's circuits may be seen in the 1938 model Aeronautics Yearbook from Frank Zaic where Chester claims he is still working on one of these units where the transmitter weighs 10oz unit and is fitted in the plane but the receiver is fitted it in a car and no control is effected but hopefully the plane will not be lost. In the same yearbook a practical circuit is shown from Ross A. Hull and even includes a diagram of an escapement.

A good ten years ago, I purchased one of those books printed inthe late 1920's dealing with "Secrets" of the early time modelers. One such chapter pictures and describes a rather huge glider of about 10 foot span. Most of the article is about the model construction, and only last paragraph tells of the radio gear. For as it mentioned, radio was experimental, not addressed to properly by the Govt. depts. and thus illegal for amature use. But none the less in the lead off picture, they showed this huge glider about to touch down within eyesight of the fellow and ground based transmitter. Was some mention to look forward to the author offering a powered version of same airplane in future article.

I think the Lanzo may have been most popular, but it wasn't the first for according to the reprint, it had been done ten years earlier.

Wm.