I flew a new plane today (a CL Slow Combat plane converted to RC) and got full down un-commanded inputs about three times in a 1 minute flight, the last two as I was trying to get on the ground. 'Survived, but wasted some heartbeats.

Belatedly . . . I did a range check and at about 50 feet, with the antenna down, I was getting chattering and un-commanded down elevator.

The receiver came out of another plane where it was working fine.

Where should I start on my efforts to correct this?

Was there anyone else at the field?

I am on channel 43. A few weeks ago this kid and his dad had ths ancient radio and was on 44. Luckily he turned his radio on BEFORE I was airborn and could see my plane going crazy.

It could be interference like that.

No, I was alone at the time.

Is the antenna ok? No bad spots? on the rx

First double check that everything is hooked up and plugged in. Espeically the RX crystal. A loose RX crystal can drive you nuts. (been there).

Unplug some of the servos, and range check with just one servo at a time plugged in. It's rare, but possible that a servo is freaking out on you.

Most likely, your RX antenna has a problem. First, try relocating it on the plane. If that tail boom is CF or metal, get the antenna away from it, try running it to the tip of the vertical stab or out along the wing.

If re-doing the orientation didn't help, check the antenna. You might even open the RX case (if it has one) to see if the antenna is still attached. It's possible the antenna is broken, but the break is internal, and not visible. You might be able to feel it if you run your fingernail down the antenna (being careful not to tug on it, or cause any harm).

You didn't cut the antenna, did you? Or bundle up "extra" antenna? In the second picture, your anenna looks shorter than I'd expect.

I'd look for metal to metal vibrations. Since this was a contol line airplane, I suspect some of the controls may be metal to metal linkages as it would make no difference in the CL. Be sure there isnt a screw or loose metal vibrating around.

You didn't mention if the poor range was with the engine running or with it off.

I agree, metal-to-metal contact can be a killer.

You should check the range with the engine off, then again with the engine running. If you get much of a drop in range, then you need to figure out why and do something about it. In that case, metal to metal contact is good place to look.

Oh, I also forgot to mention, try to avoid having the antenna routed too close to any servo or battery leads. When it leaves the RX, try to get it away from the rest of the wires, and keep it away from them.

Hmmmmm, airtronics?

Check the rx with different servos, also a different switch. Might be a cracked antenna in the rx though.