I saw something a while ago in the back of one of my mags that showed a card like device you could use to tell how fast a plane was traveling. It also showed a bigger version that could be set up on the flight line, I think. It was used by calculating time to distance to see how fast a model is going.

Does anyone know what and where this is?

I can't find it now.

Thanks,
Shaun

im not sure exactly what that might be if its a time/speed/distance calculator.

The only devices I know of to get decent speed measurements are radar guns and on-board air data recorders.

Bob

I saw some info on calculating speed using a sound recording of the engine as it passed by a microphone. You could record the sound on your computer and the program would calculate the speed by using the Doppler effect. I can't seem to find the info now that I have a use for it.

Nashcat

I didn't read through the entire article, but this sounds similar: http://www.alphalink.com.au/~hughan/speed.htm

I think this is interesting, but what I was referring to was a very simple card that you look through. I remember seeing it in one of my magazines but just can't find it. Was just hoping someone here would have known exactly what it was.

Thanks,
Shaun