So today I saw another plane that makes a funny noise when the motor is stopped. I don't know exactly how to describe it, but I joked that his plane would fly better if he got the guitar out of it. Sounds like someone plucking one guitar string really hard. Every time the motor stops. I think i've only seen it on larger models. Any idea what it is? Is it bad? And how do you get rid of it if you have to? Thanks!