Hey guys, I discovered the trick for my P4 , the RC has a very narrow angle of transmission, at least mine does, if I tilted the transmitter up ever so slightly I lost signal, same thing tilting it down ever so slightly, I would lose signal. so when I found just the right place to hold the transmitter I was able to maintain signal out to over 16k. My two P3P's do not seem to be so sensitive with the angle of the RC during distance flights. My best flight so far, I had a blast !! This is stock, no windsurfer, nothing !!