For planes that I use a UBEC, there two methods: 1). On the linear BEC that comes with the esc, disconnect the middle(red) wire and just plug in the UBEC to the throttle port. or 2). Use a Buss-Tie circuit (Shottky) . With this setup, you use both the on board linear BEC and the UBEC. A redundant system. If one fails, the other takes over. pretty cool. Here's a write up on it. A guy over on RCG made up a couple from me as I'm not an electronic wiz.