Originally Posted by Larry G
Be wary of that E-Flite ESC in your bird. I saw one burn out today in my friends Apprentice. I have also seen a few Apprentices fall from the sky for unexplained reasons and we are thinking that ESC is not a good one. Spend 20 bucks of insurance and get a Castle UBEC so you can at least glide it in when that ESC lets go.
My pal has a PZ Corsair with that ESC and was having loss of control issues intermittantly. He replaced the stock E-Flite ESC with a 40 amp Turnigy Plush and it has not glitched since.
Even though your post is over a year old, it has good advice. I had the same problem and then took your advice and went with UBEC's. It cured all my hot and failing ESC problems.