I have lost drones after taking off, but it is do to me not managing my climb and/or air speed until the drones latch on to me real good. If you take off from a field with a hill at the end of the runway and have to make a turn soon after take off, it is real tough keeping them together. I suggest paying attention to what obsticles are in your path before deciding to take off.
If your talking about when you have been flying awhile and trying to keep them with you in a tight turn. Try opposite full rudder to the direction you are turning. Keeps a nice tight formation and unless you trying some radical turn the drones will stay nice in tight with you.