Don't know about heli stuff that much but i have seen that happen more than one time in airplanes -- both glow and glider models. It's at an orientation where you have the least area of the antenna at the receiver exposed to the transmiter. Also, I have noticed that many guys tend to do all kinds of cute things with antenna wires to take up the excess wire, all of which amounts to seriously affecting the ability of the receiver to receive! I may not know about RC, having only been in it 17 years, but I do know about radios and antennas, being an Extra Class ham operator. The importance of antenna orientation and resonance cannot be overstressed. Needless to say, there's no wonder why the experts tell you to always perform a range check, assisted by someone who can re-orient the model for you while you stand away the suggested distance. Also, many guys never do a range check with an engine running, which can change everything if you have any metal - to - metal parts that are vibrating when the engine is running.

Hope that helps some and very sorry to hear about your bad luck.