Fail-safe is suppose to work as long as you recorded a home position prior to taking off. However,
if you get interference that over powers your transmitter then basically your Phantom is about to do whatever that interference tells it to do. If eventually the Phantom realizes that it is indeed listening to interference it will then go into fail-safe and return home.
An upgraded Tx simply provides better protection against interference Vs. the stock Phantom Tx.
Phantom 1 and 2 (not Vision) uses 2.4 GHz which is the same frequency things like wireless routers use so there is potential interference almost everywhere. Also line of sight is always best but 2.4 GHz does not rely on line of sight as much as other frequencies do, the lower the frequency the bigger the wave length, the bigger the wave the shorter range but better at going through objects.
Also, although I cannot say Flyaways are COMMON I do know that they do sometimes happen, and that's enough to make me paranoid using the stock Tx.
ghinson said:
How common are fly-aways with the stock Tx, especially flying in line of sight? And, if it ever happens, would fail-safe be, well, a fail-safe?