I told you about the 1/4 scale F4 we saw crash out at Camp Parks in Dublin, right?
It was making an inverted pass down the runway at an all-jet R/C airshow when his radio went into fail-safe (i.e. the plane stopped recieving instructions from the transmitter). Usually fail-safe would allow the plane to circle in a slow climb waiting for the radio to make contact... but in a low altitude inverted pass, it results into a nice slow lawn-dart followed by a nice big fireball.
That's a $10,000 loss of communications. "Can you hear me now?"