QUOTE FROM MANUAL
The PCM 1024Z system also provides you with an advanced battery monitering function that warns you when the reciever battery has only a little power remaining. In this case, the throttle is moved to the defined failsafe postition, or if one was not defined, to a medium speed position.The throttle may be released by operating a predefined control on the transmitter (the default is throttle), do not continue to fly.