There is built-in checkout system for low voltage protection.With MCU technology to check the voltage of the lithium battery,the low-voltage protection function will be activated when the voltage is lower than 6.4V+/-0.2V.However,the rudder still functions to allow the airplane to land safely by the player.The MCU low voltage protection function can be deactivated by pushing the throttle back to zero.The airplane can be operated by pushing the throttle again.