GPS Failsafe Event. What Happens?


I tried reading all of the Arduplane documentation, and have yet to understand what exactly will happen when a plane in flight loses GPS.

States it will “Dead Reckon” for how long? Will it continue an Auto Mission in this manner? I have unplugged the tx and rx wires on the gps unit to try to simulate a loss of GPS and I get a message: “EKF2 is no longer aiding”

I am trying to understand what will actually happen if my GPS fails in flight so I know how to react. Could anyone link me to an explanation of what will happen.