Years ago during early trials of the 330 Puma they would wire the yaw channel with a switch that would cause it to go to open loop; i.e. throw the actuator full over. They would then load the aircraft so it was at the aft CofG, get airborne and dive it at VNE 310 k/h and throw the switch.
Aaaaaaaaand one, aaaaaaaaand two.
Then recover from the inverted.