This thread is the continuous of “Knowing the Throttle Curve and Pitch Curve 1”. After reading this you will know how a helicopter can fly upside down.
From the figure you can see the pitch is variable from -9 to 9 degree. In the middle point is the zero pitch position. For the throttle curve is increasing from 50% (middle point) to 100% (minimum & maximum point).
How the pitch help to perform upside down flight? For normal flight the positive flight will generate an up thrust force. Then the negative pitch will generate a downward force. Imagine that you are holding you helicopter upside down, the 25% stick position. -4.5 degree pitch with 75% throttle will allow the helicopter fly upside down.
Knowing their stunt mode operation is important, if you don’t know the curve and switch to the stunt mode, the throttle is non-stop and the pitch is variable and the blade sometime provide upward force, sometime provide downward force.
Doing the upside down flight is not an easy task, as the rudder and aileron is totally reverse, so you need to hovering your helicopter very well before jumping to the next step.