Dynamic rollover

A helicopter is susceptible to a rolling tendency, called dynamic rollover, when close to the ground, especially when taking off or landing.

If the critical rollover angle is exceeded, the helicopter rolls on its side regardless of the cyclic control corrections made.

Dynamic rollover may also occur if the pilot does not use the proper landing or takeoff technique or while performing slope operations.

Dynamic rollover can occur in both skid and wheel equipped helicopters, and all types of rotor systems.

When the rotor blades stop, the helicopter has the same principles of any other object and will roll if the static rollover critical angle is exceeded.

Dynamic rollover critical conditions: The forces acting on a helicopter with counterclockwise rotor rotation, and the right skid on the ground. The critical rollover angle is 5°-8°. Once exceeded, main rotor thrust continues the roll, and recovery via cyclic control is impossible. [ 1 ]