Which set of actions constitute the three conditions required for dynamic rollover to occur?

Which set of actions constitute the three conditions required for dynamic rollover to occur?

• A. Establish Pivot point; Initiate Rolling Motion; Exceed Critical Angle
• B. Initiate Rolling Motion; Establish Pivot point; Exceed Critical Angle
• C. Initiate Rolling Motion; Establish Pivot point; Maintain Level Attitude
• D. Establish Pivot point; Exceed Critical Angle; Initiate Rolling Motion

Answer: (C)

Dynamic rollover happens when a helicopter on the ground begins to roll about a contact point and gravity then drives the roll into a rapid, uncontrolled motion. The three conditions that make this possible are: the rolling motion has to start, a pivot point must be established at a ground contact so the helicopter can rotate about it, and the attitude must remain such that gravity continues to act to increase the roll rather than restore the upright position. Once the body is rolling and a pivot is in place, keeping the fuselage level prevents an immediate corrective moment from re-centering the aircraft, allowing the gravitational tendency to dominate and the roll to accelerate toward a full rollover. If any of these steps are missing—no initial roll, no pivot, or an attitude that counteracts the roll—the dynamic rollover is unlikely.

Dynamic rollover happens when a helicopter on the ground begins to roll about a contact point and gravity then drives the roll into a rapid, uncontrolled motion. The three conditions that make this possible are: the rolling motion has to start, a pivot point must be established at a ground contact so the helicopter can rotate about it, and the attitude must remain such that gravity continues to act to increase the roll rather than restore the upright position. Once the body is rolling and a pivot is in place, keeping the fuselage level prevents an immediate corrective moment from re-centering the aircraft, allowing the gravitational tendency to dominate and the roll to accelerate toward a full rollover. If any of these steps are missing—no initial roll, no pivot, or an attitude that counteracts the roll—the dynamic rollover is unlikely.