The movement about the longitudinal axis caused by cyclic input right or left causes the helicopter to tilt in that direction.

• A. Aircraft Roll
• B. Airfoil
• C. Aircraft Pitch
• D. Agonic Line

Answer: (A)

Rolling about the longitudinal axis happens when you move the cyclic to the left or right. That lateral cyclic input tilts the rotor disk in the same direction, so the helicopter banks toward that side. As the rotor disk tilts, one side of lift increases while the other decreases, causing the fuselage to roll (bank) in the direction of the input. This is why the movement described is called roll.

For context, pitch is a different motion—rotation about the lateral axis—caused by forward or backward cyclic to tilt the rotor disk nose-up or nose-down. The agonic line is unrelated here, as it’s a magnetic-reference concept, and an airfoil is simply a lifting surface, not a motion about an axis.