What two primary factors must be present for an aircraft to spin?

What two primary factors must be present for an aircraft to spin?

• A. Stalled AOA and yaw
• B. Stalled AOA and roll
• C. Maximum torque and yaw
• D. Minimum torque and roll

Answer: (A)

For an aircraft to enter a spin, two essential factors must be present: a stalled angle of attack (AOA) and yaw. When an aircraft is at a stalled AOA, it means that its wings are no longer generating sufficient lift, creating an unstable aerodynamic condition. This stall condition is critical because, without it, the aircraft cannot produce the necessary differential lift over the wings that leads to the spin. Simultaneously, yaw must occur, which typically happens when one wing experiences a higher wing loading than the other due to an uncoordinated turn or excessive control input. This yaw causes the aircraft to rotate around its vertical axis, and combined with the stalled condition, it leads to a spinning action. Therefore, both the stalled AOA and yaw are crucial conditions that initiate a spin, making this choice the correct characterization of the phenomena involved in an aircraft spin.

For an aircraft to enter a spin, two essential factors must be present: a stalled angle of attack (AOA) and yaw. When an aircraft is at a stalled AOA, it means that its wings are no longer generating sufficient lift, creating an unstable aerodynamic condition. This stall condition is critical because, without it, the aircraft cannot produce the necessary differential lift over the wings that leads to the spin.

Simultaneously, yaw must occur, which typically happens when one wing experiences a higher wing loading than the other due to an uncoordinated turn or excessive control input. This yaw causes the aircraft to rotate around its vertical axis, and combined with the stalled condition, it leads to a spinning action.

Therefore, both the stalled AOA and yaw are crucial conditions that initiate a spin, making this choice the correct characterization of the phenomena involved in an aircraft spin.