How is a "spin" defined in the context of aircraft flight?

In the context of aircraft flight, a "spin" is specifically defined as a controlled stall that results in the aircraft rotating around its vertical axis. During a spin, one wing is more stalled than the other, which causes the aircraft to enter into a descending spiral. This phenomenon is characterized by a specific and distinct aerodynamic condition where the aircraft's yaw and roll are coupled due to the differential lift created by the wings.

When an aircraft enters a spin, the pilot needs to apply specific recovery techniques to regain control, as spins can be particularly dangerous if not managed properly. The correct understanding of spins is critical for pilots, as it involves understanding aerodynamics, control surfaces, and recovery procedures.

Other definitions do not capture the nuances of a spin. For example, a rapid descent toward the ground does not necessarily indicate a controlled stall or the rotational aspect of a spin. Similarly, an uncontrolled dive may involve a loss of control, but it does not involve the rotational dynamic characteristic of a spin. Finally, a maneuver used for landing refers to established landing techniques, which is unrelated to the stall and spin scenario being defined. Thus, the accurate characterization of a spin is essential for recognizing the specific challenges it presents during flight.