Spin (flight)

In flying, a spin is a special case of stall. In this state, an aircraft is not flying, but falling - the wing is not generating sufficient lift to support the aircraft as with a normal stall, but in addition, in a spin, the aircraft is rotating about its yaw axis.

A spin may occur when a stall occurs that affects one wing significantly before the other, which can happen during a turn or other manoeuvre. An aircraft may be deliberately spun for purposes of training, test flying and aerobatics. A spin is usually entered by flying the aircraft into a stall condition by pitching upwards and reducing power. As the stall point is reached, the rudder is used to yaw the aircraft rapidly. The outward wing will keep flying, the inner one will stall and the aircraft will enter a spin. Some aircraft are naturally stable and the controls will need to be held until the spin is fully developed.

A spin in which the aircraft is still essentially the right way up (though falling in a very nose-down attitude) is called a normal or upright spin, one in which it is inverted is called an inverted spin.

Spinning is often feared by pilots, especially novices, and spin recoverey is no longer a compulsory part of the PPL syllabus. However, it makes good sense for every pilot to know how to get out of a spin should it occur. Practice makes this much easier, because the sensation of spinning is generally pretty unpleasant and without familiarity, can seem like total chaos.

Spin recovery

Because a spin is a form of stall - a fact that eluded many pioneer aviators until spin recovery was discovered sometime in the 1910s - the key thing is to get the wings flying again. However, the spin rotation should first be arrested so that both wings can contribute fully to the recovery. The pilot should assess the spin direction and apply opposite rudder until the rotation stops. At this point the control column should be moved forward to reduce the angle of attack. As the aircraft pitches down, the wing will become unstalled and start to generate lift. At this point the aircraft will be in a steep dive and probably going very fast. The pilot must then ease out of the dive taking care not to exceed the g-stress rating of the aircraft. Pulling up too sharply can result in mechanical failure or another stall. Naturally, spin recovery can require a considerable height.