Spin (flight) - History

History

In aviation's early days, spins were poorly understood and often fatal. Proper recovery procedures were unknown, and a pilot's instinct to pull back on the stick served only to make a spin worse. Because of this, the spin earned a reputation as an unpredictable danger that might snatch an aviator's life at any time, and against which there was no defense.

The spin was initially explored by individual pilots performing ad-hoc experiments (often accidentally) and by aerodynamicists. Lincoln Beachey was able to exit spins at will according to Harry Bruno in Wings over America (1944). In August 1912, Lieutenant Wilfred Parke RN became the first aviator to recover from an accidental spin when his Avro biplane entered a spin at 700 feet AGL in the traffic pattern at Larkhill. Parke attempted to recover from the spin by increasing engine speed, pulling back on the stick, and turning into the spin, with no effect. The aircraft descended 450 feet, and horrified observers braced themselves for a fatal crash.

Parke was disabled by centrifugal forces but was still considering a means of escape. In an effort to neutralize the forces pinning him against the right side of the cockpit, he applied full right rudder, and the aircraft leveled out fifty feet above the ground. With the aircraft now under control, Parke climbed, made another approach, and landed safely.

In spite of the discovery of "Parke's technique," spin-recovery procedures were not a routine part of pilot training until well into World War I.

The first documented case of an intentional spin and recovery is that of Harry Hawker. In the summer of 1914, Hawker recovered from an intentional spin over Brooklands, England, by centralizing the controls.

In 1917, the English physicist Frederick Lindemann conducted a series of experiments that led to the first understanding of the aerodynamics of the spin.

During the 1920s and 1930s, before night-flying instruments were commonly available on small aircraft, pilots were often instructed to enter a spin deliberately in order to avoid the much more dangerous "death spiral" when they suddenly found themselves enveloped in clouds, hence losing visual reference to the ground. In almost every circumstance, the cloud deck ends above ground level, giving the pilot a reasonable chance to recover from the spin before impacting the surface.

Today, spin training is not required for private pilot certification; added to this most training type aircraft are placarded "intentional spins prohibited". Some model Cessna 172's are certified for spinning, although they can be difficult to actually get into a spin. Generally though spin training is undertaken in an "Unusual attitude recovery course" or as a part of an aerobatics endorsement (though not all countries actually require training for aerobatics). However, understanding and being able to recover from spins is certainly a skill that a fixed wing pilot could learn for safety. It is routinely given as part of the training in sailplanes, since gliders often operate slowly enough to be in turning, near-stall conditions. Because of this, in the U.S. demonstration of spin entry and recovery is still required for glider instructor certification.