Cirrus compromised by turbulence

This September 2010 accident report is provided by the National Transportation Safety Board. Published as an educational tool, it is intended to help pilots learn from the misfortunes of others.

Aircraft: Cirrus SR22. Injuries: 1 Serious, 1 Minor. Location: Mathias, W.Va. Aircraft damage: Substantial.

What reportedly happened: The pilot was near the end of a two-hour cross-country in IFR conditions. He was flying a holding pattern around the initial approach fix and waiting for the weather conditions at the destination airport to improve.

While holding, the pilot learned winds were calm on the surface but higher up were wind gusts of up to 40 knots in turbulence aloft. After holding for about 15 minutes, he decided to execute the instrument approach. While descending to the final approach fix, the airplane slowed, the turbulence worsened, and the autopilot disengaged.

Following several pitch and roll oscillations, the pilot lost control of the airplane. During the resulting dive, the plane pitched to an attitude of 86° nose down, reaching a maximum airspeed of 171 knots and 3.29 Gs. The pilot successfully activated the whole-airframe ballistic recovery parachute system. The airplane came to rest in the woods, 25 feet above ground, about 10 nautical miles from the destination. The specific reason for the autopilot disengagement was not determined, although it was likely due to a very brief activation of the stall warning or an inadvertent manual disengagement.

The forecasted weather for the flight included widespread instrument meteorological conditions and turbulence above the destination airport, and an adjacent area of forecasted convective weather, temperature inversion, and associated wind shear. Weather radar imagery of the immediate area of the accident site, about the time of the accident, included areas of light to moderate intensity precipitation.

Probable cause: The pilot’s loss of control during an instrument approach in turbulent weather conditions.

For more information: NTSB Identification: ERA10LA506

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