Amateur-built GLASAIR III N7SY accident near Winchester, Tennessee

Probable cause

The pilot's inadvertent climb and entry into instrument meteorological conditions during a course reversal, which resulted in spatial disorientation and a loss of control.

NTSB analysis

The accident airplane was one of two airplanes on a multi-leg, cross-country flight. The airplanes were operating at 2,500 feet mean sea level (msl), at 200 knots, with an overcast cloud layer about 300 feet above them. The pilots encountered deteriorating weather conditions about 40 miles prior to a planned fuel stop. The lead pilot turned to its left, and according to data extracted from the GPS receiver on board, the accident pilot initiated a climb, and then a course reversal to the right. During the turn to the right, the airplane climbed to nearly 3,800 feet, slowed to 144 knots, descended to 2,000 feet and accelerated to 255 knots, climbed back to 4,000 feet and slowed to 39 knots at the second-to-last data plot which was in the vicinity of the crash site. Two witnesses said they heard the airplane, and one witness observed it before ground contact. Examination of the crash site and the wreckage revealed damage to the trees and the airplane that were consistent with a near vertical descent and engine power at impact. The pilot of the lead airplane stated that he checked the weather prior to their departure, and that the weather conditions were clear all the way to their destination. However, AIRMETs for icing conditions from the surface to 10,000 feet, as well as for mountain obscuration due to clouds and precipitation were current along the planned route of flight in the area surrounding the accident site. The airplane's rapid, near-vertical descent, turning ground track and the meteorological conditions are consistent with the pilot's loss of control of the airplane due to spatial disorientation.

Text from the NTSB. Open the NTSB docket for ERA11LA048 for the full record.