Primary finding
Probable cause
The pilot's failure to maintain adequate airspeed during the landing which resulted in a stall.
Investigator assessment
Analysis narrative
The glider sustained substantial damage while landing when the left wing and fuselage impacted terrain. The pilot sustained serious injuries. A police report stated, "[The pilot] said while he was turning, he forgot to monitor his air speed and the glider fell below the minimum speed, which caused his left wing to stall. [The pilot] said his left wing hit the ground during the turn and caused the glider to somersault onto the gliders belly and spin. The pilot stated that there were no mechanical malfunctions or failures. The wind was 160 degrees at 7 knots.
Source record
Factual narrative
On July 29, 2001, about 1600 central daylight time, a Burkhart Grob G102 STD ASTIR III, N3837U, piloted by a private pilot, sustained substantial damage when the glider's left wing and fuselage impacted terrain at Faribault Municipal Airport (FBL), near Faribault, Minnesota. The personal flight was operating under 14 CFR part 91. Visual meteorological conditions prevailed at the time of the accident. No flight plan was on file. The pilot sustained serious injuries. The local flight departed from FBL at 1510 and was landing at the time of the accident. In his written statement, the pilot noted: Abreast of the landing point I verified that I was approximately 800 feet Agl [above ground level]. Proceeded to normal left turns for Base Leg and Final Leg and announced. The initial Final Glide was done using 1/2 spoiler setting. On approaching Hwy. 21 I encountered strong lift and started using full spoiler setting. At the intersection of runways 20 and 30 I became very concerned about my altitude and decided that landing on Rwy 20 was no longer possible because of the tall trees at the end of the Runway. I decided to execute a 270-degree turn to my left to loose altitude and allow me to land on the remaining portion of Rwy 30. At this point, I became fearful of the outcome of this flight. I did not loose consciousness but do not remember anything from the time of initiating the turn, up to the final contact with the ground. A Rice County Law Enforcement incident report stated: [The pilot] said while he was turning, he forgot to monitor his air speed and the glider fell below the minimum speed, which caused his left wing to stall. [The pilot] said his left wing hit the ground during the turn and caused the glider to somersault onto the gliders belly and spin. The pilot stated that there were no mechanical malfunctions or failures. At 1557, the FBL weather was: Wind 160 degrees at 7 knots; visibility 10 statute miles; sky condition clear; temperature 29 degrees C; dew point 19 degrees C; altimeter 29.93 inches of mercury.