Pilot Debrief

KNELL ASC SPIRIT near Lehi, UT — 2014-06-22

Final reportWPR14LA263
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Date
2014-06-22
Location
Lehi, UT, USA
Airport
UT10
Aircraft
KNELL ASC SPIRIT
Registration
N127JK
Category
Glider
Highest injury
Fatal
Fatalities
1
Phase of flight
Approach

Probable cause

The pilot’s exceedance of the glider’s critical angle of attack while maneuvering in a steep turn at low altitude, which resulted in an aerodynamic stall.

NTSB narrative

The private pilot of the experimental, amateur-built glider was conducting a local flight. The tow plane pilot reported that, as the glider pilot approached the privately owned airport, he announced over the radio his intent to land. He and one witness in the area reported seeing the glider circling to land and making several steep turns during the descent. When the glider was about 30 to 40 ft above ground level, the nose suddenly dropped, and the glider then descended straight down into the ground short of the runway. Another witness reported that it looked like the glider had stalled. Wreckage documentation indicated that the glider impacted terrain in a steep, nose-down, left-wing-low attitude with little forward motion, which is consistent with a stall. Postaccident examination of the airframe revealed no anomalies that would have precluded normal operation. It is likely that the pilot exceeded the glider's critical angle of attack while maneuvering to land, which resulted in an aerodynamic stall.

Analysis

Primary failure mode
Loss of control
First missed decision gate
Pilot could have opted for a go-around instead of continuing steep turns to land.

NTSB coding

Evidence available

  • Photos
  • 8 docket documents
View NTSB final reportView NTSB docket

Docket documents8

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