North Wing Uum Inc SPORT X2-N N366DN accident near Boulder City, Nevada

Probable cause

The student pilot’s exceedance of the weight-shift-control aircraft’s critical angle of attack and the flight instructor’s delayed remedial action and failure to maintain the proper airspeed after encountering localized turbulence during approach, which resulted in an aerodynamic stall.

NTSB analysis

The student pilot of the weight-shift-control aircraft reported that, while practicing touch-and-go landings on a dried lake bed, the flight instructor was controlling the throttle inputs, and she "controlled the wing." She added that, just before the accident, she observed three dust devils to the east and that, during a final pass near the north end of the lake bed, they came upon "strong localized turbulence." The aircraft impacted the ground and rolled to the left.

The flight instructor reported that, during the turbulence encounter "about 4-6 ft" above the ground, the "wing stalled," which resulted in a "hard nose wheel landing."

The weight-shift-control aircraft sustained substantial damage to both wings.

The flight instructor reported that there were no preaccident mechanical failures or malfunctions with the weigh-shift-control aircraft that would have precluded normal operation.

The flight instructor reported that the wind was light and variable and that the temperature was 70°F at the accident location. A review of recorded data from the automated weather observation station located about 6 miles northeast of the accident site reported that, about the time of the accident, the wind was calm, and the temperature was 64°F.

Text from the NTSB. Open the NTSB docket for GAA17CA250 for the full record.