21 Jun 2023: LET L-23 SUPER BLANIK (N10BR) — SANDHILL SOARING CLUB INC — Gregory, MI

No fatalitiesGregory, MI, United States

A Let L-23 Super Blanik instructor and student pilot were injured when the glider stalled during an attempted off-field landing.

What happened

On June 21, 2023, at approximately 15:30 EDT, a LET L-23 Super Blanik, registration N10BR, was involved in an accident near Richmond Field Airport (69G) in Gregory, Michigan. The flight was being conducted as a Part 91 instructional flight.

According to the student pilot, the instructor took control of the aircraft approximately 10 minutes before the accident to search for thermals. The student reported that the instructor eventually announced an intention to perform an off-field landing. The glider crossed a tree line at approximately 150 feet above ground level before turning toward a bean field. The aircraft came to rest about 3,5able 500 feet northwest of the north end of the runway. The instructor sustained one serious injury, and the student sustained one minor injury.

The investigation

Post-accident examination of the aircraft revealed substantial damage to the fuselage and both wings. The forward fuselage was crushed upward and rearward, and the outboard 6 feet of the left wing had separated from the aircraft. Analysis of the separation point showed signatures indicating the wing tip had bent upward. The damage pattern was consistent with a nose-low, left-wing-low impact. Investigators verified flight control continuity from the cockpit to all control surfaces and found no pre-impact anomalies.

Probable cause

The flight instructor failed to maintain adequate airspeed and exceeded the glider's critical angle of attack, resulting in an aerodynamic stall during the off-field landing attempt.

Contributing factors

Capability exceededInstructor/check pilot