DRAGONFLY N402HA accident near Ridgely, Maryland

Probable cause

An in-flight loss of control for reasons that could not be determined during postaccident examinations.

NTSB analysis

The flight instructor who was towed aloft by the tow airplane with his student in a tandem hang glider reported that the airplane did not lift off until it was near the end of the grass runway. A witness reported that, after the airplane released the glider, it began to turn left while climbing until it completed a 270-degree turn, reached a peak altitude of about 270 feet above ground level, then entered a spin, rotated one to two times, and subsequently impacted the ground.

Postaccident examination of the engine revealed no evidence of any preimpact failures or malfunctions that would have precluded normal operation. Further, no evidence was found indicating that a flight control malfunction occurred or that the tow rope became entangled. During examinations, one of the airplane's bracing cables, which strengthened and stiffened the airplane's structure and normally extended from the upper surface of the right wing to a plate above the tailwheel, was found on the ground beneath the right wing with both of its ends broken from the airplane structure attachment points. The cable had fractured in overload in the eye splice sleeves at both ends. Although failure of this cable might have distorted the airplane's structure in flight and resulted in controllability challenges, it could not be determined if the cable failed in flight or during the impact sequence. It is also possible that the pilot became distracted during the climb while watching the hang glider after the release and allowed the airspeed to degrade, which resulted in an aerodynamic stall and subsequent spin.

Text from the NTSB. Open the NTSB docket for ERA11FA413 for the full record.