Schweizer 269C-1 N21086 accident near Stuart, Florida

Probable cause

The student pilot's inadvertent activation of the collective control, which allowed the helicopter to become airborne and impact the ramp.

NTSB analysis

The pilot completed a cross-country instructional flight with his flight instructor. After landing on the ramp, the flight instructor exited the cockpit and set the collective friction. The student pilot then set the cyclic friction. The flight instructor transferred aircraft control to the student pilot and asked him to remain in the cockpit while the engine cooled down. As the flight instructor was leaving the immediate area, he observed the helicopter become airborne and enter a spin. The helicopter then impacted the ramp and came to rest on its right side. A postaccident examination of the wreckage revealed no evidence of pre-existing mechanical failure or malfunction. The cyclic and collective friction adjustments operated normally after the accident. Although the pilot stated that he did not initiate the event, the evidence suggests that the helicopter became airborne because of manipulation of the flight controls by the pilot.

Text from the NTSB. Open the NTSB docket for ERA11LA116 for the full record.