Schweizer SGS 1-23D N91896 accident near Aberdeen, Maryland

Probable cause

The pilot's loss of control during an intentional aerobatic maneuver (spin) resulting in a collision with trees.

NTSB analysis

According to the pilot, on his second flight of the day, he initiated a spin to the right around 3,200 feet. After approximately three-quarters of a turn, he attempted to recover from the spin by applying left rudder. He felt no resistance upon application of the rudder and the glider felt unresponsive. As he neared the ground, the pilot was able to maneuver toward trees. The glider impacted a tree, resulting in substantial damage to the wings. The glider remained in the tree for several days due to snow and ice storms before it could be recovered. A postaccident examination by a Federal Aviation Administration inspector revealed that the rudder turnbuckles were set per the maintenance manual and the rudder return springs were intact and not stretched. The rudder controls functioned properly when manipulated.

Text from the NTSB. Open the NTSB docket for ERA11CA087 for the full record.