Accident Description
The pilot of an experimental, amateur-built biplane reported that during a normal initial climb, approximately 100 ft above ground level, the aircraft began an un-commanded turn to the left followed by a descent. Recognizing that the flight path was heading toward a tree line, the pilot attempted to climb to clear the trees but nearly stalled and could not avoid impact. The biplane subsequently struck the trees, resulting in substantial damage to the wings and fuselage.
Weather Information
Automated weather observation at the airport around the time of the accident indicated wind from 360° at 5 knots. The pilot was departing on runway 03. The calculated density altitude was 1,897 ft.
Pilot Comments
The pilot stated there were no preaccident mechanical failures or malfunctions that would have precluded normal operation. He added that the biplane is "not very stable once in a flying configuration" and that any change in air mass (gusts) can disturb the balance, resulting in self-induced turns, climbs, and descents. He noted that these movements must be countered immediately due to the relatively small control surfaces (rudder, ailerons) and that corrections are slow, potentially causing loss of altitude. He emphasized that pilots expect these upsets and remain alert for them.