Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 15; Flight Crew Total 30000; Flight Crew Type 65
Confusion; Distraction
Ground Event / Encounter Object; Ground Excursion Runway; Inflight Event / Encounter Loss Of Aircraft Control; Inflight Event / Encounter Wake Vortex Encounter
Aircraft Aircraft Damaged; Flight Crew Took Evasive Action
Aircraft; Environment - Non Weather Related; Weather
[I was flying a] Sonex; conventional gear; (tail wheel). During takeoff after tail was in the air; for what ever reason; combination torque and crosswind; the aircraft began a turn to the left. [I] was unable to correct to the right because this aircraft does not have differential braking and did not have enough wind to have rudder authority. Braking with the tail in the air; trying to avoid a ridge along side of runway came in contact with a runway light. Only damage was to the ends of the propeller from contact with the sand and grass. No injuries. The takeoff was a 'rolling' takeoff and most likely there was some wake turbulence from an earlier takeoff of larger plane. (AT-6). Not having differential braking and not feeling comfortable trying to put the tail down while trying to use max braking caused lack of directional control.
A Sonex turned left off the runway during the takeoff roll because of torque and crosswind. Unable to stop; the pilot continued as his propeller struck sand and grass before liftoff.