The pilot was completing an approach to runway 10 at the time of the accident. The wind was reported as blowing from 060 degrees at 10-15 kts. At a height of approximately 30 ft the aircraft was observed to roll and yaw to the left of the runway centreline. In what appeared to be an attempted correction by the pilot, the aircraft was observed to roll and yaw to the right. At a height of approximately 15 ft it was observed to turn back to the left and track, in a nose high attitude and with decreasing airspeed, towards trees to the north of the runway. The aircraft collided with the trees and came to a stop in a nose-down position. The pilot reported that the atmospheric conditions were turbulent, with a crosswind and some wind shear evident during the approach. He had decided to use only 20 degrees of flap for the landing because of the conditions. At approximately 30 ft the aircraft was affected by a sudden wind gust which caused it to turn left and away from the runway. He tried to correct and applied power to commence a go-around but the aircraft continued to descend. He retracted the flap in an attempt to improve the aircraft's performance but this aggravated the situation. He was unable to prevent the collision.