A passenger on board the aircraft, said that the measured length of the airstrip was 1,000 m, with trees on the left and open grasslands on the right. He said the airstrip surface was rough to the left of the centreline for almost the entire length. The airstrip also had a slight uphill gradient in the takeoff direction. The passenger stated that he had taken a short flight with the pilot earlier the same day. He said that during the accident takeoff the aircraft was further to the left of the runway centreline than on the previous occasion, and it appeared to accelerate more slowly. At a height of about 100 to 120 ft above ground level, the stall warning horn sounded and the aircraft began to descend towards the trees to the left of the strip. The left wing then clipped a tree and the aircraft descended to impact the ground nose first. The investigator was unable to obtain details of the accident from the pilot in command.