The aircraft was taking off from a bush strip. The pilot said that the takeoff run took about 600 m of the 800 m available. However, the aircraft failed to climb away so the pilot rejected the takeoff at a late stage. The aircraft was landed beyond the end of the strip, amongst saplings and trees. The pilot attributed the lack of performance to a partial power loss, although he had not heard a change in engine note, nor had he noticed any abnormal engine indications. During subsequent testing of the engine, full power was able to be achieved. Two other pilots later stated that the strip surface was affected by soft sand, and only had a usable length of about 500 m. The aircraft performance charts indicated that a takeoff roll of approximately 600 m was required under the prevailing conditions. It is considered likely that the pilot attempted to fly the aircraft off the ground prematurely. As a result, the aircraft climb performance was adversely affected by induced drag.