During the take-off from Sydney earlier in the day, the captain noticed some slight surging of the engines and had difficulty synchronizing them during the climb. Surging was again experienced during take-off at Nyngan, the intermediate stop, but this disappeared on the first reduction from take-off power. The flight from Nyngan to Bourke was otherwise uneventful, the aircraft arriving there at 13:21 hours; it was then loaded and refuelled for the return flight. At about 13:37 hours the aircraft was taxied to the displaced threshold marks towards the south-west end of runway 5 and a take-off was immediately commenced into the north-east. The aircraft became airborne after an apparently normal take-off run, but shortly after leaving the ground the starboard engine backfired and the first officer noticed a fluctuation of revolutions and manifold pressure and rough running of this engine. The captain, although not aware of these latter symptoms, heard the backfiring and felt an uneven load on the rudder pedals; from these symptoms he concluded that the engine had failed and as a result feathered the starboard propeller. A few seconds later the first officer saw the starboard propeller had not stopped but was rotating at an engine speed of some 600 to 700 r.p.m. and he could only distinguish individual blades with difficulty. He concluded that the propeller had not feathered and so informed the captain, who instructed him to press the feather button again. The button was pressed several times but each time immediately returned to the normal position. On the captain’s instructions the first officer then held the button in for some two or three seconds but, on releasing it, the button again immediately returned to the normal position. The first officer was unable to detect any change in the propeller’s condition and it continued to rotate at a constant speed accompanied by considerable vibration of the engine. At about this time the captain decided to abandon the take-off. Eyewitnesses state that the aircraft did not climb much after take-off before levelling out, ú and thereafter it flew just above the trees for about a mile before descending from sight. At this time the starboard propeller was rotating slowly, and was seen to stop just before the aircraft descended from their view. The landing was effected in an area almost clear of trees but near the point of touchdown the starboard wing tip was sheared off on a small tree. The aircraft maintained its direction for 380 feet before colliding with a stump which caused it to slew violently to the right and turn through about 180ø. It came to rest 555 feet from the first point of contact. The starboard propeller was torn from the engine just after ground contact and came to rest 60 feet short of the main wreckage. The wreckage was located 3,200 yards from the end of the runway and 8 degrees to the right of its centreline. The surrounding terrain is flat and sparsely covered with trees of an average height of 30 feet. PROBABLE CAUSE: “The pilot, having failed to adopt the correct technique for asymmetric flight following failure of the starboard engine on takeoff, abandoned the takeoff in the belief that it was not possible to remain airborne. In his handling of the situation following failure of the starboard engine the pilot was severely handicapped by his inadequate knowledge of the performance of and the technique for flying the DC-3 type with one engine inoperative.”