The helicopter was engaged on local joy flights, each flight being of about 7 minutes duration. After completing several flights the pilot said he dipped the fuel tanks and determined the remaining fuel quantity to be 70 litres. At the completion of two more flights, the pilot decided to proceed to Albion Park aerodrome to refuel. As the helicopter passed through an altitude of 700 feet on descent to Albion Park the engine stopped. The pilot gave a Mayday call and carried out a trouble check but was unable to identify the reason for the engine failure. An autorotative landing was subsequently conducted onto swampy grasslands near the northern shore of Lake Illawarra. It was reported that the helicopter touched down on the heels of its skids and pitched forward, decelerating rapidly due to long grass and soft surface conditions. As the helicopter pitched forward the main rotor blades severed the tail boom. A subsequent inspection of the engine failed to reveal the reason for the engine failure.