The pilot reported that the aircraft engine lost power when he made a power adjustment whilst on final approach. The propeller feathered and the aircraft landed short of the runway on unprepared ground, incurring substantial damage. The aircraft was being used for parachute drops from 14,000ft. When the last parachutist left the aircraft, the pilot would place the aircraft in a steep spiralling descent. During this type of descent, the pilot was known to exceed the 60 degree angle of bank limits for the aircraft. Low fuel states were reported as being used for the paradrops. It is probable that the fuel flow from the wing cells to the collector tank (18 litre capacity) was interrupted during the descent and air entered the system. The fuel pump was not designed to operate in other than a full collector tank. As a result it is likely that the fuel flow to the engine was interrupted, resulting in engine flame out.