About 20 minutes after take-off on the return leg of a charter flight and while cruising at 4500 feet amsl, the right engine suddenly lost all power. The pilot reported that he was unable to restore power, and he elected to land at a nearby ALA. From the downwind position a continuous left turn was flown to align the aircraft with the strip. On short final approach the left engine also lost power and the aircraft touched down short of the strip boundary. It ran through two fences and the nosegear collapsed after striking a dirt bank. The flight was the first one in the aircraft type for the pilot in an unsupervised capacity. Investigations carried out at the accident site revealed that there was adequate fuel remaining in the main tanks, although the auxiliary tanks were virtually empty. Both engines were started and ran normally, and no fault was subsequently found with them that might have explained the power losses. The pilot did not have a detailed knowledge of the fuel system, and it was considered likely that he had mis-managed the system.
