At 1911 hours the pilot made a routine radio transmission stating that the aircraft was 20 miles (37 kilometres) north-west of Roma inbound, and leaving 4000 feet on descent. He then spoke to the company at Roma on the company VHF frequency. The pilot did not respond to a traffic advisory call from Brisbane Flight Service at 1914 hours, and did not report his arrival at 1917 hours, the estimated time of arrival. Later, when the aircraft could not be located on the ground at Roma aerodrome, an aircraft which had previously departed Roma was diverted to search along the inbound track of the missing aircraft. An Emergency Locator Beacon (ELB) signal was later detected by a searching Army helicopter 19 kilometres west-north-west of Roma, and the wreckage was located at 0145 hours. The aircraft had flown into trees whilst in a shallow descent. Both engines were operating and the wings were level at impact. The weather was fine and the sky was clear but it was a very dark night with no discernible horizon. There were no defects found with the aircraft that may have contributed to the development of the accident. The Minimum Safe Altitude for aircraft operating visually at night in the Roma area is 3000 feet above mean sea level (amsl). A visual descent may only be continued below 3000 feet at Roma when the aerodrome is in sight, and the aircraft is within 3 nautical miles. The accident site is approximately 1050 feet amsl. There was no evidence that the pilot was incapacitated, and the reason the aircraft descended below Minimum Safe Altitude was not determined.