The pilot of VH-BLX had planned to fly from Tully direct to Cooktown via Cairns. However, due to unsuitable inland weather the pilot changed the planned route before DEPARTURE to fly coastal at 1000 feet. The pilot reported DEPARTURE from abeam Dunk Island. He was later cleared to transit the Cairns control zone at 1000 feet, tracking initially from False Cape, (nine kilometres east of the aerodrome), to the control tower. As the aircraft was approaching the control tower from the east at 1000 feet, a Boeing 737 aircraft VH-CZL was approaching from the south at 2000 feet. VH-CZL overflew the control tower before being instructed to turn right and then make a left circuit for runway 15. The pilot of VH-BLX reported sighting the jet, and was instructed to pass behind it. VH-BLX was then instructed to turn further right, to ensure that the flight path of VH-BLX would be to the east of the jet's flight path. After the pilot of VH-CZL had been given a landing clearance VH-BLX was instructed to turn left and was given the choice to track coastal or direct to Cooktown. The pilot was asked to report passing Double Island, 17 kilometres north-west of the airport. This was acknowledged by the pilot. The aircraft was last seen from the control tower tracking west towards Yorkeys Knob, eight kilometres to the north. No further transmissions were heard from VH-BLX, and an extensive search failed to locate the aircraft. The pilots body was found three days later in the entrance to Cairns harbour. An oil slick was seen south of Double Island on the same day but it could not be confirmed that it was from the missing aircraft. A trawler has since reported netting an object south of Double Island which may have been the aircraft wreckage. The object was lost from the nets before it could be identified. Aircraft components have since been found in trawler nets at the same position, including the propeller and a section of wing structure. The structure shows evidence of being subjected to extreme impact forces. A search of the location has been conducted by Water Police without any success. This accident was not the subject of an on-scene investigation.