Accident Overview
The aircraft, registered as N204C, departed Tokyo-Narita Airport en route to Jakarta with a planned fuel stop at Kota Kinabalu Airport. On board were nine passengers and three crew members, including four corporate members of the Conoco Group, which had leased the aircraft from DuPont de Nemours.
Approach to Kota Kinabalu
The flight to Kota Kinabalu was uneventful. After being cleared to 10,000 feet and then to 5,000 feet, air traffic control (ATC) instructed the crew to follow a southerly route (heading 180°). The crew was told that after passing the VJN VOR at 4,000 feet, they could expect clearance for an approach to runway 02. While descending to 4,000 feet, the aircraft disappeared from radar screens after striking the slope of a mountain in the Crocker Mountain Range, approximately 9 km northwest of Keningau and 57 km south of Kota Kinabalu Airport.
Wreckage and Occupants
The aircraft was destroyed upon impact, and all 12 occupants were killed.
Official Findings and Probable Cause
The investigation determined that the accident was the consequence of a series of errors and omissions by the flying crew, resulting in a controlled flight into terrain. The following contributing factors were identified:
- The pilots did not reduce the aircraft's speed to approach speed as directed by ATC (Event69). This error caused the aircraft to arrive over the VJN VOR/DME approximately 15 minutes earlier than expected, with an average ground speed of 400 knots inbound to the VOR/DME.
- The pilots did not follow the published descent profile for their arrival sector. Adhering to the profile would have placed the aircraft at 4,000 feet over the VJN VOR/DME and in position for the initial approach segment of a VOR/DME approach procedure.
- The cockpit voice recorder (CVR) indicated the pilots did not consider any published approach other than the ILS approach, yet they did not specifically request the ILS.
- Radiotelephone communications by the copilot, Johnston, were sloppy and non-compliant with ICAO standards. He indicated understanding of an ATC directive to descend over the VJN VOR/DME to 9,500 feet by repeating part of the directive, suggesting compliance.
- The pilots did not seek clarification on the ATC directive to “descend south of the airfield” and to maintain heading 180°. A proposed ground track by Frank Petersen showing the aircraft flying outbound from VJN VOR/DME on the 180° radial was deemed incorrect, as it would place the aircraft 3 nm east of the crash site at the time of the right turn, a distance that could not have been covered in 25 seconds (at 230 knots, it would take over 46 seconds). Moreover, that track would have resulted in an earlier impact along the 180° radial.
- Cockpit conversation at Event179 revealed that both pilots observed high terrain 52 seconds before impact, when the aircraft was less than 1 nm from eye-level hills at 4,000 feet and less than 1.7 nm from a 4,875-foot peak. The pilots should have realized they were violating IFR approach procedures, but they made no comment to ATC about the terrain or cloud conditions.