2003 East Timor air crash

The East Timor air crash occurred on 31 January 2003. In the accident, an Ilyushin Il-76TD of the Laotian Euro Asia Aviation, which had taken off from Macau Airport, crashed on final approach to Baucau Airport. All six occupants were killed in the accident, and the aircraft was completely destroyed.

Accident sequence

When the aircraft was 300 kilometres from Baucau, the captain instructed the first officer to make contact with Baucau air traffic management. Despite 25 attempts made by the first officer over the following 23 minutes, he was unable to reach air traffic management. The navigator then radioed the Baucau control tower. An air traffic controller who was present on site but was not on duty informed the pilots that Baucau air traffic management was not available that day and that the aircraft's pilots should decide at their own discretion whether to land the aircraft at the airport. The navigator acknowledged receipt of the radio message but did not enquire about the weather conditions at Baucau Airport. The captain then diverted the aircraft from the prescribed route towards the Baucau non-directional beacon and let it descend below the minimum altitude specified for a distance of 10 nautical miles from the airport. He continued the descent with the intention of carrying out a non-precision approach to runway 1 at the lowest safe altitude. None of the other crew members commented on the captain's descent below the safe altitudes.

As the aircraft approached Baucau, the pilots decided first to overfly the airport. During the overflight they found that the runway was not where they had expected it to be. The accident investigators later determined that this was due to the fact that the crew had not used the Baucau non-directional beacon as a reference point during the approach. Instead, they were said to have used selected data from the instrument approach charts in order to carry out an arbitrary non-precision approach with the aid of GPS. This was an impermissible procedure. Furthermore, the pilots were misled by erroneous data on their Jeppesen charts.

The pilot in command broke off the landing approach and the flight navigator stated that he would make a 4 km correction in order to position the aircraft for a second landing approach where, in his opinion, the runway lay. By applying the 4 km correction, the flight navigator provided the pilot in command with inaccurate data, which resulted in the aircraft being repositioned towards a point about 1.65 km (0.88 NM) north-west of the actual position of the runway 14 threshold. This incorrect data considerably increased the hazards of the user-defined approach procedure, and the risk of a controlled flight into terrain in this phase of the flight increased considerably. When the aircraft was aligned with the final approach course during the second landing approach, the flight navigator stated that, based on his assumption about the location of the runway 14 threshold, the aircraft was well high on the approach profile. The pilot in command increased the aircraft's rate of descent to about 18 metres per second (3,543 fpm) and said "Increased" ("Erhöht").

None of the other crew members commented on the high rate of descent or drew the pilot in command's attention to the fact that the approach was unstable at this point.

The flight engineer mistakenly interpreted the pilot's ambiguous statement as an instruction to him to increase engine thrust, and he moved the thrust levers forward. It took about two seconds for the pilot in command to notice that engine thrust had been increased, and he reacted with the call "No, I increased the vertical speed" and reduced engine thrust. The flight engineer's action to increase engine thrust was a significant distraction for the pilot in command in this phase of the flight and probably diverted his attention from the primary task of flying the aircraft to restoring the thrust to the correct setting.

At roughly the same time, the aircraft descended through 162 metres, which corresponded to the published minimum descent altitude for a straight-in landing on the NDB approach to runway 14. Neither the pilot in command nor the co-pilot appeared to notice that the aircraft had descended below the minimum descent altitude, probably because both were distracted by the flight engineer's erroneous action.

The high rate of descent continued uncontrolled until slightly less than two seconds before impact. It is likely that the pilot in command and the co-pilot were not aware of the high rate of descent, since neither of them was monitoring the flight instruments, …