Accident Overview
An uneventful flight from Cairo culminated in a descent toward Bunia Airport. However, poor visibility due to a low ceiling hampered the approach. During the final approach, the four-engine airplane impacted the slope of Bogoro Peak, located approximately 8 kilometers short of the runway. The wreckage was discovered 100 meters below the summit. All 35 occupants were killed.
Official Findings
The investigation determined that the accident occurred because the pilot, the captain, executed a descent while the height of the cloud base (ceiling) was below the minimum required by the Administration and the Operator. Key findings include:
- The weather had been deteriorating rapidly. The ceiling dropped from 16,000 feet to 700 feet in two hours and 30 minutes. At the time of the accident, the ceiling was between 700 and 800 feet, below the prescribed minima.
- The captain should have decided to divert when conditions fell below minima.
- The captain should have noticed the abnormally long time between exiting the procedural turn and passing the locator. The distance of 8 kilometers, at an approach speed of 220 km/h (120 knots), would normally take no more than 2 minutes and 30 seconds.
- A combination of unforeseen circumstances made the pilot’s carelessness fatal. Had the VHF not failed at the start of the procedure, the airfield operator could have warned the pilot that the beacon was out of service, possibly preventing the continuation of the approach.
- The operator at the Stanleyville Protection Office was cited for serious negligence in failing to relay the latest weather report from Bunia (at 7:50 a.m.: 8/8 stratus at 200 meters). The operator was not required to determine the usefulness of the information, but the communication was of great importance during the procedure.
- It was noted that Bunia, a regular stopover for DC-3s, DC-4s, and CV-440s, was not a controlled airport.
Probable Cause
According to the official investigation, the probable cause is that the pilot, the captain, carried out a descent while the height of cloud base (ceiling) was below the minimum required by the Administration and the Operator.