Background
On November 19, a cargo aircraft departed Ostend, Belgium, for Lubumbashi, Democratic Republic of Congo, carrying one passenger, five crew members, and two machines, with a total weight of 20.2 tons. Intermediate stops were scheduled in Algiers, Tamanrasset, N’Djamena, and Kisangani.
Sequence of Events
After a fuel stop in Tamanrasset, the crew flew to Kano instead of the planned N'Djamena. The captain later stated that had Kisangani been identified on radar, he would not have initiated descent 38 nautical miles southeast of the city and then continued southwest for 140 nautical miles. Due to fuel exhaustion, the airplane descended, collided with trees, and crashed in a dense wooded area near the village of Okasa, approximately 205 km southwest of Kisangani. The aircraft maintenance engineer survived; five other occupants were killed.
Operational Issues
The flight departed Ostend before overflight clearances and landing permits had been obtained. The captain believed authorizations had been received after speaking to the London representative. The carrier had no effective dispatch or flight watch system for overseas cargo operations.
The crew proceeded directly from Tamanrasset to Kano rather than following the planned routing. To justify landing at Kano, they declared a false fuel emergency. At Kano, the crew had insufficient time to fully plan the leg to Kisangani, considering factors affecting flight safety.
The aircraft did not carry enough fuel to comply with minimum alternate requirements. The selected alternate, Bunia, was not suitable. The route depended on enroute radio aids that were published as unlikely to be available—information available to the crew during planning. There was no evidence that the crew knew the KGI VOR and KW NDB at Kisangani would be off the air.
The flight plan was not passed to Kisangani; the flight was not expected on the morning of the accident. Prior permission to use Kisangani was not requested nor received on the night of the accident. The crew did not use radar for navigation during the last leg.
Navigation and Communication Failures
The crew was misled by a bearing indication from the LU NDB at Luanda, whose frequency nearly coincided with the KW NDB at Kisangani. This led them to descend to low altitude and continue generally southwest for the remainder of the flight. Weather during the last hour would have been suitable for celestial navigation, but the aircraft carried no navigator, VLF, or INS navigation systems.
The aircraft was within reception range of VHF, VOR, and NDB facilities at Kisangani for 53 minutes between 0224Z and 0317Z on the morning of the accident. The crew attempted unsuccessfully to contact Kisangani Tower on 118.1 MHz while in range. Another aircraft also failed to make contact. Both aircraft had functional VHF transceivers. The crew also unsuccessfully attempted to receive signals from KGI VOR, KE NDB, and KGI NDB; C-FPWX had functional ADF receivers.
The VHF receiver (118.1 MHz) and HF/CW receiver at Kisangani were either unserviceable or unmanned during the 6-hour-40-minute period between 2255Z on November 20 and 0535Z on November 21. None of the navigational radio aids at Kisangani were functioning on the morning of the accident.
The crew did not make full use of available HF/SSB facilities in an emergency situation. They delayed declaring an emergency unnecessarily. The aircraft was beyond VHF reception range of Kisangani during all VHF emergency calls. They did not manually activate the ELT or select the emergency transponder code.
Air Traffic Services
No air traffic services (control, flight information, or alerting) were provided by Zaire ATS authorities due to inadequate communications facilities. Alerting service began at 0440Z on November 21, 2 hours 52 minutes after entering the uncertainty phase—20 minutes after the aircraft had crashed. The alerting service did not conform to ICAO Annex 11 standards.
The flight plan and ETA were not forwarded to Kisangani ATS due to lack of adequate communication between Kinshasa and Kisangani tower. Navigation aids (GEM NDB, LIS NDB) along the last 439 NM of the planned route from Libenge to Kisangani were published as not available during the flight time. Use of Kisangani and Bunia aerodromes was restricted to VFR only. Communications with radio operators at significant points along the route in Zaire were published as not available at night.
Crew and Company Practices
The aircraft departed Kano approximately 6,600 lbs over maximum takeoff weight. Company representatives scheduled cargo flight crews to exceed flight duty time limitations on charter operations out of Stansted. The captain knowingly exceeded duty time limitations on the accident flight and on prior occasions. Crew duty time on the accident flight was at least 34 hours, probably 42 hours. Evidence of crew fatigue was noted 14 hours and again 2 hours before the accident.
The carrier’s marketing and sales literature overstated the aircraft’s payload capability. Marketing and sales managers, lacking operational expertise, oversold the aircraft for the stage lengths involved. Hercules captains knowingly exceeded MTOW limitations and flew with insufficient fuel for standoff and alternate requirements. Direct and indirect pressure was applied to crews to exceed limitations and take off without sufficient fuel.