Synopsis
On 8 December 1976, at 0955 GMT, a Cessna 402B aircraft, registration 5Y-WAW, crashed into Lake Victoria approximately 5.5 nautical miles west-northwest of Mwanza, Tanzania. The aircraft was operating a charter flight from Mwanza to Bukoba on behalf of Caspair Ltd. The pilot and nine passengers sustained fatal injuries. The wreckage sank in about 109 feet of water and was not recovered despite salvage attempts.
History of the Flight
The aircraft departed from Mwanza Airport Runway 30 on a direct course to Bukoba. Normal take-off clearance was given, and no further communication was received from the pilot. Weather at Mwanza Airport was clear, but a severe thunderstorm was reported over the lake approximately four to five miles offshore. When the aircraft failed to arrive at Bukoba, search and rescue operations were initiated. Pieces of wreckage and an oil slick were sighted about five miles offshore approximately 24 hours after departure.
Injuries to Persons
The accident resulted in fatal injuries to all 10 occupants: one crew member and nine passengers. No survivors were found.
Damage to Aircraft
The aircraft was destroyed. Recovered floating wreckage included the nose cowl, port and starboard top engine cowlings, small pieces of side cowling, an oxygen container, and one passenger seat. The main wreckage remained submerged at a depth of approximately 109 feet, located on the 310 radial of Mwanza NDB, about 5.5 nautical miles from shore. Salvage efforts by the Tanzanian government were unsuccessful due to depth, muddy bottom, and lack of equipment.
Personnel Information
The pilot, aged 44, held a valid Commercial Pilot's Licence and instrument rating, with a total flying experience of 6,346 hours. His medical certificate was valid. No issues were noted with his qualifications.
Aircraft Information
The aircraft was a Cessna 402B twin-engine land plane, manufactured in February 1976, powered by two Continental TSIO-520 engines. It had a valid Certificate of Airworthiness and a valid maintenance certificate. Total flying time since new was approximately 200 hours. The aircraft's weight and balance were within limits at takeoff.
Meteorological Information
At the time of the accident, the Mwanza area weather at 0900 GMT reported surface wind 180/05 knots, visibility 40 km, temperature 27.5°C, QNH 1016 mb, with cumulonimbus clouds. Witnesses confirmed a severe thunderstorm over the lake about four to five miles offshore, with heavy rain and turbulence. The accident occurred in daylight.
Wreckage and Salvage
Floating wreckage was positively identified as from 5Y-WAW. Salvage operations attempted 3 to 4 days after the accident were called off after five days due to depth, muddy bottom, and poor visibility. One passenger's body was recovered 14 days later, still strapped to a seat that had floated to the shore.
Medical and Pathological Information
The pilot's last medical examination was satisfactory. The recovered body was in an advanced state of decomposition, providing little useful pathological information.
Analysis
The investigation considered witness reports of a severe storm on the flight path. Evidence from floating wreckage indicated the aircraft struck the water in a nearly level or slightly nose-down attitude. Abrasion marks on the nose cowl and torn engine cowlings were consistent with impact at a shallow angle. The pilot, experienced on the route, may have attempted to fly beneath the storm, losing visual reference or encountering turbulence. However, without the main wreckage, no final conclusions could be drawn.
Conclusions and Cause
The accident appears to have been caused by the aircraft striking the surface of the water in either a normal flying or slightly nose-down attitude. The exact reason for this could not be established as the main wreckage was not recovered.