What happened
A twin-engine aircraft was performing a specialized flight from Dodoma to Dar es-Salaam, transporting nine members of the United Nations Organization who were participating in a humanitarian operation within Tanzania. While the aircraft was cruising at an altitude of 4,000 feet, it encountered severe weather characterized by thunderstorm activity.
As the plane entered the cloud layer, the pilot experienced spatial disorientation, leading to a loss of control over the aircraft. During the subsequent uncontrolled descent, the airplane reached speeds that caused an overload failure, resulting in the partial disintegration of the airframe. The wreckage eventually crashed into a pasture. There were 10 fatalities among the occupants.
Findings
The investigation concluded that the primary cause of the accident was midair disintegration due to structural overload, as the aircraft's diving speed exceeded its design limits. This intense force caused the fuselage and parts of the empennage to separate from the rest of the structure; during this process, the occupants were ejected from the cabin.
Several contributing factors were identified in the accident:
- The pilot experienced spatial disorientation while flying through clouds.
- The aircraft's onboard weather radar was not functional at the time of the incident.
- An appropriate penetration speed had not been established before entering the thunderstorm area.
- The aircraft was operating under an overloaded condition.