What happened
On May 16, 2018, a scheduled commercial flight, operating as EXY1123, departed O.R. Tambo International Airport (FAOR) bound for Mafikeng International Airport (FAMM). While the Bombardier/Canadair Regional Jet CL-6002B19, registration ZS-NMI, was climbing through 8,000 feet, the aircraft experienced a sudden leftward yaw. The flight crew identified an engine flame-out in the number 1 engine.
Following the incident, the crew issued a PAN-PAN call and requested routing to the MEV VOR to execute emergency procedures from the Quick Reference Handbook (QRH). The aircraft successfully returned to O.R. Tambo International Airport and performed a single-engine landing on runway 21L. There were no injuries among the 19 passengers and 4 crew members, and the aircraft sustained no damage.
The investigation
An investigation by the SACAA AIID focused on the mechanical state of the engine and the maintenance history of the components. Upon inspection at the maintenance hangar, investigators found no external damage to the engine. However, a detailed examination of the fuel management system revealed significant issues.
Technicians discovered excessive wear on the drive shaft connecting the fuel pump to the fuel management unit (FMU). Specifically, the gear train within the FMU showed evidence of wear that caused the drive gear to slip during operation. This slippage interrupted the fuel supply, directly causing the engine shutdown.