What happened
On 14 April 2022, an Airbus A330-300, registration ZS-SXM, operated by South African Airways, underwent a protracted refueling process at Kotoka International Airport in Accra. During the use of a PUMA Energy refueller truck, the aircraft experienced several automatic interruptions. To troubleshoot these stops, an engineer performed a sump drain which revealed the presence of water in the wing fuel tanks. Although the water was drained and refueling was completed using a hydrant dispenser, the flight departed with a delay.
Approximately five hours into the flight, while cruising at FL410, the flight deck crew received an ECAM message indicating low pressure in the right-wing fuel pumps. This necessitated a descent to FL190 to utilize gravity fuel feed procedures. Shortly thereafter, at 2018 UTC, the crew received an ECAM message indicating an engine stall on Engine #2. Despite attempts to increase thrust, the crew received further stall indications. The aircraft continued to Johannesburg and landed safely.
The investigation
The investigation examined the refueling sequence in Accra, the presence of water in the fuel tanks, and the subsequent in-flight engine performance. Investigators analyzed maintenance records, fuel delivery tickets, and communications between the airline and ground service providers. The inquiry also reviewed the possibility of microbiological contamination versus high concentrations of water as the cause for the engine stall and fuel pump issues.