Incident Summary
On 12 March 2001, at 0414Z, a South African Airways Boeing 747-400, registration ZS-SAZ, was operating an international scheduled flight from Johannesburg International Airport to Heathrow International Airport. During the flight, the cockpit crew received a 'FUEL IMBALANCE' EICAS (Crew Alert) Status message on number 4 engine. The crew subsequently shut down the engine and diverted the aircraft to Barcelona Airport, where it landed safely without further incident. There were no injuries or fatalities among the 3 crew, 15 cabin crew, and 323 passengers on board.
Flight Details
The aircraft, a Boeing B747-400, was operating a scheduled international passenger flight. The flight had originated from Johannesburg International Airport and was en route to Heathrow International Airport when the event occurred. The aircraft diverted to Barcelona Airport as a precautionary measure following the engine shutdown.
Sequence of Events
According to the incident report, the first indication of a problem was the appearance of the 'FUEL IMBALANCE' EICAS message on number 4 engine. In response, the cockpit crew shut down the engine. The aircraft then diverted to Barcelona Airport and landed safely. No further incidents were reported during the landing.
Probable Cause
An inspection by a South African Airways ground engineer revealed that the fuel line between the fuel filter and the engine driven fuel pump on number 4 engine was chafed through, causing an excessive fuel leakage. The fuel line was replaced, and no further leaks were found. Additionally, a one-time inspection was carried out on similar fuel lines on other South African Airways aircraft, and securing clips were replaced as required. Service Bulletin SB No 73-9841 has been issued for replacement of the subject securing clips with a more robust part, which has been retrofitted on all Rolls Royce engines operated by South African Airways.