Australian authorities have arrived in San Francisco to investigate an incident involving a Qantas Airways Boeing 747-400 that experienced an uncontained engine failure during flight.

Two investigators from the Australian Transport Safety Bureau (ATSB) will remain in San Francisco over the next few days to examine the engine and components and work with Qantas to determine the cause of the failure, says the ATSB.

In the 30 August incident, engine number four of the Rolls-Royce RB211 powered 747 failed shortly after take-off from San Francisco airport for Sydney.

The failure was mechanical in nature and uncontained, and ejected material punctured a hole in the outboard engine and damaged the aircraft's leading edge flaps, says the ATSB.

The aircraft, registration VH-OJP, returned to San Francisco after the flight crew dumped fuel. No one was injured in the incident.

Australian authorities have classified the incident as serious.

Following investigations in San Francisco, the damaged engine will be sent to maintenance facilities in Hong Kong where it will be further examined by technical investigators from the ATSB, says the bureau.

Source: Air Transport Intelligence news