The final report on the 2004 Flash Airlines Boeing 737-300 fatal accident published late last month concludes that the cause was uncertain, but it points to technical anomalies that might have started the accident sequence. This verdict of the Egyptian civil aviation authority investigation team, which led the probe, conflicts with analyses by the two other parties to the process.

The US National Transportation Safety Board (NTSB) and French accident investigator BEA – representing respectively the state of aircraft manufacture and the state from which the passengers originated – independently dismiss technical factors as causal and blame loss of control on the captain’s spatial disorientation.

A disagreement arose the last time the NTSB and Egyptian investigators worked together – on the investigation of the October 1999 Egyptair Boeing 767 crash into the sea off the US east coast.

That report was published in 2002, and the NTSB – the lead investigator – ruled out mechanical failure as a causal factor and blamed the pilot flying, while the Egyptian CAA cited the possibility of mechanical malfunction leading to human mistakes. An identical dispute occurred when Indonesian investigators reported on the December 1997 Silk Air 737-300 accident. Indonesia recorded an open verdict, but the NTSB insisted the cause was human factors.

In both the latter cases flightcrew actions were judged causal by the NTSB, with deliberate action by the pilot flying a potential explanation for the control inputs made. In the Silk Air case the cockit voice recorder and flight data recorder stopped operating shortly before the aircraft entered a steep dive.

In the Flash Airlines case, however, there is no suggestion that deliberate pilot action played any part.

Source: Flight International