Egyptair MS804: significance of ACARS messages clarified

Airbus is not, at present, able to give specific advice to A320 operators based on information available from the Egyptair MS804 investigation, according to a report by Flightglobal senior journalist David Kaminski-Morrow.

Data transmitted by the aircraft’s ACARS messaging unit to the Egyptair operations centre is insufficient to point to a cause, he reports, explaining: “Airbus has already informed operators, via two accident information bulletins, that the available data is limited and that the analysis of the transmissions does not contain enough data to determine the accident sequence, Flightglobal has established.”

The Flightglobal report continues: “With the inquiry unable to conclude whether a technical flaw contributed to the crash, the airframer has been unable to provide any immediate advisory to operators.

“Although seven ACARS maintenance messages transmitted in the space of 3min – between 02:26 and 02:29 Egyptian time – hint at the possibility of smoke and heat in the forward fuselage, there is no confirmation that the time-stamp of the messages correlates with the order of the trigger event and no clear indication of the precise time interval between them.”

The unknown factor is the “trigger event” referred to. The ACARS messages (see earlier blog entries) and the circumstances of the crew’s loss of control over the aircraft do not provide specific evidence to indicate either sabotage or a fault as the trigger event.  But whichever it was, it appears to have generated fire that caused progressive electrical failures, and the crew’s loss of control over the aircraft ensued soon after that.

Floating wreckage and body parts recovered from the water where the aircraft crashed into the Mediterranean Sea north of Alexandria, Egypt, so far provide no clue as to whether sabotage or another cause brought the aircraft down. And the search coordinators have released no information about how widely the wreckage field is spread. This can be an indicator of whether the aircraft came down in one piece or had broken up in the sky, but after time the clues can be lost because the floating wreckage can be spread by sea currents and wind.

All this makes the recovery of the main wreckage and the flight data and cockpit voice recorders from the sea bed vital for the understanding of what caused the loss.

 

MS804; did the crew report smoke to Egyptian ATC?

French television news channel M6 reports that Egyptian air traffic control sources have told them the crew of Egyptair flight MS804 radioed to Cairo control that there was smoke in the aircraft and that the crew intended to make a rapid descent.

There was indeed a rapid descent, but one over which the crew lost control for reasons that are still being investigated (see previous blog entry).

If the M6 report is confirmed as accurate, this would contradict official statements by the Egyptian authorities that there had been no emergency call or reports to ATC of trouble in the aircraft.

All communications about this tragic event are sensitive because the friends and relatives of the passengers and crew, despite their distress, are hungry for information about what happened to cause their death.

So if the Egyptian authorities were indeed withholding simple but established facts about the flight, such a policy of silence needs to be reviewed.

It’s already known that Egyptair held ACARS data (see previous blog entry) about MS804’s technical troubles just before the aircraft was lost, and the authorities did not release these facts, although they were leaked two days after the accident and confirmed by the French accident investigator BEA as accurate.

In contrast, following the loss of Air France flight 447 over the South Atlantic in 2009, Air France and the investigator BEA quickly released information from ACARS about an airspeed-reading anomaly that occurred at the beginning of the sequence of events that led to the loss of the aircraft, although it was not known until much later what part that anomaly played in the crash.

About 30 years ago there was a universal policy by air accident investigators all over the world to tell the press and people that they should wait for the final report, and no facts would be released until then, because they might be understood out of context.

But for the last 15 years or so it has become practice in most advanced economies to release significant facts when they have been established, even if the full context is not yet clear, and to release interim reports when a basic picture of the situation – or a part of it – becomes known. Usually interim reports are issued with caveats about what is not yet known or understood.

The latter policy treats the friends and relatives of accident casualties with respect, and credits the general public with enough intelligence to interpret incomplete but factual information as what it is – incomplete information.

Not only has policy about the release of information changed in these countries, but the communications environment has been transformed by the internet, 24h news coverage, and social media.

That change in communications has radically altered people’s expectations about being able to access information quickly. So if – during investigation of an issue of public interest – it becomes clear that the authorities have been withholding information, or simply not processing it efficiently because of bad internal communication systems, it tends to engender a failure of public trust in those authorities.

It is far better for the authorities themselves, let alone for those whom they serve, to release established facts officially as soon as possible rather than to see them – inevitably in today’s communications environment – leak out unofficially.