Come fly with me
We are accustomed to thinking of some industries as ‘class leaders’ when it comes to Human Factors. Probably near the top of that list we’d put the aerospace industry, particularly with reference to the design of flight decks and associated instrumentation. Sometimes however things don’t go quite as well as we’d like.
The common perception of the recent emergency landing of a Qantas Airbus A-380 at Singapore after the catastrophic failure of one of its engines was of a well handled emergency with a relative lack of drama.
The reality, as outlined in the initial report, shines a somewhat different light on how close this flight came to disaster. As well as the damage to the engine, there was considerable additional damage to the fuel systems and to the aircraft wiring. Take a look at this.
However, it’s the human response to the engine failure and the systems that support the crew that’s of interest to us.
There’s lots of interesting titbits from a human factors perspective in the report, such as the fact that there was no feedback to confirm the action when the crew discharged the engine fire extinguisher bottle. Faced with the lack of expected feedback, they assumed that the discharge had failed and discharged the second bottle. Expectations from previous systems and experience are powerful things.
Also, the passengers had a better and earlier view (via the in flight entertainment system) of the fuel loss from the wing than the crew did. Maybe that camera view should be available to the flight deck as well.
But the most startling element of the report for me, from a Human Factors perspective is the role of the alarm and message system. The Airbus A-380 has a sophisticated aircraft monitoring system (Electronic Centralised Aircraft Monitor (ECAM)) which provides status information to the flight deck. This is the system that alerts the flight crew to specific problems. For each message there is a response. What’s fascinating is that there were so many messages that it took the crew 50 minutes to scroll through them and respond before they had the confidence to land the plane. During this period they circled over the ocean in a holding pattern using the autopilot.
While they were managing the flood of alarms and messages they were silencing the flight deck warning horn, which seems to have been sounding repeatedly. This is something we all recognise from alarm floods in control rooms. The constant alarm tone interferes with verbal reasoning tasks and at this point is serving no useful purpose; in fact it’s interfering to a large extent with the management of the problem.
Meanwhile, back in the main cabin, the senior cabin crew member was attempting to contact the flight deck using the emergency contact selection on the aircraft communication system. This emergency call sounds the……flight deck warning horn, the very alarm that was been constantly silenced on the flight deck. A safety-critical communication path was cut off during the event. I wonder whether the cabin crew are ever included in simulator pilot or crew training?
When you read the report, it’s clear that the crew did a fantastic job of managing and recovering a potentially devastating incident and they deserve all the credit for saving the lives of all on board. There are however some very big human factors lessons that need to be addressed regarding alarms, messages and procedures in modern highly automated cockpits.
The interim report is available here and it makes fascinating reading (but probably not just before flying off on that vacation or business trip).
http://www.atsb.gov.au/media/2888854/ao-2010-089%20preliminary%20report.pdf#page=0
There’s also an article at the link below that raises concerns about crew competence in increasingly complex flight decks. It doesn’t relate directly to the Airbus A-380 incident, but it makes interesting reading.
The presence and scope of automation in control rooms as well as flight decks radically changes the competence requirements of operators/crew as well as the potential demands that are placed on them in the event of an emergency. We need to make sure that we fully consider these factors when exposing people to highly automated environments.
As always, what do you think? Are there parallels with your control room or facility?
Photos are courtesy of the Australian Transport Safety Bureau