We’ve been studying Human Performance and Limitations (HPL)
this last week and a large part of HPL is given to look at previous accidents
to see what can be learnt and how aviation can be made safer. As I’m sure you are aware, there has been
some devastating news over the past few weeks with aviation disasters frequenting the headlines. My thoughts and prayers are with those
recently affected by these disasters, and for me it’s been a humbling reminder of the
responsibility that everyone in aviation carries to ensure these accidents don’t
happen again.
In the wake
of these tragedies there have been plenty of experts assuring us that flying is
still very much safe (for our exams we work on an fatal accident probability of
1: 1 000 000 per flight in the UK, and I’ve seen it quoted up to 1 flight in 3 million in The Guardian - compare that to a car accident rate of 1: 10 000). Although
aviation accidents are few they can in their nature be very shocking due to the numbers of people involved, and that’s why as a trainee it’s really
important to find what we can learn from previous mistakes.
These accidents are rarely due to a single cause, and Reason’s Swiss
Cheese Model illustrates this quite nicely – in itself, a hole in a Swiss
cheese is not an issue as there are many layers of defence (“cheese”) before a
total system failure. However, when a
series of holes (the failures) are lined up in each layer then there is a route
straight through to the eventual failure.
We’ve looked at many different accidents and in particular how the human
factors contributed to the overall loss of an aircraft. In most cases removing
one of many errors could have avoided the accident, and we are learning how to
recognise these opportunities to prevent accidents, as well as using resources
effectively (i.e. having good communication between crew) to ‘insert’ extra
slices of cheese to provide further defence of a situation developing.
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| Reason's Swiss Cheese Model where the failures line up through each layer of defence (wikipedia) |
Learning about this is only the tip of the
iceberg with regard to safety – it’s just an introduction really! Of course, for those of us that are watching the "Air Crash Investigation" for a particular accident it's very easy to say what should have been done from the comfort of our armchairs but in reality it is not that simple, although we are aiming to learn from it all the same. We are embarking on careers where safety is
above all, and we will be exposed to difficult scenarios in the simulator time
and again in order to allow us to recognise and prevent situations from
escalating. It’s this very training
which gives aviation a strong safety record, and we are now moulding our
attitudes to reflect this safety culture.
