Thursday, 24 January 2013


Hello everyone, sorry it's been a while but endless revision has been driving me round the bend and I haven't felt like I had much positive to say.

The phase one school finals are finally out the way and I managed a very respectable 97% average in the exams (thanks mainly to two very short, very easy comms papers). Perhaps once I have finally caught up on sleep and given my brain a rest I will be able to feel positive about that.

We now have a welcome week at home to prepare for the 'real' exams which start on 4th. The format and difficulty should be identical to the school finals so barring any nasty surprises I can't see me or any of my colleagues on the BA programme coming unstuck. We will then be more than half way through ground school and and after that... two weeks off! Happy days.

The subject of this post is gethomeitis (Get-Home-Itis). This is not as it sounds a painful disease of the big toe. It does not mean that I've been desperate to get home to my wife (though I have). It is a rather ugly aviation term meaning simply the tendency of pilots to want to complete the flight as planned and land at the destination no matter what.

Gethomeitis? In gliding, a low approach over unlandable
terrain might get you home, but would a landing in a field
five miles back have been the safer option?
Gethomeitis has been the cause of an awful lot of aviation accidents; not just gliders and private planes but airliners too. One study in France reckons that gethomeitis caused 42% of all fatal accidents to aircraft on visual flights between '91 and '96.

In 2001, a regional airliner Crossair 3597 crashed in Zurich killing 24 of the 28 people on board. The highly experienced Captain Lutz attempted to land in poor conditions on a runway that was not equipped with an instrument landing system, just as the airport was closing.

There is nothing intrinsically wrong with attempting an approach in touch-and-go conditions provided the correct procedures are followed. Lutz however put the plane into a fast, steep descent and — crucially — flew well below the minimum safe altitude for the approach without visual contact with the runway. He then claimed he could see the airport when he could not possibly have done and continued the approach. The relatively inexperienced first officer did not intervene, with the tragic result that the plane crashed into hills some miles short of the airport.

How could a highly trained and experienced airline captain to make a string of such poor judgements? To answer this, we need to look at some psychology.

It's quite fashionable among trainee pilots to treat the subject of Human Performance rather dismissively, and to be fair there is a lot of meaningless verbiage in the textbook. Or as my wife called it when helping me to revise, "mumbojumbo". She is a master of unintentional puns.

But buried in the management speak there are some gems, including this insight into human decision making (bear with me here).

It turns out that people are hopeless at assessing risk. Absolutely terrible. After all, would we spend £6 billion per year on gambling in UK if we weren't? Would we ever drink and drive? Would anyone smoke?

There are two major biases in the way people assess risk and benefits.

1. Given a choice between two positive outcomes, people will choose the one that is more certain. For example, if I offered you the choice of £10 cash now, no strings attached, or £100 in August 2014 "probably, if I remember", you'd no doubt take the tenner. I'm not known for my good memory, and it's very hard to turn down a dead-cert.

2. Given a choice between two negatives, people tend to avoid the more certain one. Gambling is the typical example; if you have lost money the temptation to up the stakes is incredibly strong, even though the chances of a big win are remote. When our outcomes are negative, suddenly we favour the long-shot.

And the closer we are to our goal, the more reluctant we are to give it up. There is even a name for this — the Concorde fallacy.

Despite endless problems, the British and French governments repeatedly ploughed incredible amounts of money into developing Concorde. Costs spiralled utterly out of control, but so much had already been invested that failure simply could not be countenanced. Eventually six times more than the original budget was spent. They did finally succeed in getting it into service, and it was an engineering marvel, but financially it was a disaster.

You've probably already realised that this phenomenon explains gethomeitis. In the position of Captain Lutz of Crossair flight 3597, you basically have two options:

1. Play it safe and divert to an alternative airport. This will really annoy the passengers, it will cost the company a lot of money in hotels, food, lost customers and another flight the next day, it will mess up all the rosters because the aircraft and crew are in the wrong place. In short, it is a pain in the arse for all concerned; a certain negative situation.

2. Continue and try to land in poor conditions. If successful, which is highly likely, none of the above will happen.

Of course there is the tiny risk of total disaster, but as we have seen people routinely underestimate this (or we probably wouldn't drive cars) and cling onto the much larger chances of avoiding the known problems of diverting.

Put this way, you can start to understand — though perhaps not forgive — his behaviour. On top of this, he apparently was right at the end of his maximum duty hours and therefore tired, and he wanted to go to his grand-daughter's birthday party the next day. These considerations should not be important but hey, we are all human.

So how can we avoid making similarly bad decisions, not just in flying, but in life generally?

The answer is to flip around the options to make them both positive. As we saw above, when options are positive, people tend to favour the dead-cert over the long-shot. We could rewrite Captain Lutz' options like this:

1. Avoid the certain inconvenience of diverting and all the associated hassle and costs by simply continuing on and hoping the landing goes well. Or

2. Avoid the slight possibility of total catastrophe, loss of the aircraft and multiple fatalities by diverting to a safer airport.

It's obvious, isn't it? Put that way, how could you not take the safe option?

Captain Lutz was probably going through his ground school training in about 1950, most likely in the military. I very much doubt that he had the benefit of modern psychology to assist his decision making. If he had, perhaps he would have looked at the situation differently, and him and 26 others would be alive today.

The modern airline pilot must continuously make decisions and judgement calls based on experience and knowledge, and despite their best efforts and training they are subject to the same human foibles as the rest of us. So this sort of knowledge is not incidental, it is absolutely central to the job. Human Performance is a compulsory part of our training for a reason — it may turn out to be the most important subject we will ever study.


  1. excellent post, from the master of mumbojumbo...your wife!

  2. Excellent looking fwd to your next post! FredM


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