Why Do Experienced Pilots Crash?- Prospect Theory and Soaring

How do most pilots crash in this sport? The overwhelming answer is the stall/spin on base to final. While quite a few of these accidents happen to inexperienced, sub 250-hour pilots, several 30-40 year veterans will crash each year from land-outs or final glides gone wrong. As a result, it is the decisions leading up to this point that are most fascinating when trying to understand judgment and risk assessment. John Cochrane has studied these subjects at length and detailed how some of the reasoning and psychology in You Will Be Tempted and Safer Finishes. I will build upon Cochrane’s reasoning to explain the psychology of why pilots can inexplicably take much greater risks than they would normally take.

Contrary to popular belief, people take biggest risks when they are confronted with losses rather than gains. While most of the risks that we discuss are of the “positive” kind, such as whether to gamble on flying an hour farther from home, 1000ft lower to find a better thermal, etc, these are not the sort of risks that result in bodily danger.  A pilot can fly a very thin tactical margin, which can be construed as an “aggressive” risk-taking strategy, but never risk hurting himself so long as he makes safe decisions prior to landing. On the other hand, a pilot who is consistently “conservative”, but will try to thermal at 300ft to avoid landing out will have gambled on his life much more than the “aggressive” pilot who drives around his glider at 100 knots down to 1000ft, hoping to hit a 7 knot thermal, but immediately quits once down to 800ft and executes a safe landing.

So this begs two questions:

1) Why are pilots willing to gamble so heavily, particularly in land-out situations?

2) Why is it so difficult to assess the risk?

To answer the first question, let’s first consider an adapted thought experiment conceived by psychologists Daniel Kahneman and Amos Tversky (Kahneman 281):

What do you pick for these following choices?

1) a) Accept a $400 gain or b) Take a 50% chance to gain $1000, 50% of losing nothing

2) a) Accept a $400 loss or b) Take a 50% chance to lose $1000, 50% of losing nothing

Most people would answer A and B respectively, albeit B and A are the more economically efficient choices. For the first scenario, the expected value of the gain of B is $500, which that the gamble over the long run has a payoff of $500. For the second scenario, the sure loss of $400 is hard to bear so most would take the gamble to avoid losing anything. However, economically speaking it’s a loser of a bet relative to option A, losing on average $100 more over the long run. However, A and B feel a lot better due to how people normally approach gains and losses. Specifically, that losses are much more painful and that people become more risk-seeking to avoid them.

Daniel Kahneman and Amos Tversky pioneered this economic concept in their “Prospect Theory”. The most important idea here is that losses are felt asymmetrically to gains. In finance, where it has been demonstrated that for most people it takes 2.5 dollars to emotionally compensate for a 1 dollar loss. There are plenty of anecdotes that further reinforce the point such as the folk expression not to,”Throw good money after bad.” Or “Sunk-cost fallacy.” Or the stories of bankers committing suicide during Black Tuesday of ’29 when they saw their net worth shrink. 

While loss aversion is easiest to test using money, it permeates all aspects of human nature, even soaring. If we are exposed to the possibility of a loss, we will do our absolute darndest to avoid it. Sports teams that are behind in the fourth quarter work harder than they did in the first quarter. And unfortunately, pilots who are looking at the possibility of unexpectedly landing in a field will do everything they can do avoid it, to the point that they may risk bodily harm to do so.

Why are pilots so averse to landing out? Many of the obvious reasons are the inconvenience of retrieve, dealing with the farmer, and expense. Some of the things that may be even more salient are the feeling of embarrassment and the thought that the pilot will “get in trouble”, especially if it was in a club glider. Lastly, if the possibility of landing out occurs in a contest, the pilot may also be considering all the effort, time, and money spent to just blow the whole contest on one stupid decision. All of this amounts to, the closer we get to the ground, the more enticing it becomes to take bigger and bigger risks.

Now, one may point out that just because a pilot wants to avoid the loss, there is still a point where the pilot must accept his fate and land. That the stark reality of the situation forces his hand. However, perhaps one of the most dangerous aspects of soaring is that this is simply not so! This leads to the answer to the second question of why it is so difficult to assess risk in soaring.

I believe this is because there is very little objective feedback to the risk we actually take.

Soaring is a particularly unique sport because the actual risk that we experience in a sailplane is entirely statistical and our assessment of it is very psychologically driven. 

The problem with soaring is that there is a very discrete difference between flying and not flying. You could clear the last tree in a tree line by one foot, while one knot over stall and succeed making a transition. Or you could get away with thermalling out from 180ft. Or for most of us, we’ll be quite scared even 50-100ft higher in both scenarios. But my point is that the fear is not driven by the direct feedback that you are right on the edge of death. The big problem is that being on the edge of death like that, nothing actually happens. It just so happens that if you screw up, one wing will drop and the last thing you will see is the ground rushing up at you.

The leads to two problems. The first is that some people mistake getting away with such things to believe that the risk is lower than others believe or that they can handle it. And they’ll probably get away with it again and again, until the one time they get killed doing it. However, most people don’t fall in this category and generally others take notice of this sort of behavior. Rather, most of us can be affected by the strong temptation to avoid accepting a landout. This is particularly sinister, because the very act of delaying acceptance greatly increases the risk to bodily harm. When a pilot really does not want to land out, at 500ft he tries to turn, why not? Then at 450ft, he keeps trying to nibble. And then finally at 350ft, he’s starting to drift a bit far from the field and now it becomes a very dangerous situation. In the span of a minute, the pilot went from a manageable landout situation to one that could cause him to crash. 

The solution is to understand and accept where the true risk is in this sport and mitigate it as much as practicable. Set a hard-deck for yourself and stick to it. Once you commit to landing, follow through with it. Realize that the bigger the loss, the more you will be tempted. 

And when it comes to others and club members, help to lower the feeling of loss. Make landouts accomplishments rather than travesties. Make heroes out of those that called it quits earlier rather than the fellow that dug it out from 200ft. Changing the culture helps to make everyone safer.

Kahneman, D. (2011). Thinking, Fast and Slow. NY, NY: Farrar Straus and Giroux.