Christina, a student pilot in Florida, writes: My CFI was telling me about expectation and confirmation bias today, but I couldn’t help wondering: Is this really a thing? I mean, I understand the theory — on paper — but it’s hard for me to get my head around it really happening. Is this truly a serious threat?
I agree that when you read about bias (hidden exclusively in the FAA’s Risk Management Handbook, which no one actually reads), it’s hard to get your head around. It’s easy to say, “Well, that’s silly. I’d never fall victim to something like that.”
But it’s real, and I was actually a victim of my own expectation bias just last week. What the hell, I have no pride left at my age. Let me share the story with you.
For background, you need to know that for many years the airport where my plane now lives used magnetic access cards for hangar tenants to get their cars through the security perimeter to drive to their assigned hangars. The cards were thick white rectangles, about the size of a typical ID badge. To get into the airport, you’d lay the card flat on a silver plate that was on a little arm near the entry gate. There would be a loud series of beeps, then the gate motor would come whirring to life, followed by a Ghost-of-Christmas-Past rattling of chains. Then, with the squealing of un-greased wheels, the gate would claw itself open for you. Coming out, there was some sort of underground magnet that could detect your car and open the gate without the card, but with all the same acoustics.
That worked fine and dandy until the magnetic card manufacturer — apparently the only one left in the country — folded. So then, as the cards reached the end of their service lives, and there weren’t enough to go around, the airport authority bought one of those little lock boxes that real estate agents use to store keys in for house showings, and used it to store a single “community card.” The lock box was attached to the chain link fence near the gate.
Anyway, so to get in to the airport in this new card-short environment, you’d now have to pull up to the gate, get out of your vehicle, walk over to the box, enter a code by spinning four suitcase-style rotary number wheels (that would always stick and not want to move), open the box, remove one of the last functioning magnetic cards, take it to the reader, slap it on the silver plate, wait for the gate to start to open, then run the card back to the box, get the stupid box to lock again with the same sticky number wheels, and then dash back to your car hoping you’d get through the gate before the damn thing closed again.
Then, securely inside the perimeter, you could go fly.
Last week, when I got to the airport it was raining, so I had to do the entire ritual one-handed, while holding an umbrella. Only when I got the lock box open, the access card was missing. There was only a folded piece of soggy paper in the box. Huh? An IOU? A ransom note? I pulled the paper out and opened it up.
Inside, hand-written in blue ink, was the same code number that I had just entered to open the lock box. And nothing else. What… the…? I stood with the rain pattering on my umbrella trying to sort out this sick practical joke that was denying me access to my airplane. Then I looked over at the gate control. The magnetic reader was gone. It had been replaced by a key pad. The note was left to tell me to just use the same code, but now to enter it directly into the gate reader.
Color me stupid. I had gotten so into the habit of following a certain work flow — in this case the flow to get through the airport security fence — that I totally lost all situational awareness of my surroundings. I didn’t even look at the gate control when I drove up. I could have just unrolled my window, reached out, punched in the code, and been inside. But, no, I just followed my rote routine.
It was a classic example of expectation bias. I so expected things to be a certain way that I ignored all other inputs. In this case, seeing the card reader. As with my gate misadventure, expectation bias is especially common in aviation ground operations.
In actual airplanes, it often happens with taxi instructions. The tower typically clears you via Alpha, Charlie, and Delta 2, so that’s what you do even though this time they told you to go Alpha, Charlie, Delta 3. More dangerously, it can happen with approach and landing clearances, too.
One funny (as in interesting, not ha-ha) thing about expectation bias in radio coms is that pilots will often read back the atypical call correctly, but then their bodies go into autopilot and they do what they expected, not what they were told to do, and not what they read back that they would do.
So, yeah, this is a real thing. And it can have serious outcomes.
Granted, in this case, nothing seriously bad happened. It wasn’t like I wrecked an airplane, got a pilot deviation, or even embarrassed myself (at least until now). But it does illustrate the power of habit and how getting into habits is not always a good thing.
Expectation bias’s cousin, confirmation bias, is a manifestation of the human tendency to “hear” what we want to hear and ignore things we don’t want to “hear.” It’s most prevalent with data analysis in preflight planning, and especially prevalent with weather info. You really want to fly, so your mind latches onto elements of the weather briefing that support flying, while it ignores — or minimizes — data suggesting that today might not be the best day to fly.
And that, too, can be serious.
Deadly serious, literally, in some cases.
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