Expectation Bias

Posted by in Opinion Leaders

I don’t know who first described flying as “hours of boredom punctuated by moments of sheer terror”, but it wouldn’t be shocking to discover the genesis was related to flying a long-haul jet. I was cogitating on that during a recent overnight flight to Brazil. While it was enjoyable, this red-eye brought to mind the complacency which can accompany endless hours of straight-and-level flying – especially when an autopilot is involved.

This post was halfway written when my inbox lit up with stories of a Boeing Dreamlifter – that’s a 747 modified to carry 787 fuselages — landing at the wrong airport in Wichita, Kansas. The filed destination was McConnell AFB, but the crew mistakenly landed at the smaller Jabara Airport about nine miles north. The radio exchanges between the Dreamlifter crew and the tower controller at McConnell show how disoriented the pilots were. Even five minutes after they had landed, the crew still thought they were at Cessna Aircraft Field (CEA) instead of Jabara.

McConnell AFB, the flight's destination, is the Class D airport at the bottom of the chart, about nine miles south of the non-towered Jabara Airport.

McConnell AFB, the flight’s destination, is the Class D airport at the bottom of the chart, about nine miles south of the non-towered Jabara Airport.

As a pilot, by definition I live in a glass house and will therefore refrain from throwing stones. But the incident provides a good opportunity to review the perils of what’s known as “expectation bias”, the idea that we often see and hear what we expect to rather than what is actually happening.

Obviously this can be bad for any number of reasons. Expecting the gear to come down, a landing clearance to be issued, or that controller to clear you across a runway because that’s the way you’ve experience it a thousand times before can lead to aircraft damage, landing without a clearance, a runway incursion, or worse.

I’d imagine this is particularly challenging for airline pilots, as they fly to a more limited number of airports than those of us who work for charter companies whose OpSpecs allow for worldwide operation. Flying the Gulfstream means my next destination could be literally anywhere: a tiny Midwestern airfield, an island in the middle of the Pacific, an ice runway in the Antarctic, or even someplace you’d really never expect to go. Pyongyang, anyone?

But that’s atypical for most general aviation, airline, and corporate pilots. Usually there are a familiar set of destinations for a company airplane and an established route network for Part 121 operators. Though private GA pilots can go pretty much anywhere, we tend to have our “regular” destinations, too: a favored spot for golfing, the proverbial $100 hamburger, a vacation, or that holiday visit with the family. It can take on a comfortable, been-there-done-that quality which sets us up for expectation bias. Familiarity may lead to contempt for ordinary mortals, but the consequences can be far worse for aviators.

One could make the case that the worse accident in aviation history – the Tenerife disaster – was caused, at least in part, by expectation bias. The captain of a KLM 747 expected a Pan Am jumbo jet would be clear of the runway even though he couldn’t see it due to fog. Unfortunately, the Clipper 747 had missed their turnoff. Result? Nearly six hundred dead.

"Put an airliner inside an airliner?  Yeah, we can do that."  Boeing built four of these Dreamlifters to bring 787 fuselages to Seattle for final assembly.  As you can imagine, this thing landing at a small airplane would turn some heads.

“Put an airliner inside an airliner? Yeah, we can do that.” Boeing built four of these Dreamlifters to bring 787 fuselages to Seattle for final assembly. As you can imagine, landing one of these at a small airport would turn some heads.

The Dreamlifter incident brought to mind an eerily similar trip I made to Wichita a couple of years ago. It was a diminutive thirty-five mile hop from Hutchinson Municipal (HUT) to Jabara Airport (AAO) in the Gulfstream IV. We were unhurried, well-rested, and flying on a calm, cloudless day with just a bit of haze. The expectation was that we were in for a quick, easy flight.

We were cleared for the visual approach and told to change to the advisory frequency. Winds favored a left-hand pattern for runway 36. Looking out the left-hand window of the airplane revealed multiple airports, each with a single north-south runway. I knew they were there, but reviewing a chart didn’t prepare me for how easily Cessna, Beech, and Jabara airports could be mistaken for one another.

We did not land at the wrong airport, but the hair on the back of my neck went up. It was instantly clear that, like Indiana Jones, we were being presented a golden opportunity to “choose poorly”. We reverted back to basic VFR pilotage skills and carefully verified via multiple landmarks and the aircraft’s navigation display that this was, indeed, the correct airfield.

That sounds easy to do, but there’s pressure inducted by the fact that this left downwind puts the airplane on a direct collision course with McConnell Air Force Base’s class Delta airspace and also crosses the patterns of several other fields. In addition, Mid-Continent’s Class C airspace is nearby and vigilance is required in that direction as well. Wichita might not sound like the kind of place where a lovely VMC day would require you to bring your “A” game, but it is.

Expectation bias can be found almost anywhere. I’d bet a fair number of readers have experienced this phenomenon first-hand. In my neck of the woods, MCAS Miramar (NKX) is often mistaken for the nearby Montgomery Field (MYF). Both airports have two parallel runways and a single diagonal runway. Miramar is larger and therefore often visually acquired before Montgomery, and since it’s in the general vicinity of where an airfield of very similar configuration is expected, the pilot who trusts, but – in the words of President Reagan – does not verify, can find themselves on the receiving end of a free military escort upon arrival.

Pilots in the Southern California area have been known to mistake the former home of Top Gun, MCAS Miramar, for the smaller Montgomery Airport at the bottom of the map.

Pilots in the Southern California area have been known to mistake the former home of Top Gun, MCAS Miramar, for the smaller Montgomery Airport at the bottom of the map.

Landing safely at the wrong airport presents greater hazard to one’s certificate than to life-and-limb, but don’t let that fool you; expectation bias is always lurking and can bite hard if you let it. Stay alert, assume nothing, expect the unexpected. As the saying goes, you’re not paranoid if they really are out to get you!


This article first appeared on the AOPA Opinion Leaders blog at http://blog.aopa.org/opinionleaders/2013/12/03/expectation-bias/.