Flight Crew Expectation Bias – Finding a Flight Plan for Clarity

what is expectation bias

Ever tried putting your expectations on an all-too-high pedestal – only to see them plummet right back down?

This is what expectation bias is all about – we expect a certain outcome, but it doesn’t always match up with reality.

In the aviation industry, where a split-second decision can mean the difference between safety and disaster, pilots must be aware of expectation bias and know how to mitigate it.

What is expectation bias?

Expectation bias, or observer-expectancy effect, is when people’s assumptions about an event can affect the event’s results. This happens when people’s expectations about the outcome influence how they perceive or interpret the information.

Expectation bias is when people see what they expect to see instead of what’s actually there. This can take different forms, like ignoring contradictory evidence, misunderstanding vague information, or selectively gathering data that agrees with pre-existing beliefs.

Why does it happen?

Our brains have evolved to recognize patterns and make sense of the world around us, which is helpful but can also lead to cognitive shortcuts and errors. When faced with uncertain or complex situations, our minds tend to rely on familiar frameworks or mental models to process information quickly. However, this dependence on preconceptions can be misleading, especially when it comes to objectivity and critical thinking.

Remember the time you expected a fun evening watching Arsenal with a T-bone steak and pint, but it ended up being cleaning and rearranging closets to The Real Housewives of Beverly Hills? That mismatch between your expectations and reality showcases expectation bias, turning your envisioned great Friday into a mix of frustration and confusion.

And yes, this happens in aviation, too.

Pilots may have expectation bias, where they anticipate certain conditions or outcomes based on prior experience or assumptions and may not prepare for or respond to deviations from those expectations. For instance, if a pilot is used to flying in clear weather and expects the same conditions, they may not take appropriate measures to prepare for unexpected turbulence. Similarly, if a pilot has flown a particular route many times and expects the same traffic patterns or airspace restrictions, they may not notice changes or updates that require them to adjust their approach.

Accidents & Incidents

Why Crew Resource Management training is important

1. Spanair Flight 5022, 2008

On August 20, 2008, Spanair Flight 5022 crashed while taking off from Madrid-Barajas Airport. The domestic flight was going from Barcelona to Gran Canaria with a stopover in Madrid. The plane, a McDonnell Douglas MD-82 carrying 172 passengers and crew, failed on its second takeoff attempt because the pilots didn’t deploy flaps and slats, which are essential for lift. The plane stalled and crashed.

The cockpit recordings showed the pilots didn’t complete the After Start checklist by setting and checking the flap/slat lever and lights. The copilot repeated the correct flap and slat position values in the Takeoff Imminent verification checklist without checking them. All three safety barriers that were supposed to prevent takeoff in an inappropriate configuration failed. These were the configuration checklist, the confirm and verify checklist, and the Takeoff Warning System (TOWS).

2. Comair Flight 5191, 2006

On August 27, 2006, Comair Flight 5191 was scheduled to depart from Blue Grass Airport (KLEX) in Lexington, Kentucky, at around 6 a.m. The pilots were cleared to take off from Runway 22, which was 7,003 feet long. However, the taxiway from the terminal to this runway crossed Runway 26, which was only about half the length of the planned departure runway.

Unfortunately, the pilots mistook Runway 26 for Runway 22 and rolled onto its centerline. They only realized their mistake too late, and the takeoff resulted in a devastating crash, killing everyone except for the first officer.

Several factors contributed to this tragic accident, but one of the main ones was expectation bias. The pilots saw a runway and expected it to be the one they were cleared to take off from. If they had paid more attention to the airport diagram or checked their heading, they could have prevented the accident.

3. Southwest Airlines Flight 4013, 2014

A Boeing 737 operated by Southwest Airlines landed at the wrong airport in Branson, Missouri, during nighttime VMC. The flight was scheduled to fly from Chicago Midway International Airport to Branson Airport.

The flight crew reported to have the airport in sight. They were cleared for the visual approach, but despite the correct destination airport being depicted on their cockpit displays, they visually identified the wrong airport as their destination. The pilots did not reference their cockpit displays once the airport was in sight, which led to the wrong landing. The aircraft stopped at the end of the 3,738-ft runway after a hard application of the brakes.

Mitigating expectation bias in aviation

Aviation can mitigate expectation bias through a multifaceted approach involving training, technology, and organizational culture.

How to manage expectation bias

1. Expect changes

Expect changes. It could be that you were looking forward to flying with your cockpit bestie, but a roster change occurred. Or you were expecting smooth sailing during approach and then encountered wind shear. Or you were planning to take runway 14L, but due to a malfunction, you need to use runway 22R.

It’s essential to remember that unexpected things can happen. If we expect everything to go according to plan, we will be in for a rude awakening. Personally, I grew up dreaming of becoming a famous actor touring with George Clooney. I’m now a pilot and the owner of NaviMinds.

With the risk of sounding like Martha Stewart, expect the unexpected.

2. Understand the effects of expectation bias

Aviation professionals should be more vigilant in recognizing expectation bias and its potential consequences. Training programs should include modules on cognitive biases, emphasizing the importance of maintaining objectivity and scepticism in decision-making.

Flight crews should be aware of their own biases to mitigate the risks associated with expectation bias and actively work to counteract them. This can involve strategies such as seeking out diverse perspectives, maintaining open communication with other crew members, and engaging in regular training to stay up-to-date on best practices.

Try our FRAMEWORK© group exercise in your CRM training to highlight the impact of cognitive biases.

3. Cross-check and verify

Encouraging a culture of cross-checking and verification can help counteract the effects of expectation bias. Pilots should actively seek out alternative perspectives and verify critical information, especially when it deviates from their initial expectations. This can involve consulting multiple sources, including weather reports, ATC communications, and onboard instruments.

Raise flight crew awareness’ on expectation bias

Word cards for Framework exercise

Expectation bias is a significant challenge in aviation, where quick decisions can have serious consequences. Understanding the underlying mechanisms of this phenomenon and implementing proactive mitigation strategies is essential to help pilots make good decisions. By being aware, educated, and implementing procedural safeguards, we can ensure the skies remain safe for all travellers.

To help pilots better understand the strength of expectation bias, we have designed the FRAMEWORK© exercise. This exercise is unique in that it allows the flight crew to experience firsthand how easily cognitive biases are created and how difficult it can be to manage them. It also provides some tools for mitigating them.

Anne Knudsen

Anne Knudsen

Anne's career began in the late 80s as a cabin crew, and she was quickly drawn to the world of flying. After a few years, she became a pilot and flight instructor in several larger airlines. Presently, Anne holds the role of CEO at NaviMinds.

Request quote

Request quote

Any questions?