Assumptions, (lack of) communications, and expectation bias are a triple threat for RIs

Once upon a time…

On a dark and foggy February night in KAUS/Austin-Bergstrom, Texas a FedEx 767 was heading towards runway 18L when a chilling shadow filled their vision. Cleared to land, and passing the threshold, the looming shape of another aircraft – a Southwest 737 – materialised like a mammoth creature emerging as if from the fathomless depths of the ocean.

It appeared through the fog, rolling down the runway. The FedEx went around, while the Southwest rotated, climbing under them. The two aircraft came within 150-170’ of one another. Less than the entire length of the Boeing 767.

What had happened was the SWA had called ready and been cleared for take-off while still far from the holding point. Something the controller was unaware of because of the outside conditions. The SWA also did run up tests on the runway, holding on it for some 19 seconds before commencing their take-off roll. Something the controller was unaware of.

So, how did this incursion occur?

Well, the NTSB have just released an executive summary on it. You can head here and find the full story and that (official) info if you want. No, they don’t mention a ‘mammoth creature emerging as if from the fathomless depths of the ocean.”

They did say that:

We determined that the probable cause of this incident was the local controller’s incorrect assumption that the SWA airplane would depart from the runway before the FedEx airplane arrived on the same runway, which resulted in a loss of separation between both airplanes.

A few things stuck right out from the report though. Comments like:

• The controller’s “incorrect assumption”
• The controller’s expectation bias regarding the actions of the SWA 737
• The controller’s lack of situational awareness regarding the position of the SWA when the flight crew requested takeoff clearance
  • They were 550’ away from the holding point when they called ready
• All the crews’ lack of information regarding the controller’s lack of visual contact with the taxiways and runway (it was foggy out)
• The SWA flight crew’s lack of communication to the controller that they would be doing run ups on the runway
  • They were not required to inform ATC they were planing to stop on the runway
  • They were aware that another aircraft was on short final

But why…?

We are NOT looking to cast blame but to understand how this could have happened. There are a likely a lot of wagging finger looking to blame the controller but first up, that won’t help, and second up, we really have to think about what led to the controller losing SA/ making assumptions/ falling prey to bias etc. because chances are, the full human factors picture will look somewhat different when we really stand back and consider it.

So, let’s ask those questions instead because then (and only then) can we start to think about ways to not have this happen again.

Don’t be this angry, big chinned pilot blaming ATC

It is worth adding now before we dive into the murky mess of this incident that:

• KAUS does not have surface detection equipment for tracking aircraft movement.
  • The FAA have recommended it should have
• The controller had not done any low-visibility training for the last two years and was unfamiliar with the surface movement guidance and control system (SMGCS)
  • A failing in the airport operations/ATCO training department more than with the individual!

Here are the real lessons we think need to be learned from this incident.

Lesson #1

In low visibility conditions, without better detection and surface monitoring systems, ATC need the support of crew to maintain their situational awareness regarding aircraft position.

If flight crew plan to stop on a runway, particularly during foggy conditions, and especially if they know another aircraft is on finals, they should alert ATC.

Likewise with calling ready for departure. Both ATC and crew need to work together to share the mental model.

In fact, this sharing of mental models to support situational awareness and to avoid expectation bias and assumptions should happen at all times, at all airports not just in low visibility conditions. In fact, throw it in on approaches and for landing too!

Lesson #2

Communicate! Expectation bias and assumptions are both best avoided/mitigated through good communications.

ATC cannot know you plan on doing something different to the expected unless you advise them. Pilots cannot know a major safety margin is reliant on them maintaining or meeting certain requirements so if they MUST then they must be told!

‘Bigger picture” situational awareness is only built up through sharing mental models and this means sharing it between ATCOs and crew. Things like the fact ATC were could not visually confirm traffic positions, the fact the SWA crew needed to do engine run-ups…

maybe tomorrow the fact you can’t make the usual exit, or that ATC need you to maintain a certain speed for spacing and the tailwind is stopping you…

Lesson #3

Be alert, look out and listen out!

This is for flight crew and ATC because both roles do make mistakes which is why it is key to confirm clearances actually make sense in the context of the situation, and why it is critical to confirm that no expectation bias or assumptions have clouded the clearance.

If cleared to line up and takeoff, check approaching traffic and check the distance/separation. Don’t assume it is ok, check for yourself! If clearing traffic, make sure they know if it is an immediate required, don’t assume they will.

Summary

It is critical that ATCOs and flight crew:

• Share mental models
• Communicate
• Are alert and aware of threats and able to intervene if needed

And more importantly, that we all start considering HOW to do these three things together, better. Both roles focus on human factors and CRM/TRM within their own role and area of operation, but this should be considered across both roles particularly for times of direct interaction like in this example.

Don’t work together like this. No-one should ever find their face looking like that.