GA1389 - Runway incursion narrowly avoided

Initial Report

I flew into [Airfield] in February. As usual at this time of year, the grass runway XX/YY was NOTAM’d out of use. Arrival on runway ZZ was not exceptional. [Diagram of runway orientation provided below for clarity]

On taxiing for departure in early afternoon, it was clear that the need to backtrack ZZ was going to lead to a bit of delay due to circuit and arriving traffic. I joined the departure queue as number 4 behind a weight shift microlight and two light twins. The microlight managed to take advantage of a runway slot and quickly departed before the stream of crosswind arrivals and circuit traffic resumed.

After several minutes, another brief slot opened and the first twin backtracked and departed. Once again, the relentless stream of arrivals and circuit traffic resumed. All this time, aircraft were calling to taxi and joined the queue. After several more minutes, one of the circuiting aircraft extended downwind to allow the second twin to get away on his pipeline inspection task.

I was now at the head of the queue for the runway, but the relentless stream of arrival and circuit traffic resumed. As the circuit aircraft landed, it was a relief to see a slow-moving aircraft join downwind and I estimated I had sufficient time to backtrack and depart without impacting his approach.

I called “backtracking ZZ” and started to move forward. Immediately an aircraft behind me in the queue called “I would remain where you are if I were you, there is an aircraft about to depart”. Somewhat baffled, I executed a quick 360, resumed my position and transmitted a sheepish apology. I will be forever grateful to whoever made that call.

A few seconds later, a high-performance aircraft took off from ZZ and cleared to the north west.

My departure plan had assumed that, with the XX/YY NOTAM in place, that the only available route to the runway was via QQ threshold. This expectation was reinforced by the local aircraft who were clearly respecting the NOTAM.

The departing aircraft had indicated its intentions on the RT as the local aircraft had clearly picked up on it. I had assumed that departing aircraft were all joining the queue behind me, and didn’t really listen to them. My focus was on aircraft in the circuit and trying to identify a suitable gap.

I would like to claim unfamiliarity with [Airfield] as a visitor, but I am quite a regular visitor – probably 4 or 5 times a year. I should have picked up on the transmissions of the departing aircraft. My only explanation is that the NOTAM had created a blind spot to the possibility of aircraft disregarding or being unaware of it.

Reporter’s lessons learned

Complacency – just because a facility is unavailable, doesn’t mean someone will not use it
Pressure – this was probably the busiest circuit I have ever experienced.
Resources – my focus was on airborne traffic to the detriment of aircraft behind me.

CHIRP Comment

The airfield concerned is a CAA licensed aerodrome with Air Ground radio only.

This report highlights just how easily expectation bias and task focus can influence decision-making even before getting airborne, especially in a busy, high-workload environment. The reporter had formed a mental ground picture, based on the NOTAM and their expectation. This was reinforced by the other visible aircraft and led to an understandable but incorrect assumption about where aircraft could be expected to route. Combined with the reporter’s strong focus on airborne traffic and finding a precious gap to depart, this created a blind spot to the radio transmission which would have provided vital spatial awareness. This report also highlights the importance of careful reading and interpretation of NOTAMs; on this occasion, was the runway out of use for all operations including taxying, or was it just unavailable for take-off and landing?

In aviation, it’s easy to make assumptions and become fixated on one element of the task, especially when there’s a high workload and pressure, real or perceived. In this case, it was uncertainty about squeezing into a busy circuit and the knowledge of aircraft queuing behind. The key takeaways are: how quickly situations can change and how it is easy to miss a vital piece of information when attention has been prioritised elsewhere.

Fortunately, the reporter made a timely R/T call to announce their intentions; thus, the unfolding hazardous situation was picked up by another waiting pilot, who spoke up and saved the day. What a great example of successful teamwork and therefore the incident being just chalked up to a ‘near miss’. This radio intervention prevented a potential runway incursion and underlines the value of good communication and mutual vigilance, particularly at airfields with only an Air Ground service where pilots carry more responsibility for situational awareness and separation.

The reporter did an excellent job of analysing the human factors at play here, even if they were a little hard on themselves. We all make mistakes, but what and how we learn from them is a measure of our calibre as aviators. We commend the reporter for their honesty and willingness to share this experience. Rather than brush it off, they reflected, identified where assumptions had crept in, and recognised how their attention had narrowed. This kind of insight is exactly what helps others avoid similar situations. It’s a valuable reminder that, even at familiar airfields, staying alert to the big picture and expecting the unexpected is essential to safe operations.

Dirty Dozen Human Factors

The following ‘Dirty Dozen’ Human Factors elements were a key part of the CHIRP discussions about this report and are intended to provide food for thought when considering aspects that might be pertinent in similar circumstances.