Negation: (n.) the act of saying no

Hello dear readers,

We live in a complex world, where decisions are part of our everyday life, and as assertive as you may be, saying no is sometimes difficult, or sometimes not really an option.

Air traffic control sometimes carries an image of a system like that, where ‘no’ is not an option, and the roles are very clear: controllers instruct and pilots execute.

Well, let’s think again. This story is short, but it happened to me a long time ago, as was working at an all-cargo airport.

The schedules were very similar every night: a peak of arrivals between 23h00 and 1h00, and then a peak of departures between 2h30 and 5h.

At the time, the airport was not equipped with a RADAR system that enabled controllers to provide an approach service locally, so our colleagues working in the air traffic control centre some 80km away did it for us. Neither was I qualified to do that, as a matter of fact. I was a tower controller with no surveillance (RADAR) rating.

So, every night, depending on the runway configuration and weather, we would agree with our colleagues who worked the Approach sector on the working method for the shift, and notable on the longitudinal separation that Approach would apply between two successive landings.

That night, in spite of the less-than-ideal weather conditions, we agreed to stick with the standard distance of 5 nautical miles, as all the other conditions were good, no departures were scheduled during the arrival peak and the airport was fully operational.

The problem arose towards the end of the peak, when most of the airplanes were in, but we still had a sequence of 5 aircraft approaching. Number 1 was a twin turbo prop, a Dornier 328 to be accurate, and followed by a British Aerospace Avro RJ100. To let you in on a small secret of the trade, the performance of commercial aeroplanes can vary from one type to the other in two situations: during cruise, and during the last stages of final approach. Otherwise, during the approach process, they are reasonably similar, which makes life a little easier when building a sequence.

But that night, the leading aircraft on final, the Dornier, reduced speed quite a lot on short final, but still made a very long landing, which forced the pilot to keep on rolling until an exit brace that was not very comfortable, as they had to carry out a 120-degree turn and so reduce the taxi speed significantly. And while that happened, the Avro that was trailing him, was struggling to reduce speed, as I kept instructing him and informing him of the situation ahead.

Unfortunately, at some point, it became clear that a landing was becoming impossible, because the runway was still occupied, so I issued a go-around instruction and started calling my Approach colleague. But it didn’t go quite as planned:

TWR: ABC123, go around, I confirm go around, traffic is still on the runway.

ABC123: Negative sir, we land, ABC123.

TWR: ABCI 123, I confirm traffic is on the runway, go around, go around, go around.

ABC123: Negative.

TWR: ABC123, roger. Wind 260 degrees, 13 knots, you are NOT cleared to land, traffic on the runway.

The only thing left for me to do was to instruct the previous landing to expedite vacating the runway, but I realized that the pilot had understood the situation and was expediting already when I talked to him.

Okay. Formally, this was a critical incident. Runway safety was compromised, and big-time. Papers had to be filled in, CAA and runway safety team notified… all in all a big scare for me and a lot of admin, but in the end, fortunately, no accident.

What I would like to address today, I came to realize only after the end of my shift: the pilot of that Avro, who landed without clearance, in his choice, still did a proper job. He probably had a very good reason to refuse the go around, and most importantly, he notified me that he did not or could not comply with my instruction. At least, I had a chance to make sure that the consequences stayed minimal. It is important here to understand that the pilot did the right thing: he refused to go around, he did not question or discuss the instruction, which would have been much more time-consuming, and ultimately, inefficient and dangerous.

Let us compare this situation with an aircraft flying at 250 knots whose pilot receives the instruction to reduce speed to 180. And who reads back the instruction but simply does not comply. Which of the two do you think is the worst? Well, the second of course.

Not being able to comply with an ATC instruction is OK. As long as you say it. Do not let the controller think that you are doing what you were told but then not comply. Or even worse, if an ATC instruction would put you in an illegal, dangerous, or technically impossible situation, do not try to do it, but please manifest your inability to comply!

Imagine you are flying a Cessna 150 and I tell you this:

“G-ABCD, expedite climb to FL 370, maintain a rate of climb of 2000 feet or more until passing FL 270.”

Laughable, isn’t it?

Well, it is exactly the same if, for example, you fly VFR at 3000 feet, the ceiling is at, say, 4200 feet, and you are instructed to climb to 6000… Technically, you could do it, but please do not venture into IMC just because you were told to climb.

One word, that is all we are asking for.


Example: “G-ABCD, unable to climb due clouds”, or “G-ABCD, unable due to performance”

It is part of the job. ATC have a backup plan, so better tell them immediately to use it, it will save time, and increase safety.

Have a nice day, and until next week!