Robust systems are designed to avoid single points of failure. Humans are fallible. So, for example, both the pilot and the air traffic controller are intended to be paying attention so that if one of them makes a mistake the other can pick it up. If the pilot is making an error, the air traffic controller gets on the radio to tell them they're getting too close to another aircraft, in time for them to course correct.

If air traffic control is under-staffed, now the warning the pilot gets might come a minute later than it would have otherwise, and already be too late. Then you no longer have a robust system and it's only a matter of time before one of the pilot errors the system was designed to be able to catch in time instead results in a collision.

There's obviously some number of mistakes one party can make in a single incident such that the other has a limited probability of preventing an accident. If flight control is the robustness, it would take flight control with a lot of free time to be reducing those mistakes in pilots by following up on all sorts of errors unrelated to an incident until a pilot rarely makes multiple overlapping mistakes.

You're still going to try to reduce the errors by each party as much as you can. The point is that if they each do the right thing 99.9% of the time, the overlap allows you to prevent a problem 99.9999% of the time. Whereas if you compromise one of them so that it's 80% instead of 99.9%, the chance that something makes it through the net increases by a factor of 200.

It's not entirely fair to choose this flight as a random sample, but assuming for a moment that it is.. The pilot has a 85% or lower, how many 9s on the controller fix that?

If controllers were like traffic cops they would take time to raise or remove that 85% when they caught it and pay limited attention to current traffic to take actions to reduce future traffic risk. But they are not that as you just explained again.

It's not about a particular pilot, it's about the system as a whole. As long as 99.9% of aircraft don't require any remediation, the air traffic controllers have the bandwidth to catch the few that do. Until you don't have enough air traffic controllers.

The pilot is an example consistent with no actions to correct pilots. Double controllers and these pilots can now fly twice as many missions before they kill someone.

Controllers talk like an extra 9 for them is the focus and it is for them, the public acting like their ceremonies are about fixing the majority of the problem is a bold faced lie.

There are already many actions to correct pilots. But human efforts are never perfect and we don't expect them to be, for both the pilots and the air traffic controllers. Which is why they're designed to backstop one another, and why compromising either one of them increases the probability of a collision.

> If the pilot is making an error, the air traffic controller gets on the radio to tell them they're getting too close to another aircraft, in time for them to course correct.

They did.

Pretty sure military aircraft just don’t have to listen to them.

They did after it was too late, because the crash happened. Unless the crash was intentional (and I'm not aware of any evidence of that), getting the warning sooner could have given the pilot more time to correct.