Originally Posted by
Lake1952
While the exact determination of how close the two aircraft came to each other is the subject of intense scrutiny, it is really only important for the sensational value in my opinion. No matter how small or large the separation truly was, the entire episode was a near disaster that but for providence could have resulted to two incinerated aircraft and extensive loss of life. At the end of the day, this incident should be treated as if the worse case did unfold.... same with the JFK incident. The difference between incidents and accidents is is quite minuscule.
Unfortunately, the changes to the system that take place after incidents is often minimal compared to what happens after an accident.
I agree - the problem isn't how close the planes got but that they had eliminated 99% of the separation they should have had. The same concern should be for taking up 10%, 20%, 30% of that separation.
While separation is typically managed by distance, that model works well under constant velocity conditions. When there is acceleration involved it would be as important to see the separation in seconds. The problem is that it depends on performance models of the aircraft to include run-up delay and basic thrust response. The good news is that this information could be gained solely by ground radar tracking of the aircraft to develop the performance distribution from which one could get the 3-4 sigma limits. Then, any aircraft operating outside those limits could generate an alert that something was severely wrong.
The other might be putting indicators of estimated time to arrival as a billboard display (along with a stop light) to let pilots know when incoming traffic will pass by their hold point. This would be far easier.