Which give a line of sight difference of 800 feet or less. Which at 45 degrees would be a vertical and horizontal separation of 565 feet. (Change the angle and as vertical increases horizontal decreases so it makes litle difference.) Which is closer than I would like to be. (I have to admit I was expecting to prove the tabloids wrong.) Maybe not all proximity incidents are even noticed let alone reported?
Professor Yaffler
You are welcome to post here and the ATC bunch are normally never shy at coming forward to explain things (but the truth might be less shocking than portrayed in the guter press
)
The minimum distance confirmed by radar recordings was 1000' vertical separation. Absolutely normal in a holding pattern
and in most other parts of the sky.
NATS has equipment called Separation Monitoring Function which continually measures the vertical and horizontal distances between aircraft at all times. It is independent of the ATC controllers suites and will give an alert to the Supervisor if the parameters are breached. These parameters are smaller than the proscribed separation standards since there is some accuracy leeway, particularly in level occupancy by pilots, and numerous false alerts would ensue if it went off at the separation minima. The figure you calculate (565 feet) would fall within these parameters and if that had been the true vertical separation (and the aircraft were within a minimum horizontal separation parameter), then the controllers involved would have been filling in forms and having chats without tea and biscuits. You simply can't not notice an Air Prox event since Big Brother won't let you. And nor will the pilots who monitor their TCAS.
As was pointed out to the press by those in the know when quizzed at the time, there was no incident, because separation was provided as per the standards. No sensionalism can hype up the fact that it was a simple everyday event with no loss of any safety standards. Although some have tried to to sell their rags by trying to make it appear as a near catastrophe
