A very constructive post by dfc and a possible insight overlooked by the aaiu team which he mentions in his ps comments. At a 250 mile range the physical distance of 5 miles appears much "closer" on a radar screen than 5 miles looks on a radar screen at 135 mile range.
PS The report did not dwell on one very important issue. With the display on 250nm range measure the distance on the screen between two tracks 10nm apart. Now change the range to 150nm. Those aircraft appear to move appart. With a tired mind, end of shift distractions, cluttered airspace lines etc it would be easy to allow one's mind to use the same visual on screen distance to represent a minimum of 5nm when now it is actually less than 5nm.
STCA suffers from false indications especially when aircraft are changing level at high rate.
Combine the two and one could see a situation where the controller could think that they had more distance than they actually have and the initial STCA would be initially counted of as unreliable.........but then on checking the controller would realise the error and take corrective action - as in this case.
Is there a 5nm reference available to the controller in that area of the sector?
There is no 5 mile reference anywhere in the system. One can be drawn by using the qdm tool and some do just to remind themselves what 5 miles "looks like" when operating at a much smaller range after operating a period of operating at much bigger ranges.
How many Atco out there in other centers operate on ranges out to 250 miles regularly?
One thing of interest to me is that when the initial instruction was issued for the ryr to descend thru the flt a third non involved aircraft (malev) i think took the call. .This necessated the controller to make another transmission to tell the malev to disregard the intruction and then reconfirm the instruction with the ryr-which lost a valuable amount of time . I just wonder if the ryr had gotten the first call would it all have worked out ok? Who knows.
Some more credance should also be given to the "sytemic,training and procedural" issues identifed in the report. Human error is given as the primary cause but the other factors are just as important. TRM every 3 years now recommended to once a year/year and a half. The TRM itself to be changed and include a culture of active "challenge" as pilots do.
That a study be performed and recomendations made on the on-suite allocation of tasks between the radar and planner.And a standards officer to be appointed to co-ordinate between operations and training. . Of the 3 recommendations all 3 three are important but emphasis should be given to the first 2.
On a purely personal note-a message of support and good will to those involved. It cant be easy but your colleagues support you.
Yours as ever
OCK1F