Separation Monitoring Function

[ATC Watcher]

For the PRuNe guys at LATCC : it seems you have devised a system that has impressed EATCHIP so much they want to have every ACC in Europe fitted with one. Our bosses want to install one ( home-made) in our Centre sometimes this year.
Any advice you could give us ? Is your system well accepted by the working controllers ?

[2 six 4]

Given the time to work out correct parameters and application SMF is a fair indication of separation but not as accurate a measure as radar. It does also require a sensible approach by managers and safety regulators to alerts. Not all alerts are serious incidents (or even incidents)and some are in known areas which are perfectly safe.

At this point the use of SMF is quite lightly regulated and NATS operational supervisors are generally given unqualified support if they say an alert is not an incident needing remedial action.

Indication of acceptance by the ATCOs is that if the SMF goes off the ATCO has usually already held up their hands and said this was a bit dodgy.

God help us if someone wants to write European rules to standardise this sort of thing.

[U B Nadd]

Also each print-out carries a health warning that says something like: This information may not be accurate and is based on prediction only.

[ATC Watcher]

Many Thanks to both of you. UB : Do you mean that the thing is calculating the minimum didtance based on the prediction of the STCA ? Not on the actual distance once they have passed ?

[10W]

A few facts about SMF. Firstly it is not a LATCC invention but one devised by NATS HQ scientists sponsored by the NATS Safety & Quality empire. It has of course been delivered to the major NATS units since it's the operational areas that need to know quickly about such alerts and deal with them there and then. All the ACCs have it and some of the larger airfields with it being rolled out eventually to most NATS units.

In terms of accuracy it is more accurate than radar since it uses multi radar sources and makes comparisons before using the best quality data. However the health warning is that it does not necessarily show the separation which the controller would have seen on his/her radar. The potential differences though are in the order of 10ths of miles as opposed to whole miles so are accurate enough for it's use.

Also the system does not use predicted data. It uses historical analysis which is why an alert may take a couple of minutes to appear on the system.

As already mentioned it is generally accepted as being a good tool for highlighting where separations were not as they should be and with adequate filtering to reflect the airspace and operating methods coupled with pragmatic guidance for supervisors, the number of alerts which actually result in any reporting action being required are relatively low as a percentage of all the alerts the system finds.

[U B Nadd]

The other major drawback of SMF is that it only shows the two aircraft concerned with everything else filtered out. That means it does not give anything like an accurate picture of the radar as seen by the controller, so the traffic situation cannot be analysed until radar tapes are replayed.

[Euroc5175]

Regarding the SMF, it was developed a couple of bays away from where I am currently sitting. Unfortunately, I can't comment on the subject, as it was developed before I joined the R&D mob, i.e. whilst I was still an operational ATCO over in Maastricht.
However, if you want some formal feedback on the SMF I'd suggest you contact TRD1, R&D, K4 G3, CAA House.
Euroc.