Whats happened to London ATC as of 2030UTC?

[OneWorld22]

Major computer failure, no traffic being accepted in London or Manchester airspace, Brussels is hit as well.

[North of the Border]

Maybe someone in management switched it off trying to increase delays/decrease movements to avoid paying out on our bonuses

NOTB

[Stan Sted]

Seems that it was down for about 20minutes.

SS

[Numpo-Nigit]

HCS version 2609, which contains software essential for Swanwick operations, was introduced on Thursday 2nd. At 2025 on the 3rd HCS failed - draw your own conclusions. It was about thirty minutes before a reliable system was available again. Luckily it was a relatively quiet traffic situation. Let's hope that this weekend does not degenerate into a carbon copy of that nightmare scenario a few months back when the Saturday suffered several hours' worth of computer failure following a similar software introduction.

[Numpo-Nigit]

During the morning of Saturday, a decision was made to revert to the previous version of HCS software. The problems yesterday apparently are with the "Irish Gap" processing. I'd bet that it was unlikely that a rapid fix could be made 'cos they've been trying to get the Irish Gap working OK for several years now. So, it remains to be seen if there is a knock-on effect on NERC as version 2609 contains essential NERC-related software. Watch this space.

[identnospeed]

Sat morning 0630 - no strip outfall for Stansted arrivals and deps after new version installed.

INS

[highlevel]

Numpo, just out of interest, whats the Irish Gap?

[Numpo-Nigit]

When the computer was first installed at LATCC, it was only intended to cater for LATCC airspace. The original plan was that ScATCC would have its own computer in the fullness of time. That plan never came to fruition for various reasons, and it was subsequently decided to extend the area of operations of the LATCC computer to cater for ScTACC airspace. That was a large but relatively straight-forward task, except for the processing of one category of flight. Those which start in or transit LATCC airspace, then go into Shannon airspace, and then re-appear in ScATCC airspace (or in the reverse direction) have been a headache from the start. They've tried using two separate flight plans for the two segments or, as now, one plan with complicated software rules. Whatever they try, there always seems to be a problem with flights that cross this "Irish Gap". It seems that this processing has, once again, been the downfall of a new software version.

[10W]

It's Irish Airspace lying between London and Scottish.

For example, a flight coming through 55N 10W and routing via STU will first be processed by NAS for Scottish airspace. It will then pass online data to Shannon via OLDI. Shannon in turn pass it via OLDI back to LATCC through NAS again. Because of system parameter times there are difficulties in changing data on the flight, or getting the data out on time at the receiving UK sector. Various fixes have been proposed over the years, none of which have been too successful. Seems the latest offering is going the same way judging by the comments above.

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10 West
UK ATC'er
[email protected]

[highlevel]

Interesting, thanks for the replies guys.

We seem to get problems with ACT transmissions via OLDI to Scottish more regularly than other adjacent Centres. I should know the answer to this myself, but is an ACT acknowledgement (LAM) incumbent on the actual ACT being accepted into the receiving centres system, or only that the actual one line message as transmitted has been received?

I thought that it was only an Acknowledgment of receiving the message, but on the OLDI lines to Dublin ACC, if their system does not like the ACT for some reason, eg. squawk code clash, then it seems to rejects it and we do not get a positive indication that the actual ACT has been received.

Traffic routing STU-55N10W almost always creates extra work for us, we dont get a copy of the ocean clearance for these flights and so have to enter dialogue to establish the Ocean Entry Point, cleared ocean level, any time restrictions we may need to implement as Scottish would not have time to do this between handover and exit, and when the aircraft wants to be at that ocean level (ie. for us to determine what level the ACT should be sent at)