All those problems were generated in a millisecond….
The incident on 8 September was caused by a software defect in a small part of the National Airspace System (NAS). This underpins the management of UK airspace.
So, what exactly happened? While a manual request for an aircraft code (squawk) was being processed, the system received a higher priority activity message, which resulted in the earlier request being paused. When processing of this request resumed, the software defect meant it did not restart correctly. The resulting output was corrupted, which then affected some subsequent flight data updates. Apparently, this happened in the space of a millisecond.
In its formal layout, the report consists of 18 pages, including a covering statement from NATS CEO. This report covers the actions and investigations undertaken in the 72 hours from start to the final coordination call with aviation stakeholders on 11 September.
Controllers at London Area Control (LAC) had lost access to some live flight data and invoked practised fallback procedures. This included coordinating the manual handover of aircraft between neighbouring national and international ATC. As expected, this usually happens automatically. Controller workload increased dramatically, so aircraft numbers were reduced to maintain safety margins. This included limiting or stopping departures from UK and overseas airports. With the number of arrivals exceeding departures, increased ground congestion led to diverting inbound aircraft already airborne. At all times, controllers were able to speak with the aircraft and monitor them on radar.
Analysis identified that flight data had corrupted because of a legacy and previously unknown software defect, together with a combination of very specific events happening simultaneously. At this stage, there is no evidence to suggest it was caused by a malicious act or cyber related event.
Whilst the full scale of disruption will take time to confirm, NATS stated that more than 2000 flights were delayed, cancelled or diverted. They also handled 1800 fewer flights than forecast for that day.
The report contains a detailed timeline of the incident, starting at 10:00 on 8 September through to 08:30 on 11 September. NATS has Incident Management procedures in accordance with a Resilience Plan using a Gold, Silver and Bronze hierarchy. There’s also an Air Traffic Incident Coordination and Communication Cell (ATICCC). Its function is to hold briefing calls throughout an incident with airlines, airports, other airspace users and stakeholders ensuring that everyone gets the same information at the same time. The Major Incident Manager (MIM) and team ensured a coordinated response and recovery effort. This role set up after the 2023 incident.
As expected, there’s a terms of reference list for the full Major Incident Investigation report which will be published within 60 days. The full preliminary report is available on the NATS website.
Both MOD and the RAF were quick to announce it wasn’t them. Many “experts” took to social media, broadcasting their theories on what happened. The person suggesting the BA LHR-PVG diversion to CWL was a cyber-attack has remained quiet. No doubt after discovering that the airline has a large maintenance facility there. The flight subsequently operated non-stop from CWL. EK31 which diverted to BHX, returned to DXB 2 days later as a repositioning flight.
Did you spot any unusual aircraft at your local airport because of the incident? If so, please share…
In other news –
Air Baltic – announced they had filed for Chapter 11 bankruptcy protection in the USA. The reason given they want to restructure and refinance. After their initial success with fleet and route expansion, they are struggling with increased fuel prices. Expanding their A220 fleet to 100 has been shelved, with plans to reduce to 40.
Britten Norman – the first Islander from their Bembridge UK production line completed its maiden flight on 3 September. Serial no 2317 will now undertake a detailed flight test programme.
FR24 – recently visited Tarmac Aerosave at Tarbes, to find out what happens when aircraft reach the end of their useful life. They notice the Global A380 so had to ask what was happening to it. The official reply, it’s in storage!
And finally –
Cranky Dorkfest – the annual enthusiasts event took place at LAX on 19 September. Organised by Cranky Flyer, it consists of a ramp visit followed by the main event. That’s held in the park across from In-N-Out Burger, an extremely popular spotting location and no doubt good for trade! The ramp visit takes place outside the Flight Path Museum, an ideal spot to watch departures and arrivals. Some static aircraft are also available for enthusiasts to “crawl around on”. Anyone can attend but only those who have RSVP’d are entered into the prize draw. Detailed information available on crankyflyer.com
Emirates – congratulations to Captain James Ward on recently completing 10 years at the Middle East carrier. He previously worked for easyJet based at BRS. Having transitioned to the A350, he’s sampling new destinations. In line with his employer’s wish to have A380 pilots certified on the A350, there’s still a possibility we may see him again at LHR/MAN/BHX…
Information courtesy of NATS, Britten Norman, Air Baltic, Tarmac Aerosave, Cranky Flyer, Emirates
Images courtesy of The Pulse Signal, Airline Reporter
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