A closed recommendationrecords the work done, and the next failure arrives another way

VThe Civil Aviation Authority (CAA) published addendum CAP 3193A in June 2026, closing the last two of 34 recommendations from its independent review of the August 2023 failure of the NATS flight planning system. R1 (contingency arrangements) closed after NATS supplied further evidence on the remaining assurance points, and R8 (a senior leadership forum) closed once evidence showed the forum was established. The CAA says all 34 recommendations have been actioned and its reporting to the Department for Transport on that event is concluded¹.

VOn 8 September 2026 the NATS flight data system failed again. The NATS preliminary report of 16 September says a legacy and previously unknown software defect corrupted flight data, and that the incident is not related to the 2023 failure. NATS handled 6,094 flights against about 8,000 forecast, with more than 2,000 delayed, cancelled or diverted².

VUK airport departures were stopped for around four and a half hours over a six-hour period, and all restrictions were lifted at 19:30².

VThe 2023 recommendations did shape the response. NATS says the dedicated Major Incident Manager role, created after 2023, was in use, and that earlier recommendations were implemented and independently verified by the CAA².

VThe 2026 fault arrived by another route. A valid request for a squawk code was paused by a higher-priority message, and a window of about one millisecond left the data corrupted. The first sign came at 10:02, a link drop that cleared after 45 seconds, and at 10:06 the engineering ticket recorded the system as stable. The major incident began at 12:32².

AResponse arrangements begin when someone declares an incident, and this one began as a brief fault that recovered by itself. Closure evidence shows what was built to answer the last failure. It says little about how the next one is detected.

VThe CAA's independent review of the September failure covers how well recommendations from previous reviews were implemented, NATS's plans to renew and replace critical operational systems, and the effectiveness of the CAA's own oversight. Its initial report is due by the end of January 2027 and its final report by 8 March 2027³.

VNATS's own investigation, due within 60 days of the incident, will review defect records, system health monitoring, change activity and asset lifecycle management for the failed equipment, and the application of lessons from earlier investigations².

ARegulators, boards and insurers read a closed item as a lower risk. Where the evidence behind closure records completion, that reading is stronger than the evidence under it.

AKIS PLUS LTD's view is that a closure record should say what the evidence shows about effect as well as completion. Three additions would do it: for each closed item, the failure it addresses and the failures it leaves out; a retest date, when a drill or inspection shows the fix still holds; and a periodic read of the defect records, health monitoring and lifecycle status of the oldest systems under the same owner.

IIf the CAA review finds that the 2023 closures held for incident handling and left legacy defects out of reach, the lesson for other owners is to ask of every closure what it omits. The review has not reported, and this article draws no conclusion on NATS.

OUR PERSPECTIVE

Closed tells a board the work is done. A retest date tells it the work still holds.

1. For each recommendation we have closed, what evidence showed it worked, and which failure does it leave uncovered?
2. When did we last test a closed item, and who owns the date of the next test?
3. For our oldest systems, could a board read the defect record, the health monitoring and the lifecycle plan today?