NATS publishes preliminary report on technical incident of 8 September

zrail

Note: NATS the UK airspace manager, not NATS the pubsub system.

fotta

link to the report (pdf): https://www.nats.aero/wp-content/uploads/2026/09/NATS-Prelim...

macguillicuddy

Interesting! Looks like a race condition (with a 1ms window) during squawk allocation (the process that gives each aircraft a 4 digit identifier for ATC purposes) caused data corruption. They present that window as being small but 1ms is a decent chunk of time in our work lol

lukaslueg

Would be interesting if the report actually got into the details. The curiously specific "approx. 1ms window" sounds like an off-the-shelf memory race condition in combination with a preempting thread, for which 1ms is an absolute eternity and Guaranteed To Happen By Tuesday This Week™. But the "database corruption" sounds like database IDs being generated from timestamps with 1ms granularity.

ExoticPearTree

A few years back, NATS went down because a flight plan waypoint confused the system and it crashed. They had to manually find the problematic flight plan, remove it and start the whole system back up. Considering the last issue they encountered, it looks like in more than one place, there is no error catching and graceful resolution for those errors. I would assume a system of such importance to handle issues without hiccups and alert the operators of what did not work. Like “this input caused this problem”, not just crash.