Does ATC run on Microsoft 365?

Maybe every 24 hours a new login password is emailed around the country for good security.

From what I know of the ATC system it's closer to IBM System 360 then to Microsoft 365

Microsoft 363

Give them a couple days and they can reach numerical parity with IBM there!

That's a little unfair to IBM – sure, you're just as beholden to them for life, but at least the service engineer gets to your rack before you know something's gone wrong!

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@nxobject I meant litterally. The ATC system is derived from the IBM 9020 which was itself a set of interconnected System 360 systems: https://en.wikipedia.org/wiki/IBM_9020

I believe it's all virtualized today

That explains the outage. We're just in one of the 5 days of the year they don't cover...

I did a tour of Adelaide airport with Engineers Australia in the 1990s. We visited their obsolete IBM main frame, still running ATC in their computer room. They were tied to it by the certification of the software it was running. Just as you described.

This might be a serious question but it is also the funniest thing I've read all week. Thank you.

Related: https://news.ycombinator.com/item?id=50388001

LOL..

Its more likely the route cause wich is Friday 13th

Microsoft 364

What backup systems exist for air-to-ground communication? Something satellite based?

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> This is a system that's supposed to have it's own built in redundancy and must not go down.

There are contingencies for radio outages, but yeah, everything going down at once (if that's what's happening here, which I doubt) is bad.

There is satellite-based CPDLC or "datacom", but I think most planes that have CPDLC use radio-based CPDLC.

In the worst case: light guns and wing-rocking or flashing the navigation lights.

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Technically, you do not need radios. There are many many uncontrolled airports in the United States, where you can technically fly around without establishing two-way radio communication. It’s doable, but I don’t know if that’s even a scenario pilots test in the simulator during their semiannual trainings.

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You don’t need radio for IFR (as the whole point of a flight plan is that if you lose contact you continue to fly your plan). But you kind of do need radar.

Right, but isn't a lot of that necessary radio aircraft-to-aircraft, like ADS-B? Obviously not ideal, but I thought IFR traffic could feasibly maintain separation without ATC help.

AM Radios are literally everywhere, and very commonly available.

I would hope that airports keep a battery operated radio + antenna in case of emergency with them, to at least communicate with aircraft within visual range of the airport.

I would bet the problem is not strictly the radios themselves, they will still work, Planes can talk to each other and directly to airports, But that there is a large scale highly integrated control center network that failed, and planes can no longer talk to centralized traffic control.

So it falls back to local control, more in the style of visual flight rules. Pilots in existing flights will have to be vigilant and do their own deconflictation and stop new flights out until the network is back up.

All conjecture at this stage of course, but all the radios won't just fail. It is probably going to be a poster child example about the dangers of large scale integration. The attraction of course is that integration is very efficient, the danger is it tend to fail all at once instead of in smaller pieces.

I'm wondering if this is another case of delayed Y2K, where the system suddenly thinks the century part is 19 instead of 20 for a two digit year of 26.

Based on what? Just wild speculation or something you've actually seen about the systems involved?

ATC radio is unencrypted analog for safety and communicability reasons, this shouldn't matter.

Am I missing something notable about today's date?

Friday the 13th

Yesterday I was flying out of lovefield in Dallas and the radios went down. We were stuck for about 10min only thankfully.

Radio is not a nationwide _system_ that can go down. ATC just uses basic AM radio for radio comms.

Sure, but these are no longer connected to the controller's microphone via a long cord anymore.

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Back in the day they had long cords that went all the way to the planes, right up until the Great Plane Tangle of 1967.

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They use third party telecom providers to relay communications between ATC “centers” and remote radio transmitters. It is not purely AM radio and outages have occurred in the past, most recently in September.

https://www.nbcdfw.com/news/tech/a-calamity-disrupting-hundr...

That is true but nowadays the control rooms are separate from the actual antennas / areas being served. These are wired up with more modern comms.

"modern" -> "we stuck digital computers into a purely analog pipeline to make sure it's capable of a wide range of harrowing, incomprehensible failures."

> "modern" -> "we stuck digital computers into a purely analog pipeline to make sure it's capable of a wide range of harrowing, incomprehensible failures."

"we stuck digital computers into a purely analog pipeline, now with software containing a near-infinite amount of lines of code generated by LLMs, to make sure it's capable of a wide range of harrowing, incomprehensible failures."

And everybody here on HN applauds.

Radar multiplexer pipeline is likely down.

I got this just now and seems like you know about this area

Attention: National Radar Outage

https://www.weather.gov/afc/radaroutage

"This page is no longer maintained or updated"

Thank you, that has changed.

Like the freezers in Europe?

No. Completely different.