Did you hear what shut down LAX?

[daepp]

1960's tech: U2 shuts down ATC:

http://www.nbcnews.com/news/investigations/spy-plane-fries-air-traffic-control-computers-shuts-down-lax-n95886

[Nostril Cheese]

Um, those things have a lot more sophisticated electronics now than in the 1960's.

We have a few ATC guys on here. Maybe they can share some insight.

[Embraer]

1....LAX wasn't the issue being shut down. Los Angeles ARTCC was the issue. Every bit of airspace from South of San Fran, over boulder city, down towards phx, blythe, san diego, etc was sterilized. We call this "ATC Zero" LAX was a concern...but we also serve many, many other busy airports here in SoCal.

The issue came from the way our automation program and flight data processing interprets altitudes. That article title is misleading...the U2 itself had nothing to do with causing the issue. When we work U2's...they have hundreds of points in their flight plan. Without going into too many details, U2 altitudes are handled in a special way. This issue arose when the flight plan was entered with an alternate altitude that the computer did not recognize. Once the computer went bananas, it started generating flight data strips for each point in that flight plan. Essentially, it entered a closed loop program that just kept repeating and repeating and repeating....crashing the system.

We reverted back to our old system, called HOST in order to safely land and divert airplanes that were in our sky. Once the airspace was flushed, we were able to reboot the system and bring it back online.

Our automation system is new, and this isn't something that anybody at Lockheed or the FAA knew would happen...more or less a freak glitch.

[porsche4life]

Were you working that day mike?

[Embraer]

it was my first day back after 9 days of leave.

[merlinfe]

Crappy first day back.
I usually have to roll my hand over my face and say to myself "What the Fuch..." on days like that.

[Tobra]

Sorry, I laughed a little on hearing it was your first day off after a vacation, nice welcome back.

[id10t]

Originally Posted by Embraer

Without going into too many details, U2 altitudes are handled in a special way. This issue arose when the flight plan was entered with an alternate altitude that the computer did not recognize. Once the computer went bananas, it started generating flight data strips for each point in that flight plan. Essentially, it entered a closed loop program that just kept repeating and repeating and repeating....crashing the system.

Sounds like buffer overflow, data type mismatch, etc. NEVER trust user input - validate & sanitize before doing anything else wtih it.

[atcjorg]

never was a big fan of eram, it always generates too many strips, btw I am 9 months into my vacation, have a good day Mike

[Porsche-O-Phile]

Must be Windows based. That'd never happen with a Mac.

[Don Plumley]

Originally Posted by id10t

That's funny! Shared with all my coder friends.

[Embraer]

Originally Posted by atcjorg

never was a big fan of eram, it always generates too many strips, btw I am 9 months into my vacation, have a good day Mike

the cool thing is...we have it so it normally never prints any strips. I never noticed the thermal printer going off when I first started, just from hearing it non-stop. Now, if it prints one, all of our ears perk up....

[beepbeep]

Correct me if I'm wrong, but weren't flight planing computers updated quite recently (like few years ago), being previously run on hardware that was 40-years old (custom wired PDP-11's or something like that)?

[Embraer]

yes, our new system has been updated.

[Embraer]

Originally Posted by atcjorg

never was a big fan of eram, it always generates too many strips, btw I am 9 months into my vacation, have a good day Mike

only 22 years until im on permanent vacation!