[tz] GPS Week Number Rollover Apr 6/7

[Paul Eggert]

On 4/1/19 1:28 PM, Brian Inglis wrote:
> If my script is correct, the rollover occurs at the indicated instant on the
> time scales below:
>
> 2019 Apr 06 Sat 23:59:42+0000

That hits a bit close to home, as I'm scheduled to take a US commercial
flight that will take off about two hours after that.

As it happens in my software engineering class today I talked about
AeroData's nationwide outage this morning, and now you're prompting me
to speculate whether that outage was related to the GPS rollover.
Although AeroData hasn't said publicly what caused the problem, the
Orlando Sentinel reports that it was related to GPS and it's not beyond
the realm of possibility that a flight-planning application would use
prospective GPS clocks that wrapped around. (Of course I'm just guessing
and could easily be quite wrong.) See:

Pedersen JM. Nationwide glitch impacts flights at Orlando airport;
Southwest, JetBlue most affected, official says. Orlando Sentinel.
2019-04-01 08:05 -04.
https://www.orlandosentinel.com/news/breaking-news/os-ne-oia-aero-data-glitch-20190401-story.html

The outage caused hundred of US flights to be delayed today. See:

Gallagher S. Flight management system crash causes airline delays across
US. Ars Technica. 2019-04-01 16:34 -00.
https://arstechnica.com/information-technology/2019/04/flight-data-system-outage-causes-april-1-airline-delays-no-fooling/