At Paris-Orly airport, Air Traffic Controllers use a system called DECOR to “communicate weather conditions to pilots.”
The system runs on Windows 3.1 and it crashed last Saturday.
In doing so, it prevented air traffic controllers from giving pilots other critical information—like the “runway visual range” (RVR), or the distance at which a pilot can expect to be able to see down the runway.
Windows 3.1 was released in 1992. It was still Windows in the sense that it was a DOS-based overlay that gave you various windows on your computer screen. It’s the operating system that was made obsolete by Windows 95.
Other airport systems run on UNIX and Windows XP. Tech support for the Windows 3.1 DECOR system is extremely scarce. Apparently there are only 3 specialists who can work on the system, and one is nearing retirement.
A spokesperson for the Ministry of Transport says the system will be modernized in 2017 though others speculate it could be “2019 at the earliest, perhaps even in 2021.”