U2?

[Gibbon]

It's to do with re-entrant tracks. NAS, which was an american interstate system at heart, down at the old West Drayton site had the same problem with trans-atlantic flights once the scottish mainframe had set itself on fire.

Basically flights would come into British airspace near scotland, then leave and go into Irish airspace before again entering British airspace. It been an old 1950's system cobbled together in JOVIAL, it couldn't cope very well.

[vetran]

lack of altitude information in a flight plan? Not exactly robust.

But a U-2 operating at high altitude that day had a complex flight plan that put it close to the system's limit, the sources said.

The plan showed the plane going in and out of the Los Angeles control area multiple times, not a simple point-to-point route like most flights, they said.

The flight plan did not contain an altitude for the flight, one of the sources said. While a controller entered the usual altitude for a U-2 plane - about 60,000 feet - the system began to consider all altitudes between ground level and infinity.

[zeitghost]

Gosh.

Exclusive: Air traffic system failure caused by computer memory shortage | Reuters

Must have been a complicated flight plan then.

Just as well they've retired the SR71