[adhvaryu]

Imagine the dread if they find out who wrote the code.

Also to be honest, shouldn't this have been better unit tested? Considering aviation is a ~ £60 billion industry for the UK.

[monooso]

In their defence, they did manage to process 15 million flight paths before encountering this problem. Some bugs are just really difficult to predict.

[petesergeant]

> shouldn't this have been better unit tested

Entirely possible there was a unit test that confirmed the system would error out in this particular condition. This sounds more like a requirements issue.

[throwaway154]

Not a unit test problem.

Relying on it's unit tested strong systems does not make. There's a lot more to testing.

[krisoft]

> Also to be honest, shouldn't this have been better unit tested?

We don't know how well it was tested. (unit or otherwise)

What we know that it has processed 15 millions of flight plans previously without revealing this flaw. So they must have got some things right.