[j_mo]

No validation, anddd this point from the article stood out to me: --- The programming style is very imperative. Furthermore, the description sounds like the procedure is working directly on the textual representation of the flight plan, rather than a data structure parsed from the text file. This would be quite worrying, but it might also just be how it is explained. --- Given that description, I'd be surprised if it wasn't just running a regex / substring matches against the text and there's no classes / objects / data structure involved. Bearing in mind this is likely decades old C code that can't be rewritten or replaced because the entirety of the UK's aviation runs on it.

[jameshh]

> Bearing in mind this is likely decades old C code that can't be rewritten or replaced because the entirety of the UK's aviation runs on it.

It's new code, from 2018 :) Quote from the report:

> An FPRSA sub-system has existed in NATS for many years and in 2018 the previous FPRSA sub- system was replaced with new hardware and software manufactured by Frequentis AG, one of the leading global ATC System providers.