Well, "it" the software did not decide (that would be AI
), the designers / specifiers did.
Likely a question for eglynt, the FPRSA-R seems to be planned on falling over, since there is manual input system. Can the 2 work alongside each other? i.e. could the FPRSA-R throw up an error message (rather than full exception) saying "I cannot deal with Flt Plan XYZ, meanwhile I will carry on". The an ATCO can get Flt Plan XYZ and manually input it.
Martin Rolfe seems keen to say this has never happened before in 15 million flights. Someone inclined to believe him might understand that to mean it has flawlessly processed every Flt Plan since 2018 without a single hiccup. From this thread, it seems it has always been temperamental, just the 4 hour buffer has, to date proved adequate to solve the issue.
(p9) looks forward through flight to identify UK entry point. Then goes to end of whole route and works back to find UK exit point, which it could not find because it was not (no need for it to be) specified. It then looked for points near to UK airspace to try and work out an exit - but seems it found the duplicate name point and picked the wrong one, and now
"the software could not extract a valid UK portion of flight plan between these two points" at which point it threw a wobbly.
I am not entirely convinced by "
However, since flight data is safety critical information that is passed to ATCOs the system must be sure it is correct and could not do so in this case. It therefore stopped operating, avoiding any opportunity for incorrect data being passed to a controller. The change to the software will now remove the need for a critical exception to be raised in these specific circumstances." - since the software correctly identified the dodgy Flt Plan, and could just not have passed it on, letting someone manually do it.
My guess is this now becomes the work of spin doctors who can only state "safety - worked as designed" and will require leaks from inside NATS as to how "wonderful" FPRSA-R really was, and whether MR is speaking the truth in that it had never got confused or stopped since 2018?? If it was temperamental, requiring manual interventions, then how these were reported investigated solved would be interesting...