Originally Posted by Globaliser

I am not an expert, but I suspect that the discussion is about conditions that are beyond the aircraft's certification limits or the airline's operating limits.

For example, there will be a tailwind limit laid down somewhere. If the tailwind exceeds that, then however skilled the pilot may personally be, it would be contrary to the safety philosophy of airlines to deliberately ignore the limits and operate beyond them.

Similarly, approach and landing accidents (which are often deadly) have been much reduced by strict inculcation of the need to fly a stable approach and to abandon it if it becomes unstable. But if the windshear conditions on the into-wind approach mean that most approaches will become destabilised, then it would again be utter foolishness for a pilot, however personally skilled, to ignore the principle that you abandon the approach - which could mean that landings would very often be impossible and the route therefore not viable.