CM
You make some fair points.
I am guessing that if you are going to div to FF then your TOD will be about 250nm west of London? - about 35 minutes from KK? At this range the anticipated arrival delay is becoming quite reliable, although perhaps slightly less so at Gatwick than Heathrow because KK is a mixed-mode operation and one can never be certain what departure demand will materialise (but early in the morning there is sure to be some).
Nonetheless, at 35 minutes from WILLO you would presumably know without doubt what your fuel would be at WILLO? Does it not follow that if at this point you are told that the delay will be 10 minutes, you must know for certain whether you have it covered or not? If the answer to that question is "no", then it must further follow that 35 minutes before you get to WILLO you know you are going to have to jump the queue to get in with destination fuel on board? To press on at that point, on the basis that the delay
may not materialise seems to me to be an unreasonable thing to do.
I have difficulty accepting that this crew didn't know they had less fuel than the reported delay at some considerable distance before WILLO. To me that suggests one thing - Divert. Unless, of course, you are permitted to burn your diversion fuel in the WILLO hold on the basis that a landing is assured? but at a single runway airport?
Is that logic correct?
.4