Two flights come to mind, re the fuel issue. Several years ago, on a full (362/362) L-1011 from LGW to YYZ. Scheduled as a non-stop, but extremely strong headwinds, plus heavily loaded ac, coupled with a very long take-off roll (it was a hot July day in London), caused the captain to announce midway through the flight that we would make an unsked stop in YUL to take on fuel. The flight had started in MAN, and I don't think they topped up the tanks at LGW.
The other flight was on CP, from LHR to YYZ, a B767, on Y2K day (remember that?) Total pax was 60 (according to the purser), and what should have been at most a seven and a 1/2 hour flight turned into over nine hours because of severe headwinds. Actually, at one point, the captain came on and said that even though we were flying at almost 600 mph, because of the headwinds we were barely making headway. No refueling stop, but I'm sure the fuel load was very light when we finally landed at YYZ.
Neither of these flights was on NWA, but I'm just trying to show what headwinds can do to even the most carefully planned flightplans and fuel loads.

bj-21.