Originally Posted by
Seat3Dplease
This Junior Jet Club member remembers a 1967 flight from Montreal to London on a BOAC VC10 in 5 hours and small change. Pilot announced nobody had ever done it faster! Impossible to recover the details, I imagine.
That's good going - YUL-LHR is a tad further (Great Circle) than the later JFK-PIK record (5:01) set by the Super VC-10 in 1979.
But you have put your finger on the difficulty of establishing what the absolute shortest flight duration has been (assuming we're restricting ourselves to subsonic transatlantic regular scheduled services as our criteria).
The winner is almost certainly an instance of WestJet WS16, which operated from St John's (YYT) to Dublin in 2017-18. Its shortest flight time will likely have been significantly under 4 hours.
I'll do a bit of digging around to see if I can find out what that time was, but in the meantime if anyone has an unrestricted (business) subscription to FR24, which provides 2 years' worth of flight histories, it would be worth a look at WS16 there.