I'd never heard of that either, BBB, and I flew on my first commercial flight as a pax in 1959 and many, many more in all types of weather since then. But it's true and we (my wife and I) can only repeat what the captain of our B777-200 announced as the reason for the delay. We did have a very cold, snowy (the most this year to that date, per the Weather Channel) day where the snow had started the early in the morning of our departure, and continued right up to our departure time of 6:30 PM, on BA 92, YYZ-LHR.

So the inbound flight from LHR had landed here in the heavy snow and very cold, windy temperatures (how long is the usual turnaround times for those flights, isn't it usually two or three hours on the ground?). And I thought that the contents of those tanks would have prevented them from freezing, but..!

Papi, considering all the tanks from the eight or so lavs and what they were holding, I'd say that 45 minutes for the turdaround may have been record time.

bj-21.