Many thanks to Mad (Flt) Sciemtist, BOAC and None for their responses to my question. I realize now it doesn't have a simple, straightforward answer.
M Scientist
I accept there can be a significant difference in the temperatures. However, am I right in believing that a T of -20 C at FL350 over the Equator would be exceptionally high and very rarely attained?
What would be a typical difference in T between Tropics and Arctic at FL350 on any given day?
None
I hope this isn't a stupid question but how well insulated from the outside air is the fuel in the tanks and lines? I mean, if the OAT is very low, does the fuel chill rapidly? From what you write, I guess it does.
Thanks in advance.
Rockhound