Yes, they do.
If the UK is still in control of France at the Collect Income phase of the US.
This came up in a recent game. I took over Norway as Britain and later in the round the US player wanted to land his fighters there during his turn. However the German player objected, saying Britain hadn’t held the land for a full round yet so planes couldn’t land there.
The rules say “Bombers and fighters may land in any territory that
was friendly at the start of your turn.” I assume this means that particular player’s turn, not Britains turn, so the planes could land. Am I right on this?
You are right.
It cannot have been captured on your(US) Turn, then used.
Seems weird that the British can’t land there for the whole round but all their allies can. But I guess that’s the simplest way to play it out.
UK cannot land there because they did not own it at the beginning of their turn. US comes after them in the order.
You found the relevant rule and quoted it.