Went to Mumbai last Monday on BA 139- on takeoff, I was looking at the engines and noticed that the intakes filled with water vapour on spool-up, and this lasted until rotation.
I'd be interested to know what causes this, I haven't noticed it before.
Very nice flight, by the way, same goes for the return flight last Friday.
Finally, compliments of the season to all, especially those who post such interesting replies and info here. I've learned a lot since I've ben logging on here.