Hi All, new here & first post, so go easy on me!

, just a few questions about use of filters for aviation photography.
I've been snapping for a good few years now, but not much aircraft (RIAT '05 & a few Portrush & Ards shows) & was wondering if use of a polarising filter (sunny days) be helpful for both reducing glare from windows etc. and darkening the blue of the sky (depending obviously on the angle to the sun).
would anyone use this or is it not worth the loss of f-stops?
Thanks,
Joe