Lense choice ?

Do you have any sunny days over there at this time of year? The only othermarks on the 80-200mm lens are 1:4.5-5.6 II

Just my €0,02 worth but I’d leave the 80-200 at home, unless it offers more light compared to the 75-300 lens. With the 28-80 and the 75-300 you’ve got the whole spectrum covered so why carry around an extra lens? Now if the 80-200 is a F2.8 lens then it’s a different story but still you could argue that if you’re going to be using it on sunny days the 75-300 will probably be sufficient and offer more magnification.

I haven’t been to Hendon for donkey’s years, but I believe that you have to ask permission to use a tripod there. The other aircraft places you mention are no problem, and at Duxford you might get some flying shots if you are lucky.
You can see some of my Duxford pictures here:
http://www.planesandchoppers.com/list.asp?field=contributor_no&crit=93
Have a good trip!

Thank you again for the advice , I hope to visit Hendon , Duxford , Old Warden , Bruntingthorpe and Cumbria for a wedding .

In museums I use a tripod whenever possible, only using flash if tripods are not permitted, but the results usually require a lot of photoshopping afterwards as you must have a long depth of field (see the camera manual information about “aperture”). I have an EOS 350D which works just fine for almost every situation, but I’m just an amateur! There are other people on this Forum who are experts, and I guess they will soon post some helpful comments for you.
Just remember that as long as you have enough memory in the camera, you can experiment with different apertures and times to find what suits the situation best. I discard about 90% of my pictures when they have been taken in tricky lighting situations, but I suppose I am a slow learner!
One very difficult museum in my opinion is the USAF Museum at Wright-Patterson, Dayton, very dark with only spotlights at ceiling level (a high ceiling too) – but they do permit tripods!

That was quick thank you , the camera is a Canon EOS 500 N , it has a built in flash will this be adequate or would it be better to get a flash as an accessory ?

I would take all three, using the short lens in museums, the middle one for medium distance shots of aircraft, etc. on the ground, and the long one for aircraft that are flying.