My first digital was a Fuji Finepix which still works fine after 7 or 8 years. It was bought for photos for Ebay listings and was ideal for the job but I got really frustrated when I started going to airshows again and tried to take flying shots as it just doesn’t focus fast enough ( not even fast enough for a Bristol Boxkite at times) although more modern bridge cameras probably focus much faster.
I picked up a Canon EOS20D second hand on Ebay for £230. I am still learning to use it but am pleased with the results so far – any problems being down to operator error and not to the camera.
I know buying secondhand is a risk but at least you do get some comeback if you pay through paypal and the one I bought was only 30 mins drive away so I collected it rather than have it posted. If you buy from a dealer you will pay more but usually get at least some guarantee.
Mine came with a brand new standard zoom (18-55) which doesn’t seem to very popular with the reviewers in some of the camera mags but I can’t honestly say that I have had any problems with it.
The disadvantage is that until you can afford a bigger lens you won’t be able to do much in the way of flying shots but you will need a DSLR to have any chance of good flying shots and at least you will have taken the 1st step rather than buying a bridge camera which has no option to add a longer / better quality lens and will probably have lost most of its value when you come to sell and upgrade again.
I went with Canon because after 30+ years of using Canon film cameras I have always found them to be reliable and well built but the same principles apply to any of the major DSLR brands.
Whatever you decide to go with make sure you have a good look at all your options rather than rushing at the first thing that comes along.