i found what you are looking for
you can download these and make your own version of the airport sounds like put them on a loop on an ipod or cd player. i am doing this to my airport aswell now im going to make a loop tape of garageband(apple mac) using atc aircraft sounds and departure halls
it has a cost but all you have to do is when in the preview button right click and say download linked file and it will give you the file without paying. which is one of the flaws with the design process of the website.
you will find tons of different sounds