I like the idea of model airfields and have built a few myself over the years,these have varied from 1=200th Dinky Toy aircraft size to 1=72nd sections of airfields,I say sections as a complete full sized airfield in miniature would take up a lot of space ! take a tip out of the model railway community and why not build say a dispersal area,hangars and section of runways all as separate modules,this way they are compact and can be easily displayed alongside each other in diorama style.
Someone once asked me to put on an airfield display in a large hall,after a lot of thinking I came up with a compromise firstly laying a large sheet of green baize across some tables,then positioned various hangars,vehicles,control tower and crew together with the necessary aircraft,it looked very effective to visitors and was quickly dismantled at the end of the days show.
Another tip is to use smaller scale models in the background,this has an excellent scale effect against any skyline.
You can see sections of some of my diorama style mock ups for photographic model work in my diary pages,they were fun to put together and add extra interest to the subject matter.
Best of luck with your project and let us see the final results please,so take plenty of pictures during and after construction.