You could easily start with AdSense ads, establish your ad locations, and look at contacting aviation firms once you had some idea of what your stats are (and perhaps therefore what your pricing would be). Or there are PPC servers/services and you might add them to your site (doubt they are 'free' though --- we run our own ad server using a 3rd party package ... we got a lifetime license so it's getting "cheaper" every month it continues to run...)
Steve R Jones wrote:Depending on your membership levels and page hits etc - getting some aviation companies to advertise is something to consider... Course, if you think you're putting in a lot of time now - it'll get worse
Yup to that.
You might also look into affiliate marketing of category-related products, but that IS a lot of work, and some of the services make it really difficult to convert for certain categories of products (in particular, some of them set their cookie timeout very low, which means that any product for which a consumer is likely to think for a day before purchasing won't earn you a commission).