The idea is pinched from Simon Miller's "Crimson Bat" model for Gloranthan Hordes of the Things. Basically it's a foamcore and card model based on a CD. The building contains a few dozen unwanted lead figures and a load of tile grout to give it some stability.
The chimney extends into a variable height flying stand that's made from one of those extendible magnet things - like a car aerial and designed to pick up metal objects from inaccessible spaces.
Each of my aircraft has a small magnetic coin glued to its underside (I use Latvian 1 Santims pieces but modern British pennies will do the job too). This allows you to mount the aircraft securely on the stand at any appropriate height from about 15 to 60 centimetres.
This final pic shows an Andreivian Air Force A4 Skyhawk flying low over a typical Andreivian house.
When I get some better pics done this will be my entry to The Guild's scenery group build.