Here's a cool idea for anyone building the 1:48 scale Osprey from several years ago and displaying it on a runway/tarmack diorama.
Find two electric hobby motors for the model, these can be found at some Radio Shack stores and possibly HobbyLobby. While assembling the engine nacelles install a motor in each, run the wires through the wings and out through a small hole in the bottom of the fuselage and down into the base of the display. You can conceal the battery for powering the motors away from the display as you decide. When powered up, the rotors on this will actually start to lift the model off the display.
Feeder wires will have to be attached to the wires on the motors as these are never long enough for such applications. Also, hobby motors normally are rated for no more than 6-9 volts DC but this is suffciant to operate the rotors. The shafts on the electric motors can be fitted onto the rotors using empty Bic pen ink cartraiges,cut to about 1/4 of an inch long they make excellent adaptors for this sort of thing. Some extra fitting of these parts may be required but the results are worth the time.
johncpo