It really did look like it was flying through the air.
That's because, in a sense, it was. For those two really iconic shots of the craft swooping past the Trona Pinnacles located in Death Valley, the effects team employed a technique developed by the Lydecker Brothers. The miniature, I assume the two foot version, slid along a set of wires positioned a bit off from horizontal, one end positioned higher than the other, on location in Death Valley. That way, whatever light illuminated the rock formations also lit the model.
This method was also used in the Commando Cody Saturday matinee serials. A "doll" dressed the same as the actor was filmed outdoors, sliding upon the wire arrangement described above.
Sincerely,
Bill
