George Griffith's "Honeymoon In Space" hasn't been mentioned, which is a bit surprising. Aeronefs in that setting used the proven gravity-repelling powers of R-Matter (R for Repulsive of course). R-Matter is only found on Earth in meteor impact craters, which made holding such sites strategically important and further drove colonialism. The general effect was a "pusher" ray that could be aimed to provide both lift and (by angling the ray against the ground below) propulsion. It was quite capable of interplanetary travel as well as in-atmosphere maneuvering. The Chinese forces occupying the ex-USA in Armageddon 2419AD (the original Buck Rogers novel) used a very similar system for their airships, although their rays were produced by weird science generators rather than a relatively rare natural resource. They could also generate a tractor beam effect with a similar gadget, although the rebels quickly learned to use them against the Han by introducing bombs into the beam.