If there was no air on the earth, would air travel by aeroplanes, helicopters be possible?

If there were no air, flying machines like aeroplanes, helicopters etc would not be able to fly. The air and the design of the wings and propellers make it possible for these machines to fly. From Bernoulli's principle, the streamlined design of wings of the craft creates a difference of pressures above and below the wings. This creates an upward thrust that keeps the machine afloat and flying. 

So in the absence of air, there would be no upward thrust and these machines cannot fly in such a situation.