These are images of Russell Murens creation   of a coaxial helicoptor design using compressed air for power transmission.

Russell Muren, a Senior high school student at McNary High School in Oregon, designed this 23-part helicopter rotor blade system. The system runs off of compressed air and incorporates counter-rotating blades to decreases the need for a tail rotor. By rotating in opposite directions at the same speed each blade cancels out the other’s inertia and the overall inertia remains zero.