VH-BVJ was doing circuits and landings on runway 36. Because the light wind slightly favoured runway 05, the last landing was made on that runway. In order to vacate the runway after landing it was necessary to turn the aircraft around and backtrack. The crew of VH-BVJ then noticed that VH-AIR was lined up on runway 05. No radio calls had been received from VH-AIR. VH-AIR then commenced its takeoff towards VH-BVJ. The instructor in VH-BJV turned his aircraft left to vacate the runway and called to the pilot of VH-AIR to cut his engine. There was no response from VH-AIR, which continued its takeoff, passing abeam VH-BVJ about 10 feet above the ground. At this stage VH-BVJ had reached the edge of the bitumen runway but had not vacated onto the grass. Subsequently it was established that the radio in VH-AIR had been tuned 0.02 Mhz above the correct frequency. The pilot of VH-AIR saw VH-BVJ, apparently stationary on the northern end of the runway. Thinking the pilot of VH-BVJ had pulled over to the side of the runway to let him take off, he commenced his take-off roll. According to the pilot of VH-AIR, his aircraft passed abeam of VH-BVJ at a height of about 50 feet. Significant Factors The following factors were considered relevant to the development of the incident: 1. The pilot of VH-AIR had selected the incorrect radio frequency. 2. The pilot of VH-AIR took off on a runway that was occupied.