PA28 PLT HAD AN NMAC AT AN UNCTLED ARPT.

Narrative

DURING PRACTICE EMER LNDGS AT DLZ ARPT; UPON TURNING TO A DOWNWIND POS; A WHITE/RED/GOLD STRIPED ARROW PA28 WAS SPOTTED COMING FROM CMH OR OSU; AT FULL SPD. AN IMMEDIATE DSCNT WAS INITIATED AS THE PROX WAS SURE ENOUGH TO CAUSE A COLLISION IN THE EVENT OF A TURN. I EXPECTED THE ACFT TO BE HIT AT THE VERT STABILIZER. WE FELT THE PROP WASH OF THE ACFT. THE OTHER PLT DID NOT APPEAR TO NOTICE. ALL APPROPRIATE CALLS HAD BEEN MADE ON THE DLZ UNICOM. THIS AREA IS A HIGH CONCENTRATION TRAINING AREA. NORMAL PROCS FOR TRAINING IN THIS AREA HAVE WORKED WELL. A CALL WAS MADE TO OSU TWR UPON LNDG TO ESTABLISH THE ORIGIN OF THE OTHER ACFT. IT WAS NOT RPTED AS COMING FROM OSU. HAD THIS ACFT COME FROM CMH; IT WOULD HAVE RECEIVED CAUTIONARY ADVISORY AS SEVERAL ACFT WERE IN THE AREA. THIS ACFT WAS IN HIGH SPD CRUISE AND DID NOT MAKE ANY TURNS AFTER THE INCIDENT; OR ANY ATTEMPT TO CALL ON THE UNICOM FREQ. I BELIEVE THE PLT STILL DOES NOT KNOW OF THE INCIDENT. ACKNOWLEDGEMENT IS MADE THAT BOTH ACFT ARE RESPONSIBLE FOR VFR SEPARATION; DESPITE OUR ALT EXCEEDING NORMAL TFC PATTERN ALT. APCHING ACFT HAVE MORE OF A RESPONSIBILITY TO LOOK OUT FOR ACFT/PARACHUTISTS; ETC.