PA44 ENTERING PATTERN AT HIO EXPERIENCED NMAC AT 1200 WITH SAME TYPE ACFT TURNING DOWNWIND; BLOCKED COM AND CTLR TRAINING CITED AS POSSIBLE CAUSE.

Narrative

CLASS D ARPT; WE HAD A CLOSE CALL WHILE TURNING TO JOIN THE DOWNWIND; THERE WAS ANOTHER ACFT ALSO MAKING THE TURN TO DOWNWIND FROM XWIND. WE PASSED TO THE L AND BELOW THEM. THERE WAS HVY RADIO CONGESTION AT THE TIME OF THE INCIDENT; THOUGH I BELIEVE TO HAVE BEEN INSTRUCTED TO JOIN AND RPT THE R DOWNWIND FOR THE RWY. AFTER SPEAKING WITH THE OTHER PLT AFTER THE INCIDENT THEY HAD BEEN EXPECTING US TO BE AHEAD AND TO THE L JOINING A BASE LEG FOR THE RWY. POSSIBLY A RADIO CALL WAS MISSED IN THIS TIME; THERE WERE MANY STEPPED ON/BLOCKED CALLS. TO SEE AND AVOID THE ACFT WE MADE A STEEP TURNING DSCNT; TAKING US THROUGH A HELI PATTERN AREA. WE CIRCLED; REJOINED THE DOWNWIND; AND WERE ABLE TO CONTACT TWR AGAIN. WE WERE MISIDENTED AT THIS POINT; AND AFTER A COUPLE RADIO CALLS THE PROB WAS SORTED OUT AND WE LANDED WITHOUT INCIDENT. AFTER POSTFLT BRIEFING WITH MY STUDENT I CALLED THE TWR TO TRY AND DETERMINE WHAT HAD OCCURRED. THE TWR SUPVR RPTED NO DEVS TO ME; AND WAS NOT EVEN AWARE OF THE NEAR COLLISION OR CIRCLING UNTIL I CALLED ON THE GND. AFTER A DISCUSSION WITH THE SUPVR THE PROB WAS ATTRIBUTED TO HVY RADIO CONGESTION; STEPPED ON/BLOCKED RADIO CALLS; AND A TRAINEE CTLR.