Narrative:

Class D airport; we had a close call while turning to join the downwind; there was another aircraft also making the turn to downwind from crosswind. We passed to the left and below them. There was heavy radio congestion at the time of the incident; though I believe to have been instructed to join and report the right downwind for the runway. After speaking with the other pilot after the incident they had been expecting us to be ahead and to the left joining a base leg for the runway. Possibly a radio call was missed in this time; there were many stepped on/blocked calls. To see and avoid the aircraft we made a steep turning descent; taking us through a helicopter pattern area. We circled; rejoined the downwind; and were able to contact tower again. We were misidented at this point; and after a couple radio calls the problem was sorted out and we landed without incident. After postflt briefing with my student I called the tower to try and determine what had occurred. The tower supervisor reported no deviations to me; and was not even aware of the near collision or circling until I called on the ground. After a discussion with the supervisor the problem was attributed to heavy radio congestion; stepped on/blocked radio calls; and a trainee controller.

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Original NASA ASRS Text

Title: 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.

Data retrieved from NASA's ASRS site as of May 2009 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.