Narrative:

Upon contacting tower, we were told to report a 2 mi right 45 degree entry for runway 21. Neither the student nor I recall hearing the left or right runway (prc has runway 21L&right separated by 700 ft). We entered a wide right downwind per tower instructions. I had failed one of the engines (simulated) by reducing the throttle to idle at about 4 mi from the airport. We advised tower that we had traffic off our right wing in sight on a closer downwind and they gave us landing clearance. I recall reading back 'cleared to land runway 21L.' we lost sight of our traffic to follow when on base leg after we extended the downwind leg a couple of mi. I advised the tower and asked for an update on our traffic's position. They never got back to me. Unknown to me at the time, there was a bonanza reporting smoke in the cockpit nearby that had declared an emergency. The tower frequency was saturated. Several aircraft were instructed to circle at various points around the pattern. Just as I was about to key the microphone to confirm landing clearance, we noticed another aircraft to our left, high. We were going faster than the other airplane and were slightly ahead of them. This was on about a 1 mi final. I took the controls from the student and applied full power. At the same time, I increased our rate of descent to increase our lateral and vertical distance from the other aircraft. The other aircraft did not appear to be taking any evasive action. We were in their blind spot. It is worth noting that the tower was using 2 frequencys at the time. We were on the frequency for aircraft arriving from the southwest. The other aircraft was on the other frequency. After we were well ahead of the other aircraft, I initiated a go around. At that time, the tower asked us which runway we were lined up for. I told them runway 21L. They then instructed us to go around. I advised them that we were already doing that. I believe this situation occurred because of lack of adequate communications regarding pattern entry and landing clearance. Saturation of the pattern, an emergency in progress and lack of questioning of ATC instructions earlier contributed. A similar situation could be prevented by being more aware of potential miscom in the future on the part of the controller and the pilot.

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Original NASA ASRS Text

Title: A BE76 AND A CHEROKEE HAVE AN NMAC WHILE BOTH ACFT ARE APCHING RWY 21L AT PRC, AZ.

Narrative: UPON CONTACTING TWR, WE WERE TOLD TO RPT A 2 MI R 45 DEG ENTRY FOR RWY 21. NEITHER THE STUDENT NOR I RECALL HEARING THE L OR R RWY (PRC HAS RWY 21L&R SEPARATED BY 700 FT). WE ENTERED A WIDE R DOWNWIND PER TWR INSTRUCTIONS. I HAD FAILED ONE OF THE ENGS (SIMULATED) BY REDUCING THE THROTTLE TO IDLE AT ABOUT 4 MI FROM THE ARPT. WE ADVISED TWR THAT WE HAD TFC OFF OUR R WING IN SIGHT ON A CLOSER DOWNWIND AND THEY GAVE US LNDG CLRNC. I RECALL READING BACK 'CLRED TO LAND RWY 21L.' WE LOST SIGHT OF OUR TFC TO FOLLOW WHEN ON BASE LEG AFTER WE EXTENDED THE DOWNWIND LEG A COUPLE OF MI. I ADVISED THE TWR AND ASKED FOR AN UPDATE ON OUR TFC'S POS. THEY NEVER GOT BACK TO ME. UNKNOWN TO ME AT THE TIME, THERE WAS A BONANZA RPTING SMOKE IN THE COCKPIT NEARBY THAT HAD DECLARED AN EMER. THE TWR FREQ WAS SATURATED. SEVERAL ACFT WERE INSTRUCTED TO CIRCLE AT VARIOUS POINTS AROUND THE PATTERN. JUST AS I WAS ABOUT TO KEY THE MIKE TO CONFIRM LNDG CLRNC, WE NOTICED ANOTHER ACFT TO OUR L, HIGH. WE WERE GOING FASTER THAN THE OTHER AIRPLANE AND WERE SLIGHTLY AHEAD OF THEM. THIS WAS ON ABOUT A 1 MI FINAL. I TOOK THE CTLS FROM THE STUDENT AND APPLIED FULL PWR. AT THE SAME TIME, I INCREASED OUR RATE OF DSCNT TO INCREASE OUR LATERAL AND VERT DISTANCE FROM THE OTHER ACFT. THE OTHER ACFT DID NOT APPEAR TO BE TAKING ANY EVASIVE ACTION. WE WERE IN THEIR BLIND SPOT. IT IS WORTH NOTING THAT THE TWR WAS USING 2 FREQS AT THE TIME. WE WERE ON THE FREQ FOR ACFT ARRIVING FROM THE SW. THE OTHER ACFT WAS ON THE OTHER FREQ. AFTER WE WERE WELL AHEAD OF THE OTHER ACFT, I INITIATED A GAR. AT THAT TIME, THE TWR ASKED US WHICH RWY WE WERE LINED UP FOR. I TOLD THEM RWY 21L. THEY THEN INSTRUCTED US TO GO AROUND. I ADVISED THEM THAT WE WERE ALREADY DOING THAT. I BELIEVE THIS SIT OCCURRED BECAUSE OF LACK OF ADEQUATE COMS REGARDING PATTERN ENTRY AND LNDG CLRNC. SATURATION OF THE PATTERN, AN EMER IN PROGRESS AND LACK OF QUESTIONING OF ATC INSTRUCTIONS EARLIER CONTRIBUTED. A SIMILAR SIT COULD BE PREVENTED BY BEING MORE AWARE OF POTENTIAL MISCOM IN THE FUTURE ON THE PART OF THE CTLR AND THE PLT.

Data retrieved from NASA's ASRS site as of July 2007 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.