Narrative:

I was shooting touch and go's in an small aircraft a right pattern, 30R, sjc. As I remember it, the tower said an small aircraft B was landing on the left runway and I was 'cleared for the option.' I have a very strong memory of the clearance. I was downwind abeam of the tower. I flew a short pattern well inside highway 880. As I rolled out to final I saw the small aircraft B at about the above distance. In a later phone conversation with the tower personnel they claimed that I was told to follow the small aircraft B. I heard no xmissions between the tower and small aircraft B during or after his landing and I believe that he was on 124.0, the frequency for 30L. I definitely did not hear him being cleared to land. I think it is most likely that he was on approach to 30L, but was switched to the right runway and remained on the original frequency. This is common for light aircraft at sjc. The tower supervisor has promised to review the tapes and to try and reconstruct the events. If indeed I was told to follow the small aircraft B, it appears unsafe to give me a landing clearance while I was on downwind. That procedure should be changed. The fact that 2 frequencys are used does not allow the other pilot to be aware of a second landing clearance to his runway when one aircraft has a runway switched but remains on the original frequency. Since I had to fly 1/2-3/4 mi on base this was warning time. The tower was extremely slow in responding to the converging situation. On the other hand I should have been visually scanning the area even though I was in the pattern and I should have seen the small aircraft B.

Related reports:

Google
 

Original NASA ASRS Text

Title: SMA DOING PATTERN WORK HAS NMAC WITH SMA ON APCH TO SAME RWY, NOT ON SAME FREQ.

Narrative: I WAS SHOOTING TOUCH AND GO'S IN AN SMA A RIGHT PATTERN, 30R, SJC. AS I REMEMBER IT, THE TWR SAID AN SMA B WAS LNDG ON THE LEFT RWY AND I WAS 'CLRED FOR THE OPTION.' I HAVE A VERY STRONG MEMORY OF THE CLRNC. I WAS DOWNWIND ABEAM OF THE TWR. I FLEW A SHORT PATTERN WELL INSIDE HWY 880. AS I ROLLED OUT TO FINAL I SAW THE SMA B AT ABOUT THE ABOVE DISTANCE. IN A LATER PHONE CONVERSATION WITH THE TWR PERSONNEL THEY CLAIMED THAT I WAS TOLD TO FOLLOW THE SMA B. I HEARD NO XMISSIONS BTWN THE TWR AND SMA B DURING OR AFTER HIS LNDG AND I BELIEVE THAT HE WAS ON 124.0, THE FREQ FOR 30L. I DEFINITELY DID NOT HEAR HIM BEING CLRED TO LAND. I THINK IT IS MOST LIKELY THAT HE WAS ON APCH TO 30L, BUT WAS SWITCHED TO THE RIGHT RWY AND REMAINED ON THE ORIGINAL FREQ. THIS IS COMMON FOR LIGHT ACFT AT SJC. THE TWR SUPVR HAS PROMISED TO REVIEW THE TAPES AND TO TRY AND RECONSTRUCT THE EVENTS. IF INDEED I WAS TOLD TO FOLLOW THE SMA B, IT APPEARS UNSAFE TO GIVE ME A LNDG CLRNC WHILE I WAS ON DOWNWIND. THAT PROC SHOULD BE CHANGED. THE FACT THAT 2 FREQS ARE USED DOES NOT ALLOW THE OTHER PLT TO BE AWARE OF A SECOND LNDG CLRNC TO HIS RWY WHEN ONE ACFT HAS A RWY SWITCHED BUT REMAINS ON THE ORIGINAL FREQ. SINCE I HAD TO FLY 1/2-3/4 MI ON BASE THIS WAS WARNING TIME. THE TWR WAS EXTREMELY SLOW IN RESPONDING TO THE CONVERGING SITUATION. ON THE OTHER HAND I SHOULD HAVE BEEN VISUALLY SCANNING THE AREA EVEN THOUGH I WAS IN THE PATTERN AND I SHOULD HAVE SEEN THE SMA B.

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.