Narrative:

I was cleared through sfo class B airspace, own navigation. I thought I might have heard a course change ordered, but radio was scratchy. I called bay approach to clarify if I was given a course change. Frequency was very busy, and the only response I heard for me was a callout of traffic. I saw the traffic, there was no conflict that I could see. When I told approach control that I saw the traffic and that it was passing me with no problem, I was notified that I had been given a course change because of that traffic. The other traffic may have been held at a lower altitude to pass me, though I don't know this. When the controller responded to my original query (about a missed course change) with a traffic callout, I assumed that either there was no course deviation ordered or that I was authority/authorized to stay clear of the traffic, since I was VFR and both planes were in VMC. I think that maybe the controller didn't hear my query about a possible instruction from him about course change, as the frequency was very busy. I should have insisted on a clear answer to my query about a possible ATC instruction, even with crowded frequency and other instructions given to me by controller.

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Original NASA ASRS Text

Title: BE24 PLT TRANSITING CLASS B AIRSPACE HAS CLRNC PROB AND DOES NOT PICK UP A VECTOR ISSUED BY APCH.

Narrative: I WAS CLRED THROUGH SFO CLASS B AIRSPACE, OWN NAV. I THOUGHT I MIGHT HAVE HEARD A COURSE CHANGE ORDERED, BUT RADIO WAS SCRATCHY. I CALLED BAY APCH TO CLARIFY IF I WAS GIVEN A COURSE CHANGE. FREQ WAS VERY BUSY, AND THE ONLY RESPONSE I HEARD FOR ME WAS A CALLOUT OF TFC. I SAW THE TFC, THERE WAS NO CONFLICT THAT I COULD SEE. WHEN I TOLD APCH CTL THAT I SAW THE TFC AND THAT IT WAS PASSING ME WITH NO PROB, I WAS NOTIFIED THAT I HAD BEEN GIVEN A COURSE CHANGE BECAUSE OF THAT TFC. THE OTHER TFC MAY HAVE BEEN HELD AT A LOWER ALT TO PASS ME, THOUGH I DON'T KNOW THIS. WHEN THE CTLR RESPONDED TO MY ORIGINAL QUERY (ABOUT A MISSED COURSE CHANGE) WITH A TFC CALLOUT, I ASSUMED THAT EITHER THERE WAS NO COURSE DEV ORDERED OR THAT I WAS AUTH TO STAY CLR OF THE TFC, SINCE I WAS VFR AND BOTH PLANES WERE IN VMC. I THINK THAT MAYBE THE CTLR DIDN'T HEAR MY QUERY ABOUT A POSSIBLE INSTRUCTION FROM HIM ABOUT COURSE CHANGE, AS THE FREQ WAS VERY BUSY. I SHOULD HAVE INSISTED ON A CLR ANSWER TO MY QUERY ABOUT A POSSIBLE ATC INSTRUCTION, EVEN WITH CROWDED FREQ AND OTHER INSTRUCTIONS GIVEN TO ME BY CTLR.

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.