Narrative:

I was on a solo flight from san carlos (sql) for practice maneuvering in an area east to north of byron (C83). I had leveled off to cruise at 5500 MSL and had contacted stockton approach while crossing livermore airport (lvk) for VFR radar advisories. I was advised to call again in two mins, but was called back shortly by the sck controller. I was given a squawk code and radar identified. Less than a minute later I made a turn right from heading 030 degrees to heading 045 degrees in order to pass south of byron airport. Just as I leveled out, I found myself directly head on to another aircraft closing at high speed at my altitude. I froze for a second or two, then immediately pulled up, but still felt like we were going to collide until the other aircraft pitched down and passed just under me. I made a left turn to try to get a look at and identify the other aircraft, and called stockton approach to report the near midair collision with a v-tail bonanza. Stockton approach reported that they had no secondary or primary radar targets in my area. Shouldn't it concern someone that aircraft can operate in this area so close to livermore labs without being picked up on primary radar? The point of near collision was 3 NM sse of altam intersection of V244 and V334. This is just outside the sfo mode C veil. The bonanza was apparently operating without a transponder within a few mins of entering an area requiring a mode C transponder. The bonanza was on a direct heading (225 degrees) probably for either hayward or san carlos airports and was at the wrong cruise altitude for VFR flight.

Google
 

Original NASA ASRS Text

Title: NMAC BETWEEN AN AC-112B AND A BE35 AT 5500 FT, OPPOSITE DIRECTION TFC 3 SSE OF ALTAM INTXN, ACFT X ON FREQ WITH APCH CTL AT SCK.

Narrative: I WAS ON A SOLO FLT FROM SAN CARLOS (SQL) FOR PRACTICE MANEUVERING IN AN AREA E TO N OF BYRON (C83). I HAD LEVELED OFF TO CRUISE AT 5500 MSL AND HAD CONTACTED STOCKTON APCH WHILE CROSSING LIVERMORE ARPT (LVK) FOR VFR RADAR ADVISORIES. I WAS ADVISED TO CALL AGAIN IN TWO MINS, BUT WAS CALLED BACK SHORTLY BY THE SCK CTLR. I WAS GIVEN A SQUAWK CODE AND RADAR IDENTIFIED. LESS THAN A MINUTE LATER I MADE A TURN R FROM HEADING 030 DEGS TO HEADING 045 DEGS IN ORDER TO PASS S OF BYRON ARPT. JUST AS I LEVELED OUT, I FOUND MYSELF DIRECTLY HEAD ON TO ANOTHER ACFT CLOSING AT HIGH SPEED AT MY ALTITUDE. I FROZE FOR A SECOND OR TWO, THEN IMMEDIATELY PULLED UP, BUT STILL FELT LIKE WE WERE GOING TO COLLIDE UNTIL THE OTHER ACFT PITCHED DOWN AND PASSED JUST UNDER ME. I MADE A LEFT TURN TO TRY TO GET A LOOK AT AND IDENTIFY THE OTHER ACFT, AND CALLED STOCKTON APCH TO REPORT THE NMAC WITH A V-TAIL BONANZA. STOCKTON APCH RPTED THAT THEY HAD NO SECONDARY OR PRIMARY RADAR TARGETS IN MY AREA. SHOULDN'T IT CONCERN SOMEONE THAT ACFT CAN OPERATE IN THIS AREA SO CLOSE TO LIVERMORE LABS WITHOUT BEING PICKED UP ON PRIMARY RADAR? THE POINT OF NEAR COLLISION WAS 3 NM SSE OF ALTAM INTERSECTION OF V244 AND V334. THIS IS JUST OUTSIDE THE SFO MODE C VEIL. THE BONANZA WAS APPARENTLY OPERATING WITHOUT A TRANSPONDER WITHIN A FEW MINS OF ENTERING AN AREA REQUIRING A MODE C TRANSPONDER. THE BONANZA WAS ON A DIRECT HEADING (225 DEGS) PROBABLY FOR EITHER HAYWARD OR SAN CARLOS ARPTS AND WAS AT THE WRONG CRUISE ALTITUDE FOR VFR FLT.

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.