Narrative:

While proceeding from moffett field to crows landing, cruising at 400 KIAS, 11000' assigned, on IFR flight plan under ZOA. ZOA advised me of traffic at 12 O'clock less than 1 mi, an small aircraft Y, VFR at 10500'. I passed directly over small aircraft Y at what appeared to be 300' while the advisory was being transmitted. I advised the center that it was very close. After landing, I called oakland to discuss the incident. I was advised that the other aircraft had been advised previously of my position and had reported me in sight. I feel that the small aircraft Y pilot must have seen another aircraft. No pilot would allow another aircraft to pass that close (and fast) west/O taking evasive action. I was on an easterly heading toward the sun and had a poor chance of seeing the other aircraft. The center admitted that a collision warning had sounded ay 5 mi, but I was not advised because the controller was too busy. The advisory issued to the other aircraft was on another frequency. I feel that the center was negligent in allowing two aircraft under their control (even though one was VFR) to come that close. Especially when a collision alert had sounded. Neither aircraft had the chance to take evasive action.

Google
 

Original NASA ASRS Text

Title: FGT AND SMA NMAC.

Narrative: WHILE PROCEEDING FROM MOFFETT FIELD TO CROWS LNDG, CRUISING AT 400 KIAS, 11000' ASSIGNED, ON IFR FLT PLAN UNDER ZOA. ZOA ADVISED ME OF TFC AT 12 O'CLOCK LESS THAN 1 MI, AN SMA Y, VFR AT 10500'. I PASSED DIRECTLY OVER SMA Y AT WHAT APPEARED TO BE 300' WHILE THE ADVISORY WAS BEING XMITTED. I ADVISED THE CTR THAT IT WAS VERY CLOSE. AFTER LNDG, I CALLED OAKLAND TO DISCUSS THE INCIDENT. I WAS ADVISED THAT THE OTHER ACFT HAD BEEN ADVISED PREVIOUSLY OF MY POS AND HAD RPTED ME IN SIGHT. I FEEL THAT THE SMA Y PLT MUST HAVE SEEN ANOTHER ACFT. NO PLT WOULD ALLOW ANOTHER ACFT TO PASS THAT CLOSE (AND FAST) W/O TAKING EVASIVE ACTION. I WAS ON AN EASTERLY HDG TOWARD THE SUN AND HAD A POOR CHANCE OF SEEING THE OTHER ACFT. THE CTR ADMITTED THAT A COLLISION WARNING HAD SOUNDED AY 5 MI, BUT I WAS NOT ADVISED BECAUSE THE CTLR WAS TOO BUSY. THE ADVISORY ISSUED TO THE OTHER ACFT WAS ON ANOTHER FREQ. I FEEL THAT THE CTR WAS NEGLIGENT IN ALLOWING TWO ACFT UNDER THEIR CTL (EVEN THOUGH ONE WAS VFR) TO COME THAT CLOSE. ESPECIALLY WHEN A COLLISION ALERT HAD SOUNDED. NEITHER ACFT HAD THE CHANCE TO TAKE EVASIVE ACTION.

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.