Narrative:

While climbing out of smo for L35 I was in contact with socal approach, burbank facility, obtaining RA's on 135.05. The controller had called out to me air carrier traffic at my 12 O'clock position. I saw some lights in the distance and assumed that that was my traffic and called 'contact.' while continuing my climb out of 6000 ft the controller again called out traffic at my 12 O'clock position. I again looked for the opposite direction traffic and had lost sight of it. I then heard the other aircraft say that I was picked up on his TCASII. Before I could say that I had lost sight of the aircraft, the controller asked me to turn right to 110 degrees. I looked at my heading indicator and it showed 090 degrees. (The heading indicator slaved to a remote compass that up until now had been relatively trouble free.) I was flying along a route that I am familiar with and was conducting the flight by visual flight references. I had not been flying by reference to my instruments and had not noticed that my heading indicator had precessed and that the slaving system was not functioning properly. I figured out later by reference to my wet compass that the heading indicator should have been reading 060 degrees and not 090 degrees. When the controller asked for a turn to 110 degrees I made a 20 degree turn to the right. The commercial aircraft passed well off to my left at a distance of 3000 ft to 5000 ft and was approximately 750-1000 ft below me. After the commercial carrier passed the controller asked why I didn't make the turn to 110 degrees. I responded by saying that I did. I was later advised to call the approach facility to discuss the situation. I was informed that the other pilot felt the need to make a rapid descent to avoid a conflict. This situation could have been avoided if I were more vigilant about xrefing my heading indicator with my compass even in VFR conditions and immediately telling the controller when I lose traffic that I had had a prior visual on. It also would have been helpful if the controller had asked me to 'say heading' prior to giving me the turn.

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Original NASA ASRS Text

Title: A C340 ATP PLT HAS A POTENTIAL CONFLICT WITH AN OPPOSITE DIRECTION ACR WHEN CLBING VFR THROUGH ITS ALT 15 MI W OF POM, CA.

Narrative: WHILE CLBING OUT OF SMO FOR L35 I WAS IN CONTACT WITH SOCAL APCH, BURBANK FACILITY, OBTAINING RA'S ON 135.05. THE CTLR HAD CALLED OUT TO ME ACR TFC AT MY 12 O'CLOCK POS. I SAW SOME LIGHTS IN THE DISTANCE AND ASSUMED THAT THAT WAS MY TFC AND CALLED 'CONTACT.' WHILE CONTINUING MY CLB OUT OF 6000 FT THE CTLR AGAIN CALLED OUT TFC AT MY 12 O'CLOCK POS. I AGAIN LOOKED FOR THE OPPOSITE DIRECTION TFC AND HAD LOST SIGHT OF IT. I THEN HEARD THE OTHER ACFT SAY THAT I WAS PICKED UP ON HIS TCASII. BEFORE I COULD SAY THAT I HAD LOST SIGHT OF THE ACFT, THE CTLR ASKED ME TO TURN R TO 110 DEGS. I LOOKED AT MY HEADING INDICATOR AND IT SHOWED 090 DEGS. (THE HEADING INDICATOR SLAVED TO A REMOTE COMPASS THAT UP UNTIL NOW HAD BEEN RELATIVELY TROUBLE FREE.) I WAS FLYING ALONG A RTE THAT I AM FAMILIAR WITH AND WAS CONDUCTING THE FLT BY VISUAL FLT REFS. I HAD NOT BEEN FLYING BY REF TO MY INSTS AND HAD NOT NOTICED THAT MY HEADING INDICATOR HAD PRECESSED AND THAT THE SLAVING SYS WAS NOT FUNCTIONING PROPERLY. I FIGURED OUT LATER BY REF TO MY WET COMPASS THAT THE HEADING INDICATOR SHOULD HAVE BEEN READING 060 DEGS AND NOT 090 DEGS. WHEN THE CTLR ASKED FOR A TURN TO 110 DEGS I MADE A 20 DEG TURN TO THE R. THE COMMERCIAL ACFT PASSED WELL OFF TO MY L AT A DISTANCE OF 3000 FT TO 5000 FT AND WAS APPROX 750-1000 FT BELOW ME. AFTER THE COMMERCIAL CARRIER PASSED THE CTLR ASKED WHY I DIDN'T MAKE THE TURN TO 110 DEGS. I RESPONDED BY SAYING THAT I DID. I WAS LATER ADVISED TO CALL THE APCH FACILITY TO DISCUSS THE SIT. I WAS INFORMED THAT THE OTHER PLT FELT THE NEED TO MAKE A RAPID DSCNT TO AVOID A CONFLICT. THIS SIT COULD HAVE BEEN AVOIDED IF I WERE MORE VIGILANT ABOUT XREFING MY HEADING INDICATOR WITH MY COMPASS EVEN IN VFR CONDITIONS AND IMMEDIATELY TELLING THE CTLR WHEN I LOSE TFC THAT I HAD HAD A PRIOR VISUAL ON. IT ALSO WOULD HAVE BEEN HELPFUL IF THE CTLR HAD ASKED ME TO 'SAY HEADING' PRIOR TO GIVING ME THE TURN.

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.