Narrative:

I was on an IFR flight from oak to wjf. Eventually, I was cleared to 11000 ft. 50 NM north of shafter, I began to pick up light rime icing. I checked the MEA/mora and requested lower. I was cleared to 9000 ft. Icing stopped but did not evaporate/sublimate. Outside air temperature was -1 degree C. I did not want to carry any ice over the ridge north of wjf, so I again checked MEA/mora and requested 7000 ft until shafter. I was given block clearance 7000-9000 ft and instructed to climb back to 9000 ft before 15 NM south of shafter. I descended to 7000 ft and the ice quickly cleared. At shafter, I climbed at 500 FPM back to 9000 ft. I let myself become a little distraction listening to a VFR pilot stuck above the layer over bakersfield and was shocked to discover light icing around the air intakes on both wings. I began fixating on the icing, although it was quite light. I was considering turning back to bfl when my airspeed plummeted. I visually checked the pitot tube and pulled the att static. I felt that it was windshear, but I was in IMC and did not want to trust my senses blindly. Mp and RPM indicated no change. I asked bfl approach about lower, and was told 9000 ft is MVA. They suggested joshua might be able to help. I switched to joshua, thinking that antelope valley should be close, but could not establish reliable communication. I was concerned that my high angle of attack would also create an icing risk, since more of the wing is potentially iced. Suddenly I was in moderate turbulence. Unable to hold altitude, I started a 180 degree turn. My thinking was that at least bfl could hear me and perhaps vector me to lower terrain. In the turn we broke into VMC and I immediately turned to a valley heading west. When the turbulence subsided, I descended to 5500 ft to maintain VFR separation from the cloud layer and explained to bfl what I was doing and asked for vectors to bfl. I reported the event as a microburst. At bfl I looked at radar and saw no cells, but I am convinced that the occurrence was either convective or a mountain wave from the ridge. No significant ice found from propeller or airframe after descending. But the real problem was judgement. I should have realized that my original plan was flawed. I knew that the weather might worsen on the ridge. That is why I wanted to start ice free. Making things worse was my fixation on individual events. It delayed my decision making worse. I lost situational awareness. I should have realized antelope valley was too far instead of taking the early handoff. Had I kept aware, instead of listening to someone else not looking for ice, I would have 180'd earlier, before the situation deteriorated.

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Original NASA ASRS Text

Title: A LOW TIME C182 PVT PLT RUNS INTO BAD WX CONDITIONS, PICKS UP ICING, RUNS INTO WINDSHEAR NEAR THE ANTELOPE VALLEY HILLS, HAS A SPD BLEED PROB AND DIVERTS FOR A PRECAUTIONARY LNDG AT BFL, CA.

Narrative: I WAS ON AN IFR FLT FROM OAK TO WJF. EVENTUALLY, I WAS CLRED TO 11000 FT. 50 NM N OF SHAFTER, I BEGAN TO PICK UP LIGHT RIME ICING. I CHKED THE MEA/MORA AND REQUESTED LOWER. I WAS CLRED TO 9000 FT. ICING STOPPED BUT DID NOT EVAPORATE/SUBLIMATE. OUTSIDE AIR TEMP WAS -1 DEG C. I DID NOT WANT TO CARRY ANY ICE OVER THE RIDGE N OF WJF, SO I AGAIN CHKED MEA/MORA AND REQUESTED 7000 FT UNTIL SHAFTER. I WAS GIVEN BLOCK CLRNC 7000-9000 FT AND INSTRUCTED TO CLB BACK TO 9000 FT BEFORE 15 NM S OF SHAFTER. I DSNDED TO 7000 FT AND THE ICE QUICKLY CLRED. AT SHAFTER, I CLBED AT 500 FPM BACK TO 9000 FT. I LET MYSELF BECOME A LITTLE DISTR LISTENING TO A VFR PLT STUCK ABOVE THE LAYER OVER BAKERSFIELD AND WAS SHOCKED TO DISCOVER LIGHT ICING AROUND THE AIR INTAKES ON BOTH WINGS. I BEGAN FIXATING ON THE ICING, ALTHOUGH IT WAS QUITE LIGHT. I WAS CONSIDERING TURNING BACK TO BFL WHEN MY AIRSPD PLUMMETED. I VISUALLY CHECKED THE PITOT TUBE AND PULLED THE ATT STATIC. I FELT THAT IT WAS WINDSHEAR, BUT I WAS IN IMC AND DID NOT WANT TO TRUST MY SENSES BLINDLY. MP AND RPM INDICATED NO CHANGE. I ASKED BFL APCH ABOUT LOWER, AND WAS TOLD 9000 FT IS MVA. THEY SUGGESTED JOSHUA MIGHT BE ABLE TO HELP. I SWITCHED TO JOSHUA, THINKING THAT ANTELOPE VALLEY SHOULD BE CLOSE, BUT COULD NOT ESTABLISH RELIABLE COM. I WAS CONCERNED THAT MY HIGH ANGLE OF ATTACK WOULD ALSO CREATE AN ICING RISK, SINCE MORE OF THE WING IS POTENTIALLY ICED. SUDDENLY I WAS IN MODERATE TURB. UNABLE TO HOLD ALT, I STARTED A 180 DEG TURN. MY THINKING WAS THAT AT LEAST BFL COULD HEAR ME AND PERHAPS VECTOR ME TO LOWER TERRAIN. IN THE TURN WE BROKE INTO VMC AND I IMMEDIATELY TURNED TO A VALLEY HEADING WEST. WHEN THE TURB SUBSIDED, I DSNDED TO 5500 FT TO MAINTAIN VFR SEPARATION FROM THE CLOUD LAYER AND EXPLAINED TO BFL WHAT I WAS DOING AND ASKED FOR VECTORS TO BFL. I REPORTED THE EVENT AS A MICROBURST. AT BFL I LOOKED AT RADAR AND SAW NO CELLS, BUT I AM CONVINCED THAT THE OCCURRENCE WAS EITHER CONVECTIVE OR A MOUNTAIN WAVE FROM THE RIDGE. NO SIGNIFICANT ICE FOUND FROM PROP OR AIRFRAME AFTER DSNDING. BUT THE REAL PROB WAS JUDGEMENT. I SHOULD HAVE REALIZED THAT MY ORIGINAL PLAN WAS FLAWED. I KNEW THAT THE WEATHER MIGHT WORSEN ON THE RIDGE. THAT IS WHY I WANTED TO START ICE FREE. MAKING THINGS WORSE WAS MY FIXATION ON INDIVIDUAL EVENTS. IT DELAYED MY DECISION MAKING WORSE. I LOST SITUATIONAL AWARENESS. I SHOULD HAVE REALIZED ANTELOPE VALLEY WAS TOO FAR INSTEAD OF TAKING THE EARLY HDOF. HAD I KEPT AWARE, INSTEAD OF LISTENING TO SOMEONE ELSE NOT LOOKING FOR ICE, I WOULD HAVE 180'D EARLIER, BEFORE THE SITUATION DETERIORATED.

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.