Narrative:

After departure, we climbed (on vectors) to our assigned altitude of 6000 ft on our way to the san marcus (rzs) VOR. Approximately 5-7 mi southeast of the VOR, we experienced light turbulence and a strong downdraft, causing a descent to approximately 5800 ft. Shortly thereafter, we experienced a significant updraft (and shift in wind direction) causing a 400 FPM climb. This took us to about 6300 ft, at which time I reported our altitude deviation to santa barbara approach and informed them that I was having trouble holding altitude due to the updraft. I pwred back to approximately 14 inches manifold pressure and 2200 RPM. The updraft and turbulence continued and I continued to climb to 7000 ft, which I also reported to santa barbara approach. I requested, and was given, vectors to rzs and away from the terrain near santa barbara. The turbulence and updraft abated, and allowed me to descend back to my assigned altitude of 6000 ft. Upon crossing the rzs VOR, I made a PIREP about the turbulence, windshear and strong up and downdrafts to los angeles flight watch. At no point during the event were we close enough to the terrain near rzs to have a problem with control. However, the closer we got to the terrain and the cumulus clouds in the area, the more severe the turbulence was. Neither the turbulence, the windshear, nor the broken-to-overcast clouds in the vicinity of the rzs VOR were forecast, so I was not initially prepared for them. I maintained control of the aircraft at all times, but was not able to abate the altdevs until I got out of the area of the strong up and downdrafts.

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Original NASA ASRS Text

Title: A C182 PLT EXPERIENCED TURB AT CRUISE, CAUSING VARIATIONS IN ALT.

Narrative: AFTER DEP, WE CLBED (ON VECTORS) TO OUR ASSIGNED ALT OF 6000 FT ON OUR WAY TO THE SAN MARCUS (RZS) VOR. APPROX 5-7 MI SE OF THE VOR, WE EXPERIENCED LIGHT TURB AND A STRONG DOWNDRAFT, CAUSING A DSCNT TO APPROX 5800 FT. SHORTLY THEREAFTER, WE EXPERIENCED A SIGNIFICANT UPDRAFT (AND SHIFT IN WIND DIRECTION) CAUSING A 400 FPM CLB. THIS TOOK US TO ABOUT 6300 FT, AT WHICH TIME I RPTED OUR ALTDEV TO SANTA BARBARA APCH AND INFORMED THEM THAT I WAS HAVING TROUBLE HOLDING ALT DUE TO THE UPDRAFT. I PWRED BACK TO APPROX 14 INCHES MANIFOLD PRESSURE AND 2200 RPM. THE UPDRAFT AND TURB CONTINUED AND I CONTINUED TO CLB TO 7000 FT, WHICH I ALSO RPTED TO SANTA BARBARA APCH. I REQUESTED, AND WAS GIVEN, VECTORS TO RZS AND AWAY FROM THE TERRAIN NEAR SANTA BARBARA. THE TURB AND UPDRAFT ABATED, AND ALLOWED ME TO DSND BACK TO MY ASSIGNED ALT OF 6000 FT. UPON XING THE RZS VOR, I MADE A PIREP ABOUT THE TURB, WINDSHEAR AND STRONG UP AND DOWNDRAFTS TO LOS ANGELES FLT WATCH. AT NO POINT DURING THE EVENT WERE WE CLOSE ENOUGH TO THE TERRAIN NEAR RZS TO HAVE A PROB WITH CTL. HOWEVER, THE CLOSER WE GOT TO THE TERRAIN AND THE CUMULUS CLOUDS IN THE AREA, THE MORE SEVERE THE TURB WAS. NEITHER THE TURB, THE WINDSHEAR, NOR THE BROKEN-TO-OVCST CLOUDS IN THE VICINITY OF THE RZS VOR WERE FORECAST, SO I WAS NOT INITIALLY PREPARED FOR THEM. I MAINTAINED CTL OF THE ACFT AT ALL TIMES, BUT WAS NOT ABLE TO ABATE THE ALTDEVS UNTIL I GOT OUT OF THE AREA OF THE STRONG UP AND DOWNDRAFTS.

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.