Narrative:

During taxi I performed the autoplt test followed by the electric trim test, both of which were completed normally. On departure (VMC) I attempted to engage the autoplt, but only the yaw damper would engage. I briefly thought about turning around and landing again -- which would have been the correct and conservative decision. However, I decided to press on, and next was confronted by having to maneuver around some WX. Approach cleared me to deviate as needed, but the path directly ahead looked good on my onboard radar, a swath of green between red on my right and left. I mentioned this to ATC, who said everyone else had been deviating, but I decided it was ok ahead. In fact it was, but we did encounter some brief heavy rain and some intermittent moderate turbulence. We saw no nearby lighting, with the nearest being perhaps 10 mi on my left. But what was I thinking? If I hadn't been trying to get the autoplt back on line, I probably would have deviated around the area anyway. There was really no reason not to, and to be honest, it was significantly worse than I would have thought based on the image painted on my radar, and a turn to the right would have put me in near VMC. On climb out passing about FL200 in VMC, the autoplt started to work again, and worked flawlessly the rest of the flight. Lessons: 1) although probably legal, it was a very poor decision not to immediately return to the departure airport to correct the autoplt problem (this was later demonstrated to be a repeatable, and due to a dirty relay), 2) I need better/recurrent instruction in interpretation of onboard radar. I'm used to flying with not only radar, but also with a lightning detector as well as up-linked 'nexrad' images on a WX radar system, and I think that my basic radar skills have deteriorated. I'm going to dig out the WX radar training tapes again before my next flight.

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Original NASA ASRS Text

Title: C501 PLT ENCOUNTERED MODERATE TURB AND HVY RAIN FROM TSTM.

Narrative: DURING TAXI I PERFORMED THE AUTOPLT TEST FOLLOWED BY THE ELECTRIC TRIM TEST, BOTH OF WHICH WERE COMPLETED NORMALLY. ON DEP (VMC) I ATTEMPTED TO ENGAGE THE AUTOPLT, BUT ONLY THE YAW DAMPER WOULD ENGAGE. I BRIEFLY THOUGHT ABOUT TURNING AROUND AND LNDG AGAIN -- WHICH WOULD HAVE BEEN THE CORRECT AND CONSERVATIVE DECISION. HOWEVER, I DECIDED TO PRESS ON, AND NEXT WAS CONFRONTED BY HAVING TO MANEUVER AROUND SOME WX. APCH CLRED ME TO DEVIATE AS NEEDED, BUT THE PATH DIRECTLY AHEAD LOOKED GOOD ON MY ONBOARD RADAR, A SWATH OF GREEN BTWN RED ON MY R AND L. I MENTIONED THIS TO ATC, WHO SAID EVERYONE ELSE HAD BEEN DEVIATING, BUT I DECIDED IT WAS OK AHEAD. IN FACT IT WAS, BUT WE DID ENCOUNTER SOME BRIEF HVY RAIN AND SOME INTERMITTENT MODERATE TURB. WE SAW NO NEARBY LIGHTING, WITH THE NEAREST BEING PERHAPS 10 MI ON MY L. BUT WHAT WAS I THINKING? IF I HADN'T BEEN TRYING TO GET THE AUTOPLT BACK ON LINE, I PROBABLY WOULD HAVE DEVIATED AROUND THE AREA ANYWAY. THERE WAS REALLY NO REASON NOT TO, AND TO BE HONEST, IT WAS SIGNIFICANTLY WORSE THAN I WOULD HAVE THOUGHT BASED ON THE IMAGE PAINTED ON MY RADAR, AND A TURN TO THE R WOULD HAVE PUT ME IN NEAR VMC. ON CLBOUT PASSING ABOUT FL200 IN VMC, THE AUTOPLT STARTED TO WORK AGAIN, AND WORKED FLAWLESSLY THE REST OF THE FLT. LESSONS: 1) ALTHOUGH PROBABLY LEGAL, IT WAS A VERY POOR DECISION NOT TO IMMEDIATELY RETURN TO THE DEP ARPT TO CORRECT THE AUTOPLT PROB (THIS WAS LATER DEMONSTRATED TO BE A REPEATABLE, AND DUE TO A DIRTY RELAY), 2) I NEED BETTER/RECURRENT INSTRUCTION IN INTERP OF ONBOARD RADAR. I'M USED TO FLYING WITH NOT ONLY RADAR, BUT ALSO WITH A LIGHTNING DETECTOR AS WELL AS UP-LINKED 'NEXRAD' IMAGES ON A WX RADAR SYS, AND I THINK THAT MY BASIC RADAR SKILLS HAVE DETERIORATED. I'M GOING TO DIG OUT THE WX RADAR TRAINING TAPES AGAIN BEFORE MY NEXT 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.