PVT PLT OF SMA ACFT DEV FROM ASSIGNED TRACK IN AN ATTEMPT TO REACH VFR CONDITIONS DUE TO LOSS OF ATTITUDE INSTS AND ENG PWR DETERIORATION.

Narrative

UPON CLBOUT FROM BRYCE CANYON; UT; ON IFR FLT PLAN FROM 15000 TO 17000 MSL. ENTERED CLOUDS AND TURNED ON PITOT HEAT PRIOR TO CLOUD ENTRY. NEAR 17000 AIRSPD DROPPED CONSIDERABLY. TURNED ON ALTERNATE AIR. MANIFOLD PRESSURE DROPPED 10 INCHES FROM 28 INCHES TO 18 INCHES AND FULL PWR; FULL RICH MIXTURE. ASKED CTR FOR DSCNT TO 15000. REQUEST GRANTED AND STARTED DSCNT. AIRSPD STILL DROPPING. PLT ATTEMPTED TO FIND VFR ON DSCNT BY TURNING APPROX 90 DEG TO THE L. NOT KNOWING IF AIR SOURCE HAD ICED UP; SINCE LITTLE PWR AVAILABLE AND VERY LOW AIRSPD. TO FIND VFR TO VERIFY ALT WAS MANDATORY; THUS THE 90 DEG L TURN. UPON EXITING THE CLOUDS AT THE BOTTOM; TOOK OFF ALTERNATE AIR AND THE ICE THAT HAD CLOGGED THE PITOT TUBE (RAM AND STATIC) BROKE OFF AND INSTRUMENTATION MANIFOLD PRESSURE RETURNED TO NORMAL. CONTINUED THE L TURN BACK AROUND TO ORIGINAL HDG LESS 30 DEG TO REINTERCEPT THE AIRWAY TO GRAND JUNCTION; CO. WAS QUESTIONED BY ATC AS TO THE 360 DEG TURN. PLT REPLIED 'HAD AN ENG PROBLEM'. SHOULD HAVE PUT ON PITOT HEAT MUCH EARLIER TO AVOID ICE BUILD UP. INITIAL L TURN WAS MANDATORY TO FIND VFR TO DETERMINE ALT OF ACFT. SHOULD HAVE INFORMED ATC BUT WAS TOO BUSY.