Narrative:

Upon climb out from bryce canyon, ut, on IFR flight plan from 15000 to 17000 MSL. Entered clouds and turned on pitot heat prior to cloud entry. Near 17000 airspeed dropped considerably. Turned on alternate air. Manifold pressure dropped 10 inches from 28 inches to 18 inches and full power, full rich mixture. Asked center for descent to 15000. Request granted and started descent. Airspeed still dropping. Pilot attempted to find VFR on descent by turning approximately 90 degree to the left. Not knowing if air source had iced up, since little power available and very low airspeed. To find VFR to verify altitude was mandatory, thus the 90 degree left 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 left turn back around to original heading less 30 degree to reintercept the airway to grand junction, co. Was questioned by ATC as to the 360 degree turn. Pilot replied 'had an engine problem'. Should have put on pitot heat much earlier to avoid ice build up. Initial left turn was mandatory to find VFR to determine altitude of aircraft. Should have informed ATC but was too busy.

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Original NASA ASRS Text

Title: 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.

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.