Narrative:

On clearance to maintain block airspace 17,000-19,000 attempting to climb out of severe icing. Deviated from centerline of airway by unknown amount and distance. This occurred after failure of autoplt, failure of right engine tachometer. Pitot heat element inadequate allowing temporary freezing over in severe icing causing airspeed to show increase in climb to yellow and rate of climb increase to pegged position. Also during this time, wife (passenger) was having difficulty in plugging oxygen in and getting it working for herself and 2 children. Also concurrently had failure of low thrust detection system due to rapid ice build-up. Callback conversation with reporter revealed the following: reporter unable to recall what airway he was on at the time of the deviation. His original route clearance was RNAV direct but had been amended to place him on airway just before icing began. Autoplt had failed shortly after departure so he had to hand fly the whole trip. Resolution of the problem situation was first to succeed, under difficult conditions of having to hand fly with confusing flight instrument indications, in getting oxygen supply problems for passenger solved. Then, with full attention back to flying was able to rejoin airway, descend to MEA altitudes which stopped icing and restored instruments. Landed routinely at destination airport. He said he had gotten a thorough WX brief and icing was not forecast along planned route of flight. Aircraft is certified for icing, however.

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Original NASA ASRS Text

Title: SMA TWIN ON IFR TRIP ENCOUNTERS ICING ENROUTE.

Narrative: ON CLRNC TO MAINTAIN BLOCK AIRSPACE 17,000-19,000 ATTEMPTING TO CLIMB OUT OF SEVERE ICING. DEVIATED FROM CENTERLINE OF AIRWAY BY UNKNOWN AMOUNT AND DISTANCE. THIS OCCURRED AFTER FAILURE OF AUTOPLT, FAILURE OF RIGHT ENGINE TACHOMETER. PITOT HEAT ELEMENT INADEQUATE ALLOWING TEMPORARY FREEZING OVER IN SEVERE ICING CAUSING AIRSPEED TO SHOW INCREASE IN CLIMB TO YELLOW AND RATE OF CLIMB INCREASE TO PEGGED POSITION. ALSO DURING THIS TIME, WIFE (PAX) WAS HAVING DIFFICULTY IN PLUGGING OXYGEN IN AND GETTING IT WORKING FOR HERSELF AND 2 CHILDREN. ALSO CONCURRENTLY HAD FAILURE OF LOW THRUST DETECTION SYSTEM DUE TO RAPID ICE BUILD-UP. CALLBACK CONVERSATION WITH REPORTER REVEALED THE FOLLOWING: REPORTER UNABLE TO RECALL WHAT AIRWAY HE WAS ON AT THE TIME OF THE DEVIATION. HIS ORIGINAL ROUTE CLRNC WAS RNAV DIRECT BUT HAD BEEN AMENDED TO PLACE HIM ON AIRWAY JUST BEFORE ICING BEGAN. AUTOPLT HAD FAILED SHORTLY AFTER DEP SO HE HAD TO HAND FLY THE WHOLE TRIP. RESOLUTION OF THE PROBLEM SITUATION WAS FIRST TO SUCCEED, UNDER DIFFICULT CONDITIONS OF HAVING TO HAND FLY WITH CONFUSING FLT INSTRUMENT INDICATIONS, IN GETTING OXYGEN SUPPLY PROBLEMS FOR PAX SOLVED. THEN, WITH FULL ATTN BACK TO FLYING WAS ABLE TO REJOIN AIRWAY, DSND TO MEA ALTS WHICH STOPPED ICING AND RESTORED INSTRUMENTS. LANDED ROUTINELY AT DEST ARPT. HE SAID HE HAD GOTTEN A THOROUGH WX BRIEF AND ICING WAS NOT FORECAST ALONG PLANNED ROUTE OF FLT. ACFT IS CERTIFIED FOR ICING, HOWEVER.

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.