Narrative:

During preflight WX briefing, it looked like I could proceed 1/2 way to final destination before getting into bad WX. Forecast was icing in clouds and precipitation. Reports of severe ice were provided beyond 1/2 way point (rime was forecast). (I had previously flown in forecast light mixed icing with 2000 ft between MEA and freezing level. This worked well and had come to consider this type of out as my rule.) I filed to final destination figuring on flying to midway, landing, and checking WX again. The first 1/4 of filed flight was clear with light chop. (My previous icing experiences were smooth, stratus icings.) upon first entering clouds, I frequently checked for frost on the black tires. I was listening to reports of rapid ice buildup higher and further along my route but my tires remained black. When I started collecting frost, it also started getting bumby. I waited a couple mins to see rate of buildup, trying to estimate if I could make it to the midway alternate. After accumulating up to 1/8 inch ice in spots, I informed center that I needed to do a 180 degree turn and return. I received clearance to turn left 180 degrees and began my turn. During the turn, I became distraction, looking for the cloud floor below me in case I needed an emergency exit from clouds. (The published MEA is 12000 ft and along this route the terrain was rising and the ceiling was lowering. However, it had only been 10 mins ago that the ceiling was 12000 ft and I thought it was reasonable to take a look.) the distraction led to a 500 ft descent and nearly a 360 degree turn. Center asked my intentions and I said I was looking for clear of clouds lower. I continued my turn but began to lose attitude control as I began to worry about my situation. I was worried about pulling up and regaining altitude because I was losing altitude without gaining speed and was attributing that to ice buildup. (However, I suspect now that the general air flow was descending in the area where I was picking up ice and should have focused on return heading and regaining or at least maintaining altitude.) at approximately 1000 ft below MEA, I spotted clear air in what was obviously (despite my loss of forward visibility) a nice wide valley. Center cautioned me that there was terrain at my altitude and I looked out the other side (right) and noticed terrain beside me very close (1000-1500 ft horizontally). The terrain was lower to my side (left) and I quickly banked hard left and stepped on the left rudder all the way. This was all reflex because it happened very quickly (my airspeed was between 90-100 KTS). I descended down the wide (over 1 mi) valley away from higher terrain making small turns right and left to see ahead of me. Center asked my intentions and I apologized for maneuvering without clearance and informed him that I was in visual conditions and would like to cancel my IFR clearance. Finally, what saved my bacon was my handheld non-IFR GPS showing my position relative to nearest uncontrolled airstrips. I was also fortunate to have the sectional chart for my area open. (I typically fly, both VFR and IFR, with both types of charts open and I follow both during the normally slow en route phases.) to make a long story a little shorter, I made it to fbr and landed. The thing that surprised me about the ice was that it took so long to melt off. Previously, I had experienced ice that was wetter and melted quickly only a degree or more above freezing. This time, I was flying around at 9500 ft MSL and 40 F for 1/2 hour before I could see through most of my forward window. The other thing that surprised me, upon later reflection, was that my supposed 'rule' had been so easily violated. In other words, I flew into forecast ice without a clear 'out.' I hadn't determined what the ceiling or freezing levels were and seen if these compared favorably with the MEA. I believe, like many pilots in this region (including 4 instructors and my IFR examiner), that flight into icing conditions is to be expected unless you want to mothball your plane for 6 months each yr. Unfortunately, there is little published guidance on reasonable approachs by single engine planes into icing conditions. I now feel that certain prerequisites would be reasonable for such flts: 1) recent flight maneuver experience, not just 6 approachs and a hold in 6 months, 2) at least 1000 ft berth between freezing level and MEA. 3) no forecast rain -- not just 'well, I'll turn around if I hit rain.' I had flown into forecast icing conditions without any certainty of a lower and warmer exit. The fact that I found lower and warmer was just plain luck. I ignored my clearance limitations (heading and altitude) when in an emergency situation without declaring an emergency. A contributing factor was my rust under the hood. By this I mean that it had been a few months since I had worked on flight maneuvers with a safety pilot or instructor or on my home simulator. Add to that the light turbulence, and my situation deteriorated quickly. Another contributing factor, I wanted to get home. I feel this situation led me to bend what I thought had been rules and accept a bad flight plan as something that was better than a worse flight plan (in other words, trying to fly a little way into terrible conditions instead of a long way into terrible conditions). And finally, another contributing factor was that the first day of the business trip was beautiful WX. Warm, clear, reasonable calm. I figured it wasn't likely to change very much that quickly. What I should have done was gotten a multi-day forecast. My minimum corrective actions include some ground and air work with a cfii, developing a checklist before flts into possible icing, also developing a checklist before flight into IMC with turbulence, and 1 hour of simulator work each month.

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Original NASA ASRS Text

Title: A C172 PLT FLEW INTO ICING CONDITIONS, REQUIRING DEVS FROM ATC ASSIGNED ALT AND HDG CLRNCS.

Narrative: DURING PREFLT WX BRIEFING, IT LOOKED LIKE I COULD PROCEED 1/2 WAY TO FINAL DEST BEFORE GETTING INTO BAD WX. FORECAST WAS ICING IN CLOUDS AND PRECIP. RPTS OF SEVERE ICE WERE PROVIDED BEYOND 1/2 WAY POINT (RIME WAS FORECAST). (I HAD PREVIOUSLY FLOWN IN FORECAST LIGHT MIXED ICING WITH 2000 FT BTWN MEA AND FREEZING LEVEL. THIS WORKED WELL AND HAD COME TO CONSIDER THIS TYPE OF OUT AS MY RULE.) I FILED TO FINAL DEST FIGURING ON FLYING TO MIDWAY, LNDG, AND CHKING WX AGAIN. THE FIRST 1/4 OF FILED FLT WAS CLR WITH LIGHT CHOP. (MY PREVIOUS ICING EXPERIENCES WERE SMOOTH, STRATUS ICINGS.) UPON FIRST ENTERING CLOUDS, I FREQUENTLY CHKED FOR FROST ON THE BLACK TIRES. I WAS LISTENING TO RPTS OF RAPID ICE BUILDUP HIGHER AND FURTHER ALONG MY RTE BUT MY TIRES REMAINED BLACK. WHEN I STARTED COLLECTING FROST, IT ALSO STARTED GETTING BUMBY. I WAITED A COUPLE MINS TO SEE RATE OF BUILDUP, TRYING TO ESTIMATE IF I COULD MAKE IT TO THE MIDWAY ALTERNATE. AFTER ACCUMULATING UP TO 1/8 INCH ICE IN SPOTS, I INFORMED CTR THAT I NEEDED TO DO A 180 DEG TURN AND RETURN. I RECEIVED CLRNC TO TURN L 180 DEGS AND BEGAN MY TURN. DURING THE TURN, I BECAME DISTR, LOOKING FOR THE CLOUD FLOOR BELOW ME IN CASE I NEEDED AN EMER EXIT FROM CLOUDS. (THE PUBLISHED MEA IS 12000 FT AND ALONG THIS RTE THE TERRAIN WAS RISING AND THE CEILING WAS LOWERING. HOWEVER, IT HAD ONLY BEEN 10 MINS AGO THAT THE CEILING WAS 12000 FT AND I THOUGHT IT WAS REASONABLE TO TAKE A LOOK.) THE DISTR LED TO A 500 FT DSCNT AND NEARLY A 360 DEG TURN. CTR ASKED MY INTENTIONS AND I SAID I WAS LOOKING FOR CLR OF CLOUDS LOWER. I CONTINUED MY TURN BUT BEGAN TO LOSE ATTITUDE CTL AS I BEGAN TO WORRY ABOUT MY SIT. I WAS WORRIED ABOUT PULLING UP AND REGAINING ALT BECAUSE I WAS LOSING ALT WITHOUT GAINING SPD AND WAS ATTRIBUTING THAT TO ICE BUILDUP. (HOWEVER, I SUSPECT NOW THAT THE GENERAL AIR FLOW WAS DSNDING IN THE AREA WHERE I WAS PICKING UP ICE AND SHOULD HAVE FOCUSED ON RETURN HDG AND REGAINING OR AT LEAST MAINTAINING ALT.) AT APPROX 1000 FT BELOW MEA, I SPOTTED CLR AIR IN WHAT WAS OBVIOUSLY (DESPITE MY LOSS OF FORWARD VISIBILITY) A NICE WIDE VALLEY. CTR CAUTIONED ME THAT THERE WAS TERRAIN AT MY ALT AND I LOOKED OUT THE OTHER SIDE (R) AND NOTICED TERRAIN BESIDE ME VERY CLOSE (1000-1500 FT HORIZLY). THE TERRAIN WAS LOWER TO MY SIDE (L) AND I QUICKLY BANKED HARD L AND STEPPED ON THE L RUDDER ALL THE WAY. THIS WAS ALL REFLEX BECAUSE IT HAPPENED VERY QUICKLY (MY AIRSPD WAS BTWN 90-100 KTS). I DSNDED DOWN THE WIDE (OVER 1 MI) VALLEY AWAY FROM HIGHER TERRAIN MAKING SMALL TURNS R AND L TO SEE AHEAD OF ME. CTR ASKED MY INTENTIONS AND I APOLOGIZED FOR MANEUVERING WITHOUT CLRNC AND INFORMED HIM THAT I WAS IN VISUAL CONDITIONS AND WOULD LIKE TO CANCEL MY IFR CLRNC. FINALLY, WHAT SAVED MY BACON WAS MY HANDHELD NON-IFR GPS SHOWING MY POS RELATIVE TO NEAREST UNCTLED AIRSTRIPS. I WAS ALSO FORTUNATE TO HAVE THE SECTIONAL CHART FOR MY AREA OPEN. (I TYPICALLY FLY, BOTH VFR AND IFR, WITH BOTH TYPES OF CHARTS OPEN AND I FOLLOW BOTH DURING THE NORMALLY SLOW ENRTE PHASES.) TO MAKE A LONG STORY A LITTLE SHORTER, I MADE IT TO FBR AND LANDED. THE THING THAT SURPRISED ME ABOUT THE ICE WAS THAT IT TOOK SO LONG TO MELT OFF. PREVIOUSLY, I HAD EXPERIENCED ICE THAT WAS WETTER AND MELTED QUICKLY ONLY A DEG OR MORE ABOVE FREEZING. THIS TIME, I WAS FLYING AROUND AT 9500 FT MSL AND 40 F FOR 1/2 HR BEFORE I COULD SEE THROUGH MOST OF MY FORWARD WINDOW. THE OTHER THING THAT SURPRISED ME, UPON LATER REFLECTION, WAS THAT MY SUPPOSED 'RULE' HAD BEEN SO EASILY VIOLATED. IN OTHER WORDS, I FLEW INTO FORECAST ICE WITHOUT A CLR 'OUT.' I HADN'T DETERMINED WHAT THE CEILING OR FREEZING LEVELS WERE AND SEEN IF THESE COMPARED FAVORABLY WITH THE MEA. I BELIEVE, LIKE MANY PLTS IN THIS REGION (INCLUDING 4 INSTRUCTORS AND MY IFR EXAMINER), THAT FLT INTO ICING CONDITIONS IS TO BE EXPECTED UNLESS YOU WANT TO MOTHBALL YOUR PLANE FOR 6 MONTHS EACH YR. UNFORTUNATELY, THERE IS LITTLE PUBLISHED GUIDANCE ON REASONABLE APCHS BY SINGLE ENG PLANES INTO ICING CONDITIONS. I NOW FEEL THAT CERTAIN PREREQUISITES WOULD BE REASONABLE FOR SUCH FLTS: 1) RECENT FLT MANEUVER EXPERIENCE, NOT JUST 6 APCHS AND A HOLD IN 6 MONTHS, 2) AT LEAST 1000 FT BERTH BTWN FREEZING LEVEL AND MEA. 3) NO FORECAST RAIN -- NOT JUST 'WELL, I'LL TURN AROUND IF I HIT RAIN.' I HAD FLOWN INTO FORECAST ICING CONDITIONS WITHOUT ANY CERTAINTY OF A LOWER AND WARMER EXIT. THE FACT THAT I FOUND LOWER AND WARMER WAS JUST PLAIN LUCK. I IGNORED MY CLRNC LIMITATIONS (HDG AND ALT) WHEN IN AN EMER SIT WITHOUT DECLARING AN EMER. A CONTRIBUTING FACTOR WAS MY RUST UNDER THE HOOD. BY THIS I MEAN THAT IT HAD BEEN A FEW MONTHS SINCE I HAD WORKED ON FLT MANEUVERS WITH A SAFETY PLT OR INSTRUCTOR OR ON MY HOME SIMULATOR. ADD TO THAT THE LIGHT TURB, AND MY SIT DETERIORATED QUICKLY. ANOTHER CONTRIBUTING FACTOR, I WANTED TO GET HOME. I FEEL THIS SIT LED ME TO BEND WHAT I THOUGHT HAD BEEN RULES AND ACCEPT A BAD FLT PLAN AS SOMETHING THAT WAS BETTER THAN A WORSE FLT PLAN (IN OTHER WORDS, TRYING TO FLY A LITTLE WAY INTO TERRIBLE CONDITIONS INSTEAD OF A LONG WAY INTO TERRIBLE CONDITIONS). AND FINALLY, ANOTHER CONTRIBUTING FACTOR WAS THAT THE FIRST DAY OF THE BUSINESS TRIP WAS BEAUTIFUL WX. WARM, CLR, REASONABLE CALM. I FIGURED IT WASN'T LIKELY TO CHANGE VERY MUCH THAT QUICKLY. WHAT I SHOULD HAVE DONE WAS GOTTEN A MULTI-DAY FORECAST. MY MINIMUM CORRECTIVE ACTIONS INCLUDE SOME GND AND AIR WORK WITH A CFII, DEVELOPING A CHKLIST BEFORE FLTS INTO POSSIBLE ICING, ALSO DEVELOPING A CHKLIST BEFORE FLT INTO IMC WITH TURB, AND 1 HR OF SIMULATOR WORK EACH MONTH.

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.