Narrative:

I was flying a caravan charter flight from kotzebue to anaktuvik pass, alaska. I was at 11000 ft (MSL) on an IFR flight plan kotzebue (PAO7) to anaktuvik pass (pakp) direct. Zan frequency 119.2 works to about 80 mi northeast of kotzebue. I was told to attempt to contact anchorage again approximately 60 mi southwest of anaktuvik pass on another center frequency. There is a gap of about 100 NM where there is no communication available. I began accumulating moderate to severe icing about 100 mi southwest of (pakp) anaktuvik pass and while over very high terrain (6000-9000 ft) my airspeed began to decay due to the severe ice, the de-ice anti-ice equipment could not keep up. I was down to about 110 KIAS when I made the decision to climb. I knew I was close to the tops (it was bright, and often this heavy ice is found near the tops). I climbed to 11500 ft MSL and was in the clear. I reasoned a VFR altitude was a good place to stay until reaching zan. I was unable to contact anchorage until about 50 mi southwest of anaktuvik pass and was told to descend back to 11000 ft. By this time I had shed ice and went back to 11000 ft. I admitted the deviation, but did not declare an emergency. I would do the same in the future. I had an emergency but no one to tell it to.

Related reports:

Google
 

Original NASA ASRS Text

Title: A C208 PLT WHILE ON AN IFR FLT PLAN IN NON RADAR AND NON RADIO CONTACT, HAS TO CLB TO EXIT ICING CONDITIONS WITHOUT A CLRNC.

Narrative: I WAS FLYING A CARAVAN CHARTER FLT FROM KOTZEBUE TO ANAKTUVIK PASS, ALASKA. I WAS AT 11000 FT (MSL) ON AN IFR FLT PLAN KOTZEBUE (PAO7) TO ANAKTUVIK PASS (PAKP) DIRECT. ZAN FREQ 119.2 WORKS TO ABOUT 80 MI NE OF KOTZEBUE. I WAS TOLD TO ATTEMPT TO CONTACT ANCHORAGE AGAIN APPROX 60 MI SW OF ANAKTUVIK PASS ON ANOTHER CTR FREQ. THERE IS A GAP OF ABOUT 100 NM WHERE THERE IS NO COM AVAILABLE. I BEGAN ACCUMULATING MODERATE TO SEVERE ICING ABOUT 100 MI SW OF (PAKP) ANAKTUVIK PASS AND WHILE OVER VERY HIGH TERRAIN (6000-9000 FT) MY AIRSPD BEGAN TO DECAY DUE TO THE SEVERE ICE, THE DE-ICE ANTI-ICE EQUIP COULD NOT KEEP UP. I WAS DOWN TO ABOUT 110 KIAS WHEN I MADE THE DECISION TO CLB. I KNEW I WAS CLOSE TO THE TOPS (IT WAS BRIGHT, AND OFTEN THIS HVY ICE IS FOUND NEAR THE TOPS). I CLBED TO 11500 FT MSL AND WAS IN THE CLR. I REASONED A VFR ALT WAS A GOOD PLACE TO STAY UNTIL REACHING ZAN. I WAS UNABLE TO CONTACT ANCHORAGE UNTIL ABOUT 50 MI SW OF ANAKTUVIK PASS AND WAS TOLD TO DSND BACK TO 11000 FT. BY THIS TIME I HAD SHED ICE AND WENT BACK TO 11000 FT. I ADMITTED THE DEV, BUT DID NOT DECLARE AN EMER. I WOULD DO THE SAME IN THE FUTURE. I HAD AN EMER BUT NO ONE TO TELL IT TO.

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.