Narrative:

I departed abc airport IFR to acd on an EMS flight with clearance to climb to 5000 ft. At about 3000 ft and 5 mi northwest of abc, I noticed a light rime ice on the windscreen. I notified center that I was picking up ice and would like to stay at 3000 ft, proceed direct to acd NDB (IAF) and execute the localizer runway 5 at acd. Acd NDB is 5 mi southwest of acd with an IAF crossing altitude of 3700 ft. In hindsight, this was not a smart request. I was very familiar with the area I was in and did not want to climb any higher. I was not thinking of the 3700 ft IAF altitude at acd NDB. My familiarity with the area gave me a false sense of security that I could 'cut corners.' ATC denied my request for obvious reasons to stay at 3000 ft. ATC cleared me direct acd, but said I needed to be a minimum of 4500 ft. I acknowledged and continued my climb, now remembering that the IAF required 3700 ft. Now en route to acd NDB (about 8 mi away) and climbing, I noticed my rate of climb and airspeed deteriorating. I determined the increased altitude was causing increased ice accumulation. At about 4200 ft I requested a descent to 3700 ft while en route to acd due to the increased ice accumulation. Xz center informed me that I needed to be 'established' to descend and denied my request. I should have declared an emergency at that point. My aircraft was not equipped to fly in icing conditions. ATC could have better served me, and I could have deviated from my assigned altitude had I declared an emergency. I was reluctant to declare an emergency for fear it would draw attention to me and the situation I had put myself in. At 4500 ft and cruise power setting I was only able to maintain 10-20 KTS above my minimum IFR speed. I made the decision to descend and increase airspeed. I was still about 2 mi from the IAF. I told xz center that I was descending to 3700 ft. They asked if I was 'established.' I told them that I was, even though I was not. I just wanted to get a comfortable airspeed back on the aircraft and get back down to a lower altitude. I was cleared for the localizer runway 5 and completed it to an uneventful landing at acd.

Related reports:

Google
 

Original NASA ASRS Text

Title: PLT OF AN EMS HELI DSNDED BELOW ASSIGNED ALT DUE TO ENCOUNTERING ACFT ICING DURING AN IFR FLT.

Narrative: I DEPARTED ABC ARPT IFR TO ACD ON AN EMS FLT WITH CLRNC TO CLB TO 5000 FT. AT ABOUT 3000 FT AND 5 MI NW OF ABC, I NOTICED A LIGHT RIME ICE ON THE WINDSCREEN. I NOTIFIED CTR THAT I WAS PICKING UP ICE AND WOULD LIKE TO STAY AT 3000 FT, PROCEED DIRECT TO ACD NDB (IAF) AND EXECUTE THE LOC RWY 5 AT ACD. ACD NDB IS 5 MI SW OF ACD WITH AN IAF XING ALT OF 3700 FT. IN HINDSIGHT, THIS WAS NOT A SMART REQUEST. I WAS VERY FAMILIAR WITH THE AREA I WAS IN AND DID NOT WANT TO CLB ANY HIGHER. I WAS NOT THINKING OF THE 3700 FT IAF ALT AT ACD NDB. MY FAMILIARITY WITH THE AREA GAVE ME A FALSE SENSE OF SECURITY THAT I COULD 'CUT CORNERS.' ATC DENIED MY REQUEST FOR OBVIOUS REASONS TO STAY AT 3000 FT. ATC CLRED ME DIRECT ACD, BUT SAID I NEEDED TO BE A MINIMUM OF 4500 FT. I ACKNOWLEDGED AND CONTINUED MY CLB, NOW REMEMBERING THAT THE IAF REQUIRED 3700 FT. NOW ENRTE TO ACD NDB (ABOUT 8 MI AWAY) AND CLBING, I NOTICED MY RATE OF CLB AND AIRSPD DETERIORATING. I DETERMINED THE INCREASED ALT WAS CAUSING INCREASED ICE ACCUMULATION. AT ABOUT 4200 FT I REQUESTED A DSCNT TO 3700 FT WHILE ENRTE TO ACD DUE TO THE INCREASED ICE ACCUMULATION. XZ CTR INFORMED ME THAT I NEEDED TO BE 'ESTABLISHED' TO DSND AND DENIED MY REQUEST. I SHOULD HAVE DECLARED AN EMER AT THAT POINT. MY ACFT WAS NOT EQUIPPED TO FLY IN ICING CONDITIONS. ATC COULD HAVE BETTER SERVED ME, AND I COULD HAVE DEVIATED FROM MY ASSIGNED ALT HAD I DECLARED AN EMER. I WAS RELUCTANT TO DECLARE AN EMER FOR FEAR IT WOULD DRAW ATTN TO ME AND THE SIT I HAD PUT MYSELF IN. AT 4500 FT AND CRUISE PWR SETTING I WAS ONLY ABLE TO MAINTAIN 10-20 KTS ABOVE MY MINIMUM IFR SPD. I MADE THE DECISION TO DSND AND INCREASE AIRSPD. I WAS STILL ABOUT 2 MI FROM THE IAF. I TOLD XZ CTR THAT I WAS DSNDING TO 3700 FT. THEY ASKED IF I WAS 'ESTABLISHED.' I TOLD THEM THAT I WAS, EVEN THOUGH I WAS NOT. I JUST WANTED TO GET A COMFORTABLE AIRSPD BACK ON THE ACFT AND GET BACK DOWN TO A LOWER ALT. I WAS CLRED FOR THE LOC RWY 5 AND COMPLETED IT TO AN UNEVENTFUL LNDG AT ACD.

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.