Narrative:

We were in cruise, inbound to sea at 15 DME on sea 101 degree radial. We encountered moderate rime icing that built up to 1 inch. We were unable to maintain altitude to keep aircraft under control and lost 500 ft. As we descended through 200-300 ft below assigned altitude, I notified approach and we were cleared to 7000 ft. We had already popped our boots and were close to a usual descent gate. We descended on our own to maintain aircraft control as aircraft was beginning to want to roll and we had to keep airspeed up.

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Original NASA ASRS Text

Title: COMMUTER ACFT ENCOUNTERS ICING. UNABLE TO MAINTAIN ALT. ALT EXCURSION PRIOR TO DSCNT CLRNC.

Narrative: WE WERE IN CRUISE, INBOUND TO SEA AT 15 DME ON SEA 101 DEG RADIAL. WE ENCOUNTERED MODERATE RIME ICING THAT BUILT UP TO 1 INCH. WE WERE UNABLE TO MAINTAIN ALT TO KEEP ACFT UNDER CTL AND LOST 500 FT. AS WE DSNDED THROUGH 200-300 FT BELOW ASSIGNED ALT, I NOTIFIED APCH AND WE WERE CLRED TO 7000 FT. WE HAD ALREADY POPPED OUR BOOTS AND WERE CLOSE TO A USUAL DSCNT GATE. WE DSNDED ON OUR OWN TO MAINTAIN ACFT CTL AS ACFT WAS BEGINNING TO WANT TO ROLL AND WE HAD TO KEEP AIRSPD UP.

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.