Narrative:

While descending from 17;000 ft in IMC we passed through a snow storm and lost the air speed indicator. While in the descent the airspeed fell to 120 KTS and continued decreasing to 60 KTS and I became concerned with an imminent stall and lost altitude awareness. When the airspeed went to zero I looked at the GPS airspeed which was nearly 200 KTS ground speed and realized we had a faulty airspeed indication and slowed our descent. I had checked the pitot heat operation before take off and my mechanic checked it post landing. Both times pitot heat was operational. After descending below the clouds the airspeed indicator became operational again.

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Original NASA ASRS Text

Title: A PA34 lost the airspeed indicator in descent probably due to pitot icing. The indicator returned to normal after leaving icing conditions.

Narrative: While descending from 17;000 FT in IMC we passed through a snow storm and lost the air speed indicator. While in the descent the airspeed fell to 120 KTS and continued decreasing to 60 KTS and I became concerned with an imminent stall and lost altitude awareness. When the airspeed went to zero I looked at the GPS airspeed which was nearly 200 KTS ground speed and realized we had a faulty airspeed indication and slowed our descent. I had checked the pitot heat operation before take off and my Mechanic checked it post landing. Both times pitot heat was operational. After descending below the clouds the airspeed indicator became operational again.

Data retrieved from NASA's ASRS site as of July 2013 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.