A PA34 lost the airspeed indicator in descent probably due to pitot icing. The indicator returned to...

Attributes
ACN	1012090
Time
Date	201205
Local Time Of Day	1201-1800
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Light	Daylight
Aircraft 1
Make Model Name	PA-34 Seneca Undifferentiated
Operating Under FAR Part	Part 91
Flight Phase	Descent
Route In Use	Direct
Flight Plan	IFR
Component
Aircraft Component	Airspeed Indicator
Person 1
Function	Pilot Flying Single Pilot
Qualification	Flight Crew Multiengine
Experience	Flight Crew Last 90 Days 100 Flight Crew Total 4400 Flight Crew Type 325
Events
Anomaly	Aircraft Equipment Problem Critical Inflight Event / Encounter Weather / Turbulence

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.

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.