A C210 pilot on an IFR flight plan encountered icing conditions and climbed from his assigned altitu...

Attributes
ACN	828469
Time
Date	200903
Local Time Of Day	1201-1800
Place
Locale Reference	ZZZ.ARTCC
State Reference	US
Environment
Flight Conditions	Mixed
Light	Daylight
Aircraft 1
Make Model Name	Cessna 120
Operating Under FAR Part	Part 91
Flight Phase	Cruise
Flight Plan	IFR
Person 1
Function	Pilot Flying Single Pilot
Qualification	Flight Crew Commercial Flight Crew Flight Instructor Flight Crew Instrument Flight Crew Multiengine
Experience	Flight Crew Last 90 Days 42 Flight Crew Total 5200 Flight Crew Type 2650
Events
Anomaly	Deviation - Altitude Excursion From Assigned Altitude Deviation - Procedural Clearance Inflight Event / Encounter Weather / Turbulence Inflight Event / Encounter Other / Unknown

Narrative:

I was on an IFR flight plan flying just above a lower broken to overcast layer. The cloud tops rose and the aircraft was subject to mixed type; moderate to heavy icing. Almost immediately; the airspeed dropped to below 80 KTS (pitot heat was on) and the stall warning horn sounded. In order to exit the icing situation; I immediately began a climb from my assigned altitude. I then informed the controller of my action but did not declare an emergency. In retrospect; I realize I should have first declared an emergency and then initiated the climb above my assigned altitude. I am unsure of the exact time or location of this event; however; I was in contact with center; the time was in the afternoon. I was asked to contact center by telephone on landing. I spoke to center and explained basically what is in this report.

Original NASA ASRS Text

Title: A C210 pilot on an IFR flight plan encountered icing conditions and climbed from his assigned altitude without a clearance.

Narrative: I was on an IFR flight plan flying just above a lower broken to overcast layer. The cloud tops rose and the aircraft was subject to mixed type; moderate to heavy icing. Almost immediately; the airspeed dropped to below 80 KTS (pitot heat was on) and the stall warning horn sounded. In order to exit the icing situation; I immediately began a climb from my assigned altitude. I then informed the Controller of my action but did not declare an emergency. In retrospect; I realize I should have first declared an emergency and then initiated the climb above my assigned altitude. I am unsure of the exact time or location of this event; however; I was in contact with Center; the time was in the afternoon. I was asked to contact Center by telephone on landing. I spoke to Center and explained basically what is in this report.

Data retrieved from NASA's ASRS site as of April 2012 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.