In flight icing encounter, emergency.

Attributes
ACN	104442
Time
Date	198902
Day	Thu
Local Time Of Day	0001 To 0600
Place
Locale Reference	atc facility : swr
State Reference	CA
Altitude	msl bound lower : 10500 msl bound upper : 11700
Environment
Flight Conditions	IMC
Light	Night
Aircraft 1
Controlling Facilities	artcc : zoa artcc : mxkf
Operator	common carrier : air taxi
Make Model Name	Small Transport
Flight Phase	climbout : intermediate altitude cruise other
Route In Use	enroute : on vectors
Flight Plan	IFR
Person 1
Affiliation	company : air taxi
Function	flight crew : single pilot
Qualification	pilot : instrument pilot : commercial pilot : cfi
Experience	flight time last 90 days : 200 flight time total : 4400
ASRS Report	104442
Person 2
Affiliation	government : faa
Function	controller : radar
Qualification	controller : radar
Events
Anomaly	altitude deviation : excursion from assigned altitude inflight encounter : weather other anomaly
Independent Detector	other flight crewa
Resolutory Action	flight crew : regained aircraft control flight crew : declared emergency flight crew : exited adverse environment
Consequence	Other
Supplementary
Primary Problem	Weather

Narrative:

I was climbing to an assigned altitude of 13000', en route from oak to rno. I entered the clouds at approximately 10000' MSL. I noticed a rapid accumulation of ice at approximately 11000' MSL. After repeated cycling of the boots, I realized that the ice was building so fast that I would not be able to climb any higher. I told ZOA, and they cleared me back to 11000'. In cruise flight, the airspeed dropped to 105 KIAS. After 5 mins of cruise the airspeed decayed to 90 KIAS, the airplane buffeted and the stall warning started to sound. I disengaged the autoplt at that point to descend further. The airplane started oscillating up and down, rolled approximately 30 degrees bank to the right, then back to the left approximately 45 degree bank in a nose down attitude. Total altitude loss was approximately 1300'. I climbed back to 10500' in VFR conditions and was still unable to maintain altitude. At that point I diverted to smf and landed west/O further incidence.

Original NASA ASRS Text

Title: IN FLT ICING ENCOUNTER, EMERGENCY.

Narrative: I WAS CLBING TO AN ASSIGNED ALT OF 13000', ENRTE FROM OAK TO RNO. I ENTERED THE CLOUDS AT APPROX 10000' MSL. I NOTICED A RAPID ACCUMULATION OF ICE AT APPROX 11000' MSL. AFTER REPEATED CYCLING OF THE BOOTS, I REALIZED THAT THE ICE WAS BUILDING SO FAST THAT I WOULD NOT BE ABLE TO CLIMB ANY HIGHER. I TOLD ZOA, AND THEY CLRED ME BACK TO 11000'. IN CRUISE FLT, THE AIRSPD DROPPED TO 105 KIAS. AFTER 5 MINS OF CRUISE THE AIRSPD DECAYED TO 90 KIAS, THE AIRPLANE BUFFETED AND THE STALL WARNING STARTED TO SOUND. I DISENGAGED THE AUTOPLT AT THAT POINT TO DSND FURTHER. THE AIRPLANE STARTED OSCILLATING UP AND DOWN, ROLLED APPROX 30 DEGS BANK TO THE RIGHT, THEN BACK TO THE LEFT APPROX 45 DEG BANK IN A NOSE DOWN ATTITUDE. TOTAL ALT LOSS WAS APPROX 1300'. I CLBED BACK TO 10500' IN VFR CONDITIONS AND WAS STILL UNABLE TO MAINTAIN ALT. AT THAT POINT I DIVERTED TO SMF AND LANDED W/O FURTHER INCIDENCE.

Data retrieved from NASA's ASRS site as of August 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.