Multiple problems during climb in icing conditions leads to diversion and precautionary landing.

Attributes
ACN	473361
Time
Date	200005
Day	Fri
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : zfw.artcc
State Reference	TX
Altitude	msl single value : 19000
Environment
Weather Elements	Ice
Aircraft 1
Controlling Facilities	artcc : zfw.artcc
Operator	common carrier : air carrier
Make Model Name	Fokker 100
Operating Under FAR Part	Part 121
Flight Phase	climbout : intermediate altitude
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
ASRS Report	473361
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : multi engine pilot : instrument pilot : commercial
Events
Independent Detector	other flight crewa
Resolutory Action	flight crew : overcame equipment problem flight crew : landed as precaution
Consequence	other
Supplementary
Problem Areas	Aircraft Weather
Primary Problem	Aircraft

Narrative:

On climb out from dfw we encountered light to moderate icing in the climb. We had engine and wing anti-ice on. At about FL190 we got a compare speed warning followed immediately by a stabilizer trim yaw damper and autothrottle fail warnings -- all on the #1 system. This was also accompanied by a major split in the throttles. I decided to divert into tul. We notified ATC of our intentions, but I did not declare an emergency. The first officer's and standby instruments were working normally and we were able to fly the airplane normally. We did not want to fly back to dfw because the WX and icing may have been the cause of the problem and tul was VFR and a major maintenance base. We landed at tul without any further problem. Callback conversation with reporter revealed the following information: reporter said that the problems encountered were caused by the failure of a pitot heat system that allowed ice buildup resulting in erroneous inputs to an air data computer. The computer fed the effected system. The problems resolved themselves after descent to warmer altitudes during the arrival to the diversion station.

Original NASA ASRS Text

Title: MULTIPLE PROBS DURING CLB IN ICING CONDITIONS LEADS TO DIVERSION AND PRECAUTIONARY LNDG.

Narrative: ON CLBOUT FROM DFW WE ENCOUNTERED LIGHT TO MODERATE ICING IN THE CLB. WE HAD ENG AND WING ANTI-ICE ON. AT ABOUT FL190 WE GOT A COMPARE SPD WARNING FOLLOWED IMMEDIATELY BY A STABILIZER TRIM YAW DAMPER AND AUTOTHROTTLE FAIL WARNINGS -- ALL ON THE #1 SYS. THIS WAS ALSO ACCOMPANIED BY A MAJOR SPLIT IN THE THROTTLES. I DECIDED TO DIVERT INTO TUL. WE NOTIFIED ATC OF OUR INTENTIONS, BUT I DID NOT DECLARE AN EMER. THE FO'S AND STANDBY INSTS WERE WORKING NORMALLY AND WE WERE ABLE TO FLY THE AIRPLANE NORMALLY. WE DID NOT WANT TO FLY BACK TO DFW BECAUSE THE WX AND ICING MAY HAVE BEEN THE CAUSE OF THE PROB AND TUL WAS VFR AND A MAJOR MAINT BASE. WE LANDED AT TUL WITHOUT ANY FURTHER PROB. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: RPTR SAID THAT THE PROBS ENCOUNTERED WERE CAUSED BY THE FAILURE OF A PITOT HEAT SYS THAT ALLOWED ICE BUILDUP RESULTING IN ERRONEOUS INPUTS TO AN AIR DATA COMPUTER. THE COMPUTER FED THE EFFECTED SYS. THE PROBS RESOLVED THEMSELVES AFTER DSCNT TO WARMER ALTS DURING THE ARR TO THE DIVERSION STATION.

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.