Corp mdt suffers restricted aileron movement during flight.

Attributes
ACN	170769
Time
Date	199102
Day	Tue
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : ewc
State Reference	PA
Altitude	msl bound lower : 28000 msl bound upper : 28000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zob
Operator	general aviation : corporate
Make Model Name	Medium Transport
Navigation In Use	Other
Flight Phase	climbout : intermediate altitude
Flight Plan	IFR
Person 1
Affiliation	Other
Function	flight crew : captain oversight : pic
Qualification	pilot : cfi pilot : atp
Experience	flight time last 90 days : 100 flight time total : 9100 flight time type : 1500
ASRS Report	170769
Person 2
Affiliation	government : faa
Function	controller : radar
Qualification	controller : radar
Events
Anomaly	aircraft equipment problem : critical other anomaly
Independent Detector	other flight crewa
Resolutory Action	aircraft : equipment problem dissipated flight crew : overcame equipment problem flight crew : regained aircraft control flight crew : declared emergency
Consequence	faa : investigated
Supplementary
Primary Problem	Aircraft

Narrative:

Climbing through approximately FL280 en route to FL290 with autoplt operating, observed autoplt mistrim caution indicator illuminated. Disengaged autoplt per abnormal checklist and noticed extreme latitude rigidity (aileron stiffness). With more than normal manual force the latitude controls could be operated, but with restr response. Normal aileron trim was ineffective, but emergency aileron trim produced roll in desired ate and direction. After analyzing all possible sources with company operations, company maintenance and teb, determination was made that possible source of restriction was water from forward potable water tank leaking and flowing rearward to restrict flight control linkages and bell cranks, in latitude mode only. Consensus opinion was that upon descent warmer air temperatures would thaw ice buildup and ctlability would be regained. Continued to destination and descending between FL240 and FL180 latitude control returned to normal. Normal approach and landing completed at sna. Post-flight revealed ice in belly of aircraft from forward potable water tank extending rearward aft of frame 18. Ice varied in thickness from 1/2'-2' thick int he lower area of the wing and fuselage underbelly. H2O tank drained and aircraft returned to mmv for service and analysis.

Original NASA ASRS Text

Title: CORP MDT SUFFERS RESTRICTED AILERON MOVEMENT DURING FLT.

Narrative: CLBING THROUGH APPROX FL280 ENRTE TO FL290 WITH AUTOPLT OPERATING, OBSERVED AUTOPLT MISTRIM CAUTION INDICATOR ILLUMINATED. DISENGAGED AUTOPLT PER ABNORMAL CHKLIST AND NOTICED EXTREME LAT RIGIDITY (AILERON STIFFNESS). WITH MORE THAN NORMAL MANUAL FORCE THE LAT CTLS COULD BE OPERATED, BUT WITH RESTR RESPONSE. NORMAL AILERON TRIM WAS INEFFECTIVE, BUT EMER AILERON TRIM PRODUCED ROLL IN DESIRED ATE AND DIRECTION. AFTER ANALYZING ALL POSSIBLE SOURCES WITH COMPANY OPS, COMPANY MAINT AND TEB, DETERMINATION WAS MADE THAT POSSIBLE SOURCE OF RESTRICTION WAS WATER FROM FORWARD POTABLE WATER TANK LEAKING AND FLOWING REARWARD TO RESTRICT FLT CTL LINKAGES AND BELL CRANKS, IN LAT MODE ONLY. CONSENSUS OPINION WAS THAT UPON DSNT WARMER AIR TEMPS WOULD THAW ICE BUILDUP AND CTLABILITY WOULD BE REGAINED. CONTINUED TO DEST AND DSNDING BTWN FL240 AND FL180 LAT CTL RETURNED TO NORMAL. NORMAL APCH AND LNDG COMPLETED AT SNA. POST-FLT REVEALED ICE IN BELLY OF ACFT FROM FORWARD POTABLE WATER TANK EXTENDING REARWARD AFT OF FRAME 18. ICE VARIED IN THICKNESS FROM 1/2'-2' THICK INT HE LOWER AREA OF THE WING AND FUSELAGE UNDERBELLY. H2O TANK DRAINED AND ACFT RETURNED TO MMV FOR SVC AND ANALYSIS.

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.