Previously spilled water on avionics panel creates a lost communication later in flight.

Attributes
ACN	141586
Time
Date	199004
Day	Sun
Local Time Of Day	1801 To 2400
Place
Locale Reference	atc facility : clt
State Reference	NC
Altitude	msl bound lower : 25000 msl bound upper : 25000
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Controlling Facilities	artcc : ztl
Operator	common carrier : air carrier
Make Model Name	Large Transport, Low Wing, 3 Turbojet Eng
Flight Phase	cruise other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : cfi pilot : atp pilot : flight engineer
Experience	flight time last 90 days : 220 flight time total : 9800 flight time type : 850
ASRS Report	141586
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial
Events
Anomaly	aircraft equipment problem : less severe non adherence : published procedure non adherence : far non adherence : clearance other anomaly other
Independent Detector	other controllera other flight crewa
Resolutory Action	flight crew : overcame equipment problem
Consequence	faa : reviewed incident with flight crew
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation other

Narrative:

I picked up aircraft en route to iah. Previous captain advised me on his way out that he spilled a full cup of water on the avionics panel. Preflight found radios functioning properly, with just a little more static than usual. En route to iah, captain's audio selector went dead. We continue trip by using observer panel. Iah maintenance installed a new audio panel. System functioned, but static was still present. For the next 1 1/2 hours, everything was normal; however, somewhere in the last 20-30 mins of the trim, #1 VHF communication went dead at all positions. By the time we discovered the unit was dead and not just a missed frequency change, we were past our normal descent point. Trws at destination also related to distract us from the lost communication procedure longer than normal. We then switched to #3 VHF communication (normal backup for #1) and tried center. Apparently the water spill had damaged the frequency selector on #3 VHF communication, so contact was finally established with #2 VHF communication. Obviously center was very upset about our lost communication and wanted to know why we allowed ourselves to be out of contact so long. I should never have assumed that just plain water would evaporate and do no damage. Next time there is a spill, I'll have maintenance check it out.

Original NASA ASRS Text

Title: PREVIOUSLY SPILLED WATER ON AVIONICS PANEL CREATES A LOST COM LATER IN FLT.

Narrative: I PICKED UP ACFT ENRTE TO IAH. PREVIOUS CAPT ADVISED ME ON HIS WAY OUT THAT HE SPILLED A FULL CUP OF WATER ON THE AVIONICS PANEL. PREFLT FOUND RADIOS FUNCTIONING PROPERLY, WITH JUST A LITTLE MORE STATIC THAN USUAL. ENRTE TO IAH, CAPT'S AUDIO SELECTOR WENT DEAD. WE CONTINUE TRIP BY USING OBSERVER PANEL. IAH MAINT INSTALLED A NEW AUDIO PANEL. SYS FUNCTIONED, BUT STATIC WAS STILL PRESENT. FOR THE NEXT 1 1/2 HRS, EVERYTHING WAS NORMAL; HOWEVER, SOMEWHERE IN THE LAST 20-30 MINS OF THE TRIM, #1 VHF COM WENT DEAD AT ALL POSITIONS. BY THE TIME WE DISCOVERED THE UNIT WAS DEAD AND NOT JUST A MISSED FREQ CHANGE, WE WERE PAST OUR NORMAL DSNT POINT. TRWS AT DEST ALSO RELATED TO DISTRACT US FROM THE LOST COM PROC LONGER THAN NORMAL. WE THEN SWITCHED TO #3 VHF COM (NORMAL BACKUP FOR #1) AND TRIED CENTER. APPARENTLY THE WATER SPILL HAD DAMAGED THE FREQ SELECTOR ON #3 VHF COM, SO CONTACT WAS FINALLY ESTABLISHED WITH #2 VHF COM. OBVIOUSLY CENTER WAS VERY UPSET ABOUT OUR LOST COM AND WANTED TO KNOW WHY WE ALLOWED OURSELVES TO BE OUT OF CONTACT SO LONG. I SHOULD NEVER HAVE ASSUMED THAT JUST PLAIN WATER WOULD EVAPORATE AND DO NO DAMAGE. NEXT TIME THERE IS A SPILL, I'LL HAVE MAINT CHK IT OUT.

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.