Narrative:

I was contacted at FBO on nov/fri/02 at approximately XA40. Talked to air carrier X captain on aircraft X. Advised me that pfd was inoperative. I contacted air carrier X maintenance control and was advised to swap pfd with first officer navigation display. Upon my removal of the pfd, I noticed water on the unit. Stopping the procedure there, I advised air carrier X maintenance control. Controller suggested checking panel at windshield wiper. I did find 3 or 4 screws about 1/2 turn loose and advised maintenance control. I was advised to dry area and proceed with swap of units. Area was dried, wiped with paper towel -- no evidence of further moisture seen. Felt around in panel opening for moisture, none noted. Performed visual look with flashlight. No visible signs of moisture. Completed swap and pwred up cockpit. Captain performed operations check of units as directed in maintenance manual 34-22-06-201. All checked normal. Completed required paperwork and released aircraft. At approximately XE30 I received call to notify me that crew declared an emergency on descent into ZZZ airport (original destination) with smoke in cockpit. Aircraft landed without further incident. As of XF30, cause is still under investigation. Air carrier X controller mentioned captain noted some moisture during pushback from gate, however, elected to take aircraft X. Apparently water was laying on the interior covers above pfd and was not detectable until aircraft was on descent. I don't know what could have been done differently to prevent this. Maybe remove exterior panel and inspect, however, sealant was in place and in good shape. The protective covers that help keep water away from avionics, actually did as much harm as good in this situation.

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Original NASA ASRS Text

Title: AN MD88 CONTRACT TECHNICIAN RPTS DISCOVERING MOISTURE BEHIND THE CAPT'S INST PANEL RENDERING THE PFD INOP.

Narrative: I WAS CONTACTED AT FBO ON NOV/FRI/02 AT APPROX XA40. TALKED TO ACR X CAPT ON ACFT X. ADVISED ME THAT PFD WAS INOP. I CONTACTED ACR X MAINT CTL AND WAS ADVISED TO SWAP PFD WITH FO NAV DISPLAY. UPON MY REMOVAL OF THE PFD, I NOTICED WATER ON THE UNIT. STOPPING THE PROC THERE, I ADVISED ACR X MAINT CTL. CTLR SUGGESTED CHKING PANEL AT WINDSHIELD WIPER. I DID FIND 3 OR 4 SCREWS ABOUT 1/2 TURN LOOSE AND ADVISED MAINT CTL. I WAS ADVISED TO DRY AREA AND PROCEED WITH SWAP OF UNITS. AREA WAS DRIED, WIPED WITH PAPER TOWEL -- NO EVIDENCE OF FURTHER MOISTURE SEEN. FELT AROUND IN PANEL OPENING FOR MOISTURE, NONE NOTED. PERFORMED VISUAL LOOK WITH FLASHLIGHT. NO VISIBLE SIGNS OF MOISTURE. COMPLETED SWAP AND PWRED UP COCKPIT. CAPT PERFORMED OPS CHK OF UNITS AS DIRECTED IN MAINT MANUAL 34-22-06-201. ALL CHKED NORMAL. COMPLETED REQUIRED PAPERWORK AND RELEASED ACFT. AT APPROX XE30 I RECEIVED CALL TO NOTIFY ME THAT CREW DECLARED AN EMER ON DSCNT INTO ZZZ ARPT (ORIGINAL DEST) WITH SMOKE IN COCKPIT. ACFT LANDED WITHOUT FURTHER INCIDENT. AS OF XF30, CAUSE IS STILL UNDER INVESTIGATION. ACR X CTLR MENTIONED CAPT NOTED SOME MOISTURE DURING PUSHBACK FROM GATE, HOWEVER, ELECTED TO TAKE ACFT X. APPARENTLY WATER WAS LAYING ON THE INTERIOR COVERS ABOVE PFD AND WAS NOT DETECTABLE UNTIL ACFT WAS ON DSCNT. I DON'T KNOW WHAT COULD HAVE BEEN DONE DIFFERENTLY TO PREVENT THIS. MAYBE REMOVE EXTERIOR PANEL AND INSPECT, HOWEVER, SEALANT WAS IN PLACE AND IN GOOD SHAPE. THE PROTECTIVE COVERS THAT HELP KEEP WATER AWAY FROM AVIONICS, ACTUALLY DID AS MUCH HARM AS GOOD IN THIS SIT.

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.