Narrative:

At approximately 12,000 ft, captain's airspeed, altimeter, vsi, sweep clock all quit working at the same moment a window overheat happened. Approximately 5-10 mins earlier, we had the flight attendant's shut off the handle underneath the sink in the forward lavatory due to a running faucet that wouldn't shut off per maintenance control instructions. I assumed control of the plane, and landed in VMC conditions with my instruments working except intermittent GS/localizer flags on the first officer side. After the fact, and after talking with mechanics the next morning, our best guess is the flight attendant inadvertently didn't shut off the handle, but instead moved it to drain. This caused a burst water line, then water got into the east&east compartment, thus causing the instrument problems. Upon post flight inspection, water was visibly and noticeably coming out just fore and aft of the east&east compartment. It should be noted that while this procedure is in the irregular operations manual, the shut off valves are not in any way labeled well, and all flight attendant's we spoke to said they've never had recurrent training on this procedure. We looked ourselves and there is no placard or warning that we could see. Also of note, we could find nowhere is there a precaution in the aom, fom, or qrc for this procedure and maintenance control offered no guidance as a precaution. I highly recommend this procedure be reviewed and much more readable, large placards be put on the valve. Callback conversation with reporter revealed the following information: the reporter stated that when the east&east compartment was opened, water poured out like a dam broke. The reporter said all of the units in the compartment were replaced. The reporter stated the flight operations manual does not refer to the lavatory valves and valve positions, and neither does the cabin attendant's handbook give any description and operation of the valves. The reporter said the cabin attendants are shown the valves at initial training and never receive any recurrent training again.

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Original NASA ASRS Text

Title: A B737-300 IN DSCNT AT 12000 FT HAS CAPT'S AIRSPD, ALTIMETER, VSI, SWEEP CLOCK QUIT AND A WINDSHIELD OVERHEAT HAPPEN AT THE SAME MOMENT. BURST WATER LINE CAUSED A FLOODED ELECTRICAL AND ELECTRONICS COMPARTMENT.

Narrative: AT APPROX 12,000 FT, CAPT'S AIRSPEED, ALTIMETER, VSI, SWEEP CLOCK ALL QUIT WORKING AT THE SAME MOMENT A WINDOW OVERHEAT HAPPENED. APPROX 5-10 MINS EARLIER, WE HAD THE FA'S SHUT OFF THE HANDLE UNDERNEATH THE SINK IN THE FORWARD LAVATORY DUE TO A RUNNING FAUCET THAT WOULDN'T SHUT OFF PER MAINT CTL INSTRUCTIONS. I ASSUMED CTL OF THE PLANE, AND LANDED IN VMC CONDITIONS WITH MY INSTRUMENTS WORKING EXCEPT INTERMITTENT GS/LOC FLAGS ON THE FO SIDE. AFTER THE FACT, AND AFTER TALKING WITH MECHANICS THE NEXT MORNING, OUR BEST GUESS IS THE FLT ATTENDANT INADVERTENTLY DIDN'T SHUT OFF THE HANDLE, BUT INSTEAD MOVED IT TO DRAIN. THIS CAUSED A BURST WATER LINE, THEN WATER GOT INTO THE E&E COMPARTMENT, THUS CAUSING THE INST PROBS. UPON POST FLT INSPECTION, WATER WAS VISIBLY AND NOTICEABLY COMING OUT JUST FORE AND AFT OF THE E&E COMPARTMENT. IT SHOULD BE NOTED THAT WHILE THIS PROC IS IN THE IRREGULAR OPS MANUAL, THE SHUT OFF VALVES ARE NOT IN ANY WAY LABELED WELL, AND ALL FLT ATTENDANT'S WE SPOKE TO SAID THEY'VE NEVER HAD RECURRENT TRAINING ON THIS PROC. WE LOOKED OURSELVES AND THERE IS NO PLACARD OR WARNING THAT WE COULD SEE. ALSO OF NOTE, WE COULD FIND NOWHERE IS THERE A PRECAUTION IN THE AOM, FOM, OR QRC FOR THIS PROC AND MAINT CTL OFFERED NO GUIDANCE AS A PRECAUTION. I HIGHLY RECOMMEND THIS PROC BE REVIEWED AND MUCH MORE READABLE, LARGE PLACARDS BE PUT ON THE VALVE. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED THAT WHEN THE E&E COMPARTMENT WAS OPENED, WATER POURED OUT LIKE A DAM BROKE. THE RPTR SAID ALL OF THE UNITS IN THE COMPARTMENT WERE REPLACED. THE RPTR STATED THE FLT OPS MANUAL DOES NOT REFER TO THE LAVATORY VALVES AND VALVE POSITIONS, AND NEITHER DOES THE CABIN ATTENDANT'S HANDBOOK GIVE ANY DESCRIPTION AND OPERATION OF THE VALVES. THE RPTR SAID THE CABIN ATTENDANTS ARE SHOWN THE VALVES AT INITIAL TRAINING AND NEVER RECEIVE ANY RECURRENT TRAINING AGAIN.

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.