Narrative:

Just prior to departure, the aft lavatory smoke detector chime started going off like crazy. Aircraft maintenance was right there at the forward entry. He checked out the problem and placarded the aft left lavatory. In the meantime, I went in the forward lavatory and found very little water coming out of the lines. No big deal. Now, during climb out, I went to turn on the autoplt, and it would not engage. Switched over to DFGS C2, and it still would not engage. Momentarily, the rudder was acting up like there was no yaw damper. This problem was short lived. I wound up hand flying the rest of the leg to ZZZ1. A short while later, the flight attendants reported no water at all in the lavatories or galleys. Upon arrival in ZZZ1, the awaiting mechanic said that yesterday the water lines in the aircraft froze, then broke, and water went all over. My first officer did a postflt walkaround and found chunks of ice under the aircraft, and the ramp guys were unable to open the aft cargo door. All of the ZZZ1 mechanics now knew the problem, and that a water leak was most likely the common denominator.

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Original NASA ASRS Text

Title: A MD80 ON CLBOUT, CREW DISCOVERED #1 AND #2 FLT GUIDANCE SYS WOULD NOT ENGAGE AND MOMENTARY YAW DAMPER PROBS. CAUSED BY BROKEN WATER LINES.

Narrative: JUST PRIOR TO DEP, THE AFT LAVATORY SMOKE DETECTOR CHIME STARTED GOING OFF LIKE CRAZY. ACFT MAINT WAS RIGHT THERE AT THE FORWARD ENTRY. HE CHKED OUT THE PROB AND PLACARDED THE AFT L LAVATORY. IN THE MEANTIME, I WENT IN THE FORWARD LAVATORY AND FOUND VERY LITTLE WATER COMING OUT OF THE LINES. NO BIG DEAL. NOW, DURING CLBOUT, I WENT TO TURN ON THE AUTOPLT, AND IT WOULD NOT ENGAGE. SWITCHED OVER TO DFGS C2, AND IT STILL WOULD NOT ENGAGE. MOMENTARILY, THE RUDDER WAS ACTING UP LIKE THERE WAS NO YAW DAMPER. THIS PROB WAS SHORT LIVED. I WOUND UP HAND FLYING THE REST OF THE LEG TO ZZZ1. A SHORT WHILE LATER, THE FLT ATTENDANTS RPTED NO WATER AT ALL IN THE LAVATORIES OR GALLEYS. UPON ARR IN ZZZ1, THE AWAITING MECH SAID THAT YESTERDAY THE WATER LINES IN THE ACFT FROZE, THEN BROKE, AND WATER WENT ALL OVER. MY FO DID A POSTFLT WALKAROUND AND FOUND CHUNKS OF ICE UNDER THE ACFT, AND THE RAMP GUYS WERE UNABLE TO OPEN THE AFT CARGO DOOR. ALL OF THE ZZZ1 MECHS NOW KNEW THE PROB, AND THAT A WATER LEAK WAS MOST LIKELY THE COMMON DENOMINATOR.

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.