B767 Undifferentiated or Other Model
Flight Crew Last 90 Days 215; Flight Crew Total 10907; Flight Crew Type 10364
Aircraft Equipment Problem Critical
General Maintenance Action
Aircraft; Human Factors
First Officer noticed a stream of water coming off the tailskid on his walk around inspection.  The water was frigid.  ZZZ maintenance was advised and upon further inspection found a fairly large block of ice in the tail of the aircraft which was melting due to the heat from the APU and high ambient temps on the ramp. This block of ice was resting inches from the stabilizer position transmission module and a wire harness that was partly in-cased in ice.  We immediately broke the [Maintenance Document] and waited to here from Maintenance the cause of the problem.  Obviously water was getting into this area and freezing at altitude.  After further inspection; Maintenance found a drain hole that had been blocked by some debris causing water to sit and freeze.  The residual ice was removed; the drain was cleared and Maintenance signed off the aircraft.  We were satisfied with the explanation and the fix and proceeded to operate the flight to ZZZ1.
B767 pilot noticed ice water dripping from tail skid during preflight walk-around. Ice removed and proceeded with flight.