ABORTED TKOF PAST ROTATION SPD.

Narrative

SHORTLY BEFORE DEP; PVD RECEIVED A MODERATE DOWNPOUR OF MIXED FREEZING RAIN; SLEET; AND SNOW. I OBSERVED MAINT DEICING THE ACFT PRIOR TO MY BOARDING. AS I BOARDED VIA AIRSTAIRS; I LOOKED OVER THE L WING FOR ANY EVIDENCE OF ICE; THEN CHKED THE R WING OUT THE FORWARD SVC DOOR AND THEN CHKED BOTH WINGS THROUGH THE WINDOWS AT MID CABIN. WINGS APPEARED CLR OF ANY ICE OR SNOW ALTHOUGH THEY WERE WET WITH DEICING FLUID. AFTER PAXS WERE BOARDED; MAINT AGAIN DROVE AROUND ACFT SPRAYING WITH DEICING FLUID. THE PRECIPITATION STOPPED JUST MOMENTS BEFORE TKOF. OUR TAXI TIME WAS ABOUT 5 MINS. AS TKOF PWR WAS APPLIED; WE GOT A MOMENTARY TKOF WARNING HORN. I CHKED THAT THE SPD BRAKE HANDLE WAS FULLY IN THE DOWN DETENT BY PRESSING DOWN ON THE HANDLE. THE WARNING HORN SILENCED AND DID NOT REOCCUR; AND TKOF ROLL WAS CONTINUED. WHEN THE ACFT WAS ROTATED; THE R WING DID NOT LIFT AT ALL; DESPITE APPROX 45-60 DEGS L AILERON INPUT. I HESITATED THE ROTATION; BUT THE R WING IMMEDIATELY FELL OFF. SUSPECTING POSSIBLE ICE CONTAMINATION OR A POSSIBLE CORRELATION TO THE EARLIER TKOF WARNING HORN I ABORTED THE TKOF AT 120 KTS. WE STOPPED THE ACFT WITH ABOUT 1500 FT OF RWY REMAINING; AND RETURNED TO THE GATE. MAINT CHKED ALL FLT CTLS; FLAPS; SLATS; LEADING EDGES; FLT AND GND SPOILERS AND THE FUEL LOAD. ALL ITEMS CHKED NORMAL. ICE CONTAMINATION COULD NOT BE CONFIRMED NOR ELIMINATED AFTER THE HIGH SPD ABORT AND THE FACT THE TEMP HAD RISEN AFTER THE PRECIPITATION HAD STOPPED. I CAN ONLY SPECULATE AS TO WHETHER ICE WAS THE CAUSE; OR 'IF' THE ACFT WOULD HAVE FLOWN HAD THE TKOF BEEN CONTINUED. A HIGH SPD ABORT DURING ROTATION IS NOT AN ENJOYABLE EVENT. WE WERE FORTUNATE TO HAVE BEEN LIGHTLY LOADED AND TO HAVE HAD A LONG RWY. ALWAYS EXPECT THE UNEXPECTED EVEN AFTER ALL PRECAUTIONS AND PROCS HAVE BEEN TAKEN; ESPECIALLY WITH ICE.