TKOF ABORTED. SLUSH SNOW CONTAMINATED HORIZ STABILIZER.

Narrative

FLT AS A COMMUTER FLT WITH SIC AND 5 PAX; IFR FLT PLAN GRAND CANYON TO LAS. CONDITIONS: FREEZING VISIBILITY 1-2 MI IN LIGHT TO MODERATE SNOW. ALTHOUGH THE ACFT WAS MANUALLY CLEANED AND VERIFIED CLEAN WITHIN THE 5 MINS THAT PRECEDED OUR TKOF CLRNC; THERE WAS SOME SNOW ON THE AIRFRAME AS WE ROLLED INTO POS. AS THE TKOF WAS BEGUN AND PROCEEDED; I VERIFIED THAT THIS MATERIAL WAS CLRING OFF THE WING PANELS IN THE SLIPSTREAM. THE RWY HAD NOT BEEN PLOWED; WITH 1-2 INCHES OF SNOW AND SLUSH ON THE SURFACE. AS THE ACFT REACHED VR; AND WITH A LITTLE MORE THAN 4000 FT REMAINING; I ABORTED THE TKOF WHEN IT BECAME OBVIOUS THAT ADEQUATE PITCH CTL WAS NOT AVAILABLE. THE ACFT ROLLED OUT WITHOUT INCIDENT; TWR WAS ADVISED; AND WE TAXIED BACK TO THE GATE TO INSPECT THE ACFT. THE INSPECTION REVEALED THAT A CONSIDERABLE AMOUNT OF CONTAMINATION HAD ACCUMULATED ON THE ENTIRE UNDERSURFACE OF THE HORIZ STABILIZER; APPARENTLY THE RESULT OF SPRAY- BACK FROM THE MAIN WHEELS ON THE TKOF ROLL. ABOUT AN HR LATER; THE SNOW STOPPED. THE RWY DRAINED ON ITS OWN. WE CLEANED THE ACFT AGAIN AND DEPARTED AS NORMAL. I HAD PICKED UP THE CLRNC FOR OUR FIRST DEP. THE ATIS WAS RPTING; AS I RECALL; AT LEAST 1 1/2 MI. OUR OPS SPECS REQUIRE AT LEAST 1 MI VISIBILITY FOR TKOF. THE PLT ACTING AS SIC TOLD ME LATER THAT THE TWR AMENDED THE VISIBILITY TO 3/4 MI AS WE WERE CLRED TO TAXI. I DID NOT HEAR THIS; AND AS WELL AS I COULD TELL; VISIBILITY WAS AROUND 1 1/2 MI AS WE BEGAN THE TKOF ROLL. APPARENTLY; THE QUALITY OF OUR COM BROKE DOWN PARTLY DUE TO OUR HASTE AND EFFORT TO GET AIRBORNE WITHIN THE REQUIRED 5 MINS.