WDB FRT ACFT HAD CARGO LOADED WITH SNOW RESULTING IN MELTING IN FLT CAUSING ICE TO FORM ON CTL CABLES INHIBITING CTL MOVEMENT. DIVERTED TO MSP FOR MAINTENANCE CHECK.

Narrative

AT APPROX XA30 AM; 1/88 JFK; I PREFLT'D A CARGO ACFT; WDB; FOR A NONSTOP FLT TO SEA. THE ACFT WAS LOADED WITH FREIGHT AND CLOSED UP THE ACFT WAS COLD; NO APU RUNNING. I FOUND SOME LIGHT SNOW ON CARGO AND THE ON CARGO DECK DUE TO BLOWING SNOW IN NY THAT DAY. I STARTED APU AND WARMED FLT DECK AND CARGO DECK FOR APPROX 2 HRS BEFORE WE DEPARTED JFK. WE WERE DEICED BY 2 FULL TRUCKS BEFORE DEP. EVERYTHING WAS NORMAL UNTIL APPROX XD15Z AT 35000' OVER ND. WE HAD BEEN CLRD DIR TO SEA FROM OVER CENTRAL NY STATE. AUTOPLT/PMS ENGAGED. AT APPROX XD15Z THE CREW NOTED THAT THE AUTOPLT WAS TURNING US VERY SLOWLY TO THE N AND WE WERE DIVERGING SLIGHTLY FROM COURSE. EMER WAS DECLARED WITH MSP CENTER! THE PLTS ATTEMPTED TO FLY THE ACFT WITH AUTOPLT AND MANUALLY WITH GREAT EFFORT; BUT TO NO AVAIL. WERE ABLE TO USE RUDDER AND DIFFERENTIAL THRUST AND SMALL AMOUNT OF SPOILER TO LEVEL WINGS. AFTER 10-15 MINS AND GOING THROUGH JAMMED CTLS PROC; PLTS USING 300-400 LBS PRESSURE BROKE CTLS FREE. WE CHOSE TO RETURN TO MSP AND LAND IN DAYLIGHT WITH VERY LITTLE XWIND. LNDG WAS UNEVENTFUL EXCEPT SPOILERS EXTENDED ONLY TO FLT DETENT. I COULD NOT PULL ANY FURTHER. ON GND FOUND ICE WATER FELL FROM 2 SMALL AIR CONDITIONING DRAIN PLUGS THAT HAD BEEN LEFT WITH CAPS OFF IN LEFT MAIN FUSELAGE GEAR WHEEL WELL. CAUSE: DRAIN PLUGS LEFT OPEN; SNOW LEFT UNDER CARGO PALLETS DRAINED INTO LEFT MAIN FUSELAGE WELL AND REFROZE OVER CTL CABLES. PREVENTION: GND CREW SHOULD ENSURE PLUGS ARE CLOSED ON AIR CONDITIONING DRAINS. ADDITIONAL CHK FROM AIRCREW MAYBE REQUIRED. REMOVE SNOW FROM CARGO DECK AND LNDG CREWS SHOULD CLEAR DECK BEFORE LOADING CARGO! PERMANENT FIX: REROUTE DRAINS; THEY ARE IN A BAD LOCATION!