Narrative:

ATC facility: lga tower. Location: northeast end of runway 4. Landing lga at late night, maximum landing weight, WX 200 ft, WX at minimums, braking action reported fair. Plowing in progress. Asked tower to report runway clear of equipment. Equipment reported clear when we were around 500 ft. Broke out at 300 ft. Runway half plowed. Right half plowed left half not plowed. Used maximum reverse and heavy braking. Found braking action poor. Slowed to taxi speed approximately 1000 ft from end. Only 1 runway exit plowed. Began turn onto exit. Immediately realized that plowed exit was not a taxiway but too late to turn back onto runway. Mains remained on runway nosewheel approximately 10 ft onto paved and plowed vehicle road. Called for tug and informed tower that we were not clear. Full responsibility for error is mine however incorrect decision influenced by the fact that roadway was the only plowed and only visible exit. Runway plowed only on right half had the effect on braking of no plowing at all since the left mains were braking in several inches of wet snow and slush with very little braking action. Each time the anti-skid released on the left there was a corresponding release on the right. Suggest that it would be safer if tower closed the runway until plowing is complete. Although the access road seemed passable to the parallel taxiway we resisted the strong urge to continue on it once the error was realized.

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Original NASA ASRS Text

Title: ACFT ATTEMPTED TO EXIT RWY ONTO ACCESS ROAD.

Narrative: ATC FACILITY: LGA TWR. LOCATION: NE END OF RWY 4. LNDG LGA AT LATE NIGHT, MAX LNDG WT, WX 200 FT, WX AT MINIMUMS, BRAKING ACTION RPTED FAIR. PLOWING IN PROGRESS. ASKED TWR TO RPT RWY CLR OF EQUIP. EQUIP RPTED CLR WHEN WE WERE AROUND 500 FT. BROKE OUT AT 300 FT. RWY HALF PLOWED. R HALF PLOWED L HALF NOT PLOWED. USED MAX REVERSE AND HVY BRAKING. FOUND BRAKING ACTION POOR. SLOWED TO TAXI SPD APPROX 1000 FT FROM END. ONLY 1 RWY EXIT PLOWED. BEGAN TURN ONTO EXIT. IMMEDIATELY REALIZED THAT PLOWED EXIT WAS NOT A TXWY BUT TOO LATE TO TURN BACK ONTO RWY. MAINS REMAINED ON RWY NOSEWHEEL APPROX 10 FT ONTO PAVED AND PLOWED VEHICLE ROAD. CALLED FOR TUG AND INFORMED TWR THAT WE WERE NOT CLR. FULL RESPONSIBILITY FOR ERROR IS MINE HOWEVER INCORRECT DECISION INFLUENCED BY THE FACT THAT ROADWAY WAS THE ONLY PLOWED AND ONLY VISIBLE EXIT. RWY PLOWED ONLY ON R HALF HAD THE EFFECT ON BRAKING OF NO PLOWING AT ALL SINCE THE L MAINS WERE BRAKING IN SEVERAL INCHES OF WET SNOW AND SLUSH WITH VERY LITTLE BRAKING ACTION. EACH TIME THE ANTI-SKID RELEASED ON THE L THERE WAS A CORRESPONDING RELEASE ON THE R. SUGGEST THAT IT WOULD BE SAFER IF TWR CLOSED THE RWY UNTIL PLOWING IS COMPLETE. ALTHOUGH THE ACCESS ROAD SEEMED PASSABLE TO THE PARALLEL TXWY WE RESISTED THE STRONG URGE TO CONTINUE ON IT ONCE THE ERROR WAS REALIZED.

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.