Narrative:

Gso was recovering from a recent blizzard. We arrived in the late afternoon with temperature of 40 degrees F. Our cargo was delayed by bad road conditions so the aircraft was not loaded until two or so hours after sunset. We received taxi instructions via a taxiway that had been plowed, but unused, ground requested a braking action report. While the taxiway had been plowed, there was about 1 inch of hard-packed snow covering it. As we proceeded down the taxiway I felt the aircraft pull to the right, left turn commands with nosewheel steering were completely ineffectual as well as the limited differential power the engines produce in low (ground) RPM. I stopped the aircraft because it was headed for the edge of the taxiway. I then shifted the engines to normal (high) RPM where full power is available. After trying several methods (powering-out forward, maximum reverse differential power), it was obvious that we were stuck. This was hard to accept since we were dead center on the plowed taxiway. After contacting ground and requesting assistance, I pondered the predicament I was in. It became apparent that the taxiway was not plowed down the centerline, but about 15 ft or 20 ft right of center. Later inspection on the ground proved this to be so. The track of the right main tires showed that even though the aircraft was in the center of the plowed taxiway, the right main was never on the taxiway. The right side traveled over an area of gravel 'sub- straight' which supported the weight, but when the gravel ended, the underlying mud could not support the weight and that's where we stopped. Another factor was the taxiway was unsafe to walk on let alone taxi on. The hard packed snow had started to melt in the warmth of the day and refroze when the sun set making it a sheet of ice. The aircraft could not be extracted until the following day when the airport authority/authorized chemically deiced the taxiway. I am based in the great lakes area and I have flown in winter conditions all of my flying career. It never entered my mind that the taxiway would be plowed off center (now it will). This is a good example of the many 'traps' out waiting to get you.

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Original NASA ASRS Text

Title: ACFT FOLLOWS PLOWED TXWY ONLY TO GET STUCK IN THE MUD. TXWY PLOWING DOES NOT FOLLOW ACTUAL TXWY.

Narrative: GSO WAS RECOVERING FROM A RECENT BLIZZARD. WE ARRIVED IN THE LATE AFTERNOON WITH TEMP OF 40 DEGS F. OUR CARGO WAS DELAYED BY BAD ROAD CONDITIONS SO THE ACFT WAS NOT LOADED UNTIL TWO OR SO HRS AFTER SUNSET. WE RECEIVED TAXI INSTRUCTIONS VIA A TXWY THAT HAD BEEN PLOWED, BUT UNUSED, GND REQUESTED A BRAKING ACTION RPT. WHILE THE TXWY HAD BEEN PLOWED, THERE WAS ABOUT 1 INCH OF HARD-PACKED SNOW COVERING IT. AS WE PROCEEDED DOWN THE TXWY I FELT THE ACFT PULL TO THE R, L TURN COMMANDS WITH NOSEWHEEL STEERING WERE COMPLETELY INEFFECTUAL AS WELL AS THE LIMITED DIFFERENTIAL PWR THE ENGS PRODUCE IN LOW (GND) RPM. I STOPPED THE ACFT BECAUSE IT WAS HEADED FOR THE EDGE OF THE TXWY. I THEN SHIFTED THE ENGS TO NORMAL (HIGH) RPM WHERE FULL PWR IS AVAILABLE. AFTER TRYING SEVERAL METHODS (POWERING-OUT FORWARD, MAX REVERSE DIFFERENTIAL PWR), IT WAS OBVIOUS THAT WE WERE STUCK. THIS WAS HARD TO ACCEPT SINCE WE WERE DEAD CTR ON THE PLOWED TXWY. AFTER CONTACTING GND AND REQUESTING ASSISTANCE, I PONDERED THE PREDICAMENT I WAS IN. IT BECAME APPARENT THAT THE TXWY WAS NOT PLOWED DOWN THE CTRLINE, BUT ABOUT 15 FT OR 20 FT R OF CTR. LATER INSPECTION ON THE GND PROVED THIS TO BE SO. THE TRACK OF THE R MAIN TIRES SHOWED THAT EVEN THOUGH THE ACFT WAS IN THE CTR OF THE PLOWED TXWY, THE R MAIN WAS NEVER ON THE TXWY. THE R SIDE TRAVELED OVER AN AREA OF GRAVEL 'SUB- STRAIGHT' WHICH SUPPORTED THE WEIGHT, BUT WHEN THE GRAVEL ENDED, THE UNDERLYING MUD COULD NOT SUPPORT THE WEIGHT AND THAT'S WHERE WE STOPPED. ANOTHER FACTOR WAS THE TXWY WAS UNSAFE TO WALK ON LET ALONE TAXI ON. THE HARD PACKED SNOW HAD STARTED TO MELT IN THE WARMTH OF THE DAY AND REFROZE WHEN THE SUN SET MAKING IT A SHEET OF ICE. THE ACFT COULD NOT BE EXTRACTED UNTIL THE FOLLOWING DAY WHEN THE ARPT AUTH CHEMICALLY DEICED THE TXWY. I AM BASED IN THE GREAT LAKES AREA AND I HAVE FLOWN IN WINTER CONDITIONS ALL OF MY FLYING CAREER. IT NEVER ENTERED MY MIND THAT THE TXWY WOULD BE PLOWED OFF CTR (NOW IT WILL). THIS IS A GOOD EXAMPLE OF THE MANY 'TRAPS' OUT WAITING TO GET YOU.

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.