Narrative:

As we taxied clear of runway 26L at grr, we departed the taxiway into snow covered grass. The aircraft was shut down in the snow/grass and later removed via tow trucks. 5-8 inches of snow had fallen and we had to hold while the airport was closed for snow removal. We expected to see snow on txwys and ramps. There were numerous runway and taxiway closures and we had been advised of such. The airport operations in charge of snow removal suggested that the best taxi route to our FBO would be taxiway M then taxiway D then taxiway right. The wind was approximately 300 degrees at 20 KTS gusting to 30 KTS. Another factor was that at landing, although we found the runway to be nicely plowed, approximately 4500 ft down runway 26L on our right was an air carrier X erj in the grass. We had no idea that it would be there and although it was not a safety factor as far as its distance to the runway, it was a big distraction. A BE1900 commuter flight landed right before us. I wondered if this aircraft was that 1900 and that he had taxied into the grass after landing. The erj was pointed north (as in taxiing clear) and the interior lights were all on. The third and final factor was that the taxiway/runway lights and signs were confusing there at taxiway A2 and taxiway M. Taxiway A2 is a 'forward high speed.' it is rather filleted and the blue taxiway lights seem to start 'early' and then there are a bunch of them -- especially when adding in taxiway M. My recollection is seeing a taxiway A2 sign shortly after passing the erj. This was followed by seeing blue taxiway lights. We continued down the runway and were looking for taxiway M. I expected it to be plowed, but not necessarily 'clear' of snow. (Taxiway M basically heads you right towards the tower and rotating beacon.) I recall seeing an 'M/A2' sign. At this point, we thought we were on taxiway M since we could see parallel blue taxi lights in front of us. We taxied forward and when we discovered we were no longer on the pavement, we shut down the engines. Our proximity to the runway necessitated that runway 26L be closed until aircraft was moved. Although WX conditions were not ideal, this aircraft was crewed with 2 professional airmen. We were not tired or rushed, but were distraction by the erj. I believe this should have been available information. The signs and lights, along with the WX (specifically the snow), led us to agree that we were at a position that we really weren't at. The aircraft incurred no damage and the crew/passenger were not injured.

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Original NASA ASRS Text

Title: FLT CREW OF C560 TAXIED OFF PAVED SURFACE AFTER EXITING RWY. THE ACTIVE RWY WAS CLOSED AS A RESULT OF THE RPTR'S ACFT'S PROX.

Narrative: AS WE TAXIED CLR OF RWY 26L AT GRR, WE DEPARTED THE TXWY INTO SNOW COVERED GRASS. THE ACFT WAS SHUT DOWN IN THE SNOW/GRASS AND LATER REMOVED VIA TOW TRUCKS. 5-8 INCHES OF SNOW HAD FALLEN AND WE HAD TO HOLD WHILE THE ARPT WAS CLOSED FOR SNOW REMOVAL. WE EXPECTED TO SEE SNOW ON TXWYS AND RAMPS. THERE WERE NUMEROUS RWY AND TXWY CLOSURES AND WE HAD BEEN ADVISED OF SUCH. THE ARPT OPS IN CHARGE OF SNOW REMOVAL SUGGESTED THAT THE BEST TAXI RTE TO OUR FBO WOULD BE TXWY M THEN TXWY D THEN TXWY R. THE WIND WAS APPROX 300 DEGS AT 20 KTS GUSTING TO 30 KTS. ANOTHER FACTOR WAS THAT AT LNDG, ALTHOUGH WE FOUND THE RWY TO BE NICELY PLOWED, APPROX 4500 FT DOWN RWY 26L ON OUR R WAS AN ACR X ERJ IN THE GRASS. WE HAD NO IDEA THAT IT WOULD BE THERE AND ALTHOUGH IT WAS NOT A SAFETY FACTOR AS FAR AS ITS DISTANCE TO THE RWY, IT WAS A BIG DISTR. A BE1900 COMMUTER FLT LANDED RIGHT BEFORE US. I WONDERED IF THIS ACFT WAS THAT 1900 AND THAT HE HAD TAXIED INTO THE GRASS AFTER LNDG. THE ERJ WAS POINTED N (AS IN TAXIING CLR) AND THE INTERIOR LIGHTS WERE ALL ON. THE THIRD AND FINAL FACTOR WAS THAT THE TXWY/RWY LIGHTS AND SIGNS WERE CONFUSING THERE AT TXWY A2 AND TXWY M. TXWY A2 IS A 'FORWARD HIGH SPD.' IT IS RATHER FILLETED AND THE BLUE TXWY LIGHTS SEEM TO START 'EARLY' AND THEN THERE ARE A BUNCH OF THEM -- ESPECIALLY WHEN ADDING IN TXWY M. MY RECOLLECTION IS SEEING A TXWY A2 SIGN SHORTLY AFTER PASSING THE ERJ. THIS WAS FOLLOWED BY SEEING BLUE TXWY LIGHTS. WE CONTINUED DOWN THE RWY AND WERE LOOKING FOR TXWY M. I EXPECTED IT TO BE PLOWED, BUT NOT NECESSARILY 'CLR' OF SNOW. (TXWY M BASICALLY HEADS YOU RIGHT TOWARDS THE TWR AND ROTATING BEACON.) I RECALL SEEING AN 'M/A2' SIGN. AT THIS POINT, WE THOUGHT WE WERE ON TXWY M SINCE WE COULD SEE PARALLEL BLUE TAXI LIGHTS IN FRONT OF US. WE TAXIED FORWARD AND WHEN WE DISCOVERED WE WERE NO LONGER ON THE PAVEMENT, WE SHUT DOWN THE ENGS. OUR PROX TO THE RWY NECESSITATED THAT RWY 26L BE CLOSED UNTIL ACFT WAS MOVED. ALTHOUGH WX CONDITIONS WERE NOT IDEAL, THIS ACFT WAS CREWED WITH 2 PROFESSIONAL AIRMEN. WE WERE NOT TIRED OR RUSHED, BUT WERE DISTR BY THE ERJ. I BELIEVE THIS SHOULD HAVE BEEN AVAILABLE INFO. THE SIGNS AND LIGHTS, ALONG WITH THE WX (SPECIFICALLY THE SNOW), LED US TO AGREE THAT WE WERE AT A POS THAT WE REALLY WEREN'T AT. THE ACFT INCURRED NO DAMAGE AND THE CREW/PAX WERE NOT INJURED.

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.