Narrative:

First, I carry a squeegee, and squeegeed the windshield before the start sequence. Cleared to taxi, I taxied. I was changing the ground frequency in my #2 radio (because #1 radio was breaking up a little) and putting ATIS frequency into #1, but I was hit by fairly strong jetblast from the line of traffic holding, which changed my forward direction and also heavily refogged my plexiglas windscreen. I continued my taxi though, believing I was still correctly on course. The airplane was now pointed diagonally along the taxiway. At this point, I knew that something was amiss, but I mistakenly thought that I was right of course and turned somewhat left. Then I turned again to the right between 2 sets of blue taxiway lights, but the problem here was, I was on another part of the txwys than where I believed I was, and instead of turning down the taxiway, I turned between them and dropped the airplane into the ditch. Contributing factors: 1) the jetblast from the waiting heavy metal traffic. A) this turned my airplane's forward movement, and in low windshield visibility B) caused heavy fog to form on the windscreen. 2) I was busy in the cockpit a bit changing radio frequencys to the better radio while forces outside were changing my course. 3) my believing, in low visibility, that I was somewhere where I was not, and some overconfidence was factor, as I have flown this route 4 times per week, 2 round trips per night for 14 months and I've been along these txwys over 1000 times. Fixes might be: 1) green centerline taxiway lights (or even reflectors) along the diagonal taxiway. This particular taxiway is difficult to distinguish even on a clear night and a clear windshield this direction because of the high glare factor from lights to the north side of runway.

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Original NASA ASRS Text

Title: C310 PLT TAXIES INTO DITCH AFTER ENCOUNTERING JETBLAST AND FOGGING WINDOWS.

Narrative: FIRST, I CARRY A SQUEEGEE, AND SQUEEGEED THE WINDSHIELD BEFORE THE START SEQUENCE. CLRED TO TAXI, I TAXIED. I WAS CHANGING THE GND FREQ IN MY #2 RADIO (BECAUSE #1 RADIO WAS BREAKING UP A LITTLE) AND PUTTING ATIS FREQ INTO #1, BUT I WAS HIT BY FAIRLY STRONG JETBLAST FROM THE LINE OF TFC HOLDING, WHICH CHANGED MY FORWARD DIRECTION AND ALSO HEAVILY REFOGGED MY PLEXIGLAS WINDSCREEN. I CONTINUED MY TAXI THOUGH, BELIEVING I WAS STILL CORRECTLY ON COURSE. THE AIRPLANE WAS NOW POINTED DIAGONALLY ALONG THE TXWY. AT THIS POINT, I KNEW THAT SOMETHING WAS AMISS, BUT I MISTAKENLY THOUGHT THAT I WAS R OF COURSE AND TURNED SOMEWHAT L. THEN I TURNED AGAIN TO THE R BTWN 2 SETS OF BLUE TXWY LIGHTS, BUT THE PROB HERE WAS, I WAS ON ANOTHER PART OF THE TXWYS THAN WHERE I BELIEVED I WAS, AND INSTEAD OF TURNING DOWN THE TXWY, I TURNED BTWN THEM AND DROPPED THE AIRPLANE INTO THE DITCH. CONTRIBUTING FACTORS: 1) THE JETBLAST FROM THE WAITING HVY METAL TFC. A) THIS TURNED MY AIRPLANE'S FORWARD MOVEMENT, AND IN LOW WINDSHIELD VISIBILITY B) CAUSED HVY FOG TO FORM ON THE WINDSCREEN. 2) I WAS BUSY IN THE COCKPIT A BIT CHANGING RADIO FREQS TO THE BETTER RADIO WHILE FORCES OUTSIDE WERE CHANGING MY COURSE. 3) MY BELIEVING, IN LOW VISIBILITY, THAT I WAS SOMEWHERE WHERE I WAS NOT, AND SOME OVERCONFIDENCE WAS FACTOR, AS I HAVE FLOWN THIS RTE 4 TIMES PER WK, 2 ROUND TRIPS PER NIGHT FOR 14 MONTHS AND I'VE BEEN ALONG THESE TXWYS OVER 1000 TIMES. FIXES MIGHT BE: 1) GREEN CTRLINE TXWY LIGHTS (OR EVEN REFLECTORS) ALONG THE DIAGONAL TXWY. THIS PARTICULAR TXWY IS DIFFICULT TO DISTINGUISH EVEN ON A CLR NIGHT AND A CLR WINDSHIELD THIS DIRECTION BECAUSE OF THE HIGH GLARE FACTOR FROM LIGHTS TO THE N SIDE OF RWY.

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.