Narrative:

When I started engines for a trip under far part 135, the pilot's side horizon was slow to erect. In the right seat there was a pilot rated non revenue/non passenger that was monitoring and tuning radios. This is part of the training in the flight program. While that person performs some of the communications, it is still the direct responsibility of the PIC. We obtained the current ATIS which indicated 100 ft over with 1/2 mi visibility. As we taxied out, I was concentrating on the gyro and thinking about whether or not the flight could continue. The gyro had stabilized, but I briefed the right seat passenger on the actions we would take if the gyro subsequently failed. During this time, a new ATIS was issued and the ground controller came on the frequency and said something to the effect 'the new ATIS is in effect, altimeter XXXX, everything else is the same.' we then were cleared for takeoff and departed without incident. As we were climbing out, there was a nagging notion in my mind that I may have missed something in the xmissions. I asked the right seat passenger what the controller had said about visibility, and she replied that the message had been 'visibility holding steady at 1/4, new altimeter is XXXX, everything else is the same.' because of my attention being directed to the slow gyro, looking at the options, and deciding on a course of action both with the gyro operational and if it should fail, I was not really 'listening' to the controller. Then, when I heard the altimeter setting and the phrase that 'everything else is the same,' I set the altimeter and pressed on. Only after everything was stable and routine did I play back the preceding events and realize I had missed the decrease in visibility, which was below our takeoff minimums.

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Original NASA ASRS Text

Title: AN ATX PLT PERFORMS A TKOF DURING WX CONDITIONS THAT MADE THAT OP ILLEGAL AT DBQ, IA.

Narrative: WHEN I STARTED ENGS FOR A TRIP UNDER FAR PART 135, THE PLT'S SIDE HORIZON WAS SLOW TO ERECT. IN THE R SEAT THERE WAS A PLT RATED NON REVENUE/NON PAX THAT WAS MONITORING AND TUNING RADIOS. THIS IS PART OF THE TRAINING IN THE FLT PROGRAM. WHILE THAT PERSON PERFORMS SOME OF THE COMS, IT IS STILL THE DIRECT RESPONSIBILITY OF THE PIC. WE OBTAINED THE CURRENT ATIS WHICH INDICATED 100 FT OVER WITH 1/2 MI VISIBILITY. AS WE TAXIED OUT, I WAS CONCENTRATING ON THE GYRO AND THINKING ABOUT WHETHER OR NOT THE FLT COULD CONTINUE. THE GYRO HAD STABILIZED, BUT I BRIEFED THE R SEAT PAX ON THE ACTIONS WE WOULD TAKE IF THE GYRO SUBSEQUENTLY FAILED. DURING THIS TIME, A NEW ATIS WAS ISSUED AND THE GND CTLR CAME ON THE FREQ AND SAID SOMETHING TO THE EFFECT 'THE NEW ATIS IS IN EFFECT, ALTIMETER XXXX, EVERYTHING ELSE IS THE SAME.' WE THEN WERE CLRED FOR TKOF AND DEPARTED WITHOUT INCIDENT. AS WE WERE CLBING OUT, THERE WAS A NAGGING NOTION IN MY MIND THAT I MAY HAVE MISSED SOMETHING IN THE XMISSIONS. I ASKED THE R SEAT PAX WHAT THE CTLR HAD SAID ABOUT VISIBILITY, AND SHE REPLIED THAT THE MESSAGE HAD BEEN 'VISIBILITY HOLDING STEADY AT 1/4, NEW ALTIMETER IS XXXX, EVERYTHING ELSE IS THE SAME.' BECAUSE OF MY ATTN BEING DIRECTED TO THE SLOW GYRO, LOOKING AT THE OPTIONS, AND DECIDING ON A COURSE OF ACTION BOTH WITH THE GYRO OPERATIONAL AND IF IT SHOULD FAIL, I WAS NOT REALLY 'LISTENING' TO THE CTLR. THEN, WHEN I HEARD THE ALTIMETER SETTING AND THE PHRASE THAT 'EVERYTHING ELSE IS THE SAME,' I SET THE ALTIMETER AND PRESSED ON. ONLY AFTER EVERYTHING WAS STABLE AND ROUTINE DID I PLAY BACK THE PRECEDING EVENTS AND REALIZE I HAD MISSED THE DECREASE IN VISIBILITY, WHICH WAS BELOW OUR TKOF MINIMUMS.

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.