Narrative:

Shortly after takeoff, we got an FMS or error message. Just after being handed off to louisville approach we were given holding instruction at nabb VOR. The captain entered holding instructions on the FMS. We proceeded to fly direct to nabb via the FMS. When we approached the fix, we requested 13000 ft to get out of the WX for smoother air. Center said negative, and by the way, you are 10 mi north of nabb, please turn to nabb and hold as instructed. It turns out our FMS was over 10 mi off. We immediately switched to VOR navigation, flew direct to nabb and we began to hold. We reinitialized the FMS at that point. The lesson for us was to identify the problem sooner, switch to VOR and not rely on the FMS. I think we were caught up with the events of the day, which involved bad WX in cvg which caused us to divert to sdf. A 2 hour delay at sdf and more WX which caused more delays and the hold at nabb. Also, I see that we trust the FMS too much and assumed that the error was a glitch because the FMS routing looked good, which lulled us into complacency.

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Original NASA ASRS Text

Title: A CHALLENGER FLC RECEIVED AN FMS ERROR MESSAGE SHORTLY AFTER TKOF AND WERE UNABLE TO NAV TO A VOR NEAR LOU.

Narrative: SHORTLY AFTER TKOF, WE GOT AN FMS OR ERROR MESSAGE. JUST AFTER BEING HANDED OFF TO LOUISVILLE APCH WE WERE GIVEN HOLDING INSTRUCTION AT NABB VOR. THE CAPT ENTERED HOLDING INSTRUCTIONS ON THE FMS. WE PROCEEDED TO FLY DIRECT TO NABB VIA THE FMS. WHEN WE APCHED THE FIX, WE REQUESTED 13000 FT TO GET OUT OF THE WX FOR SMOOTHER AIR. CTR SAID NEGATIVE, AND BY THE WAY, YOU ARE 10 MI N OF NABB, PLEASE TURN TO NABB AND HOLD AS INSTRUCTED. IT TURNS OUT OUR FMS WAS OVER 10 MI OFF. WE IMMEDIATELY SWITCHED TO VOR NAV, FLEW DIRECT TO NABB AND WE BEGAN TO HOLD. WE REINITIALIZED THE FMS AT THAT POINT. THE LESSON FOR US WAS TO IDENT THE PROB SOONER, SWITCH TO VOR AND NOT RELY ON THE FMS. I THINK WE WERE CAUGHT UP WITH THE EVENTS OF THE DAY, WHICH INVOLVED BAD WX IN CVG WHICH CAUSED US TO DIVERT TO SDF. A 2 HR DELAY AT SDF AND MORE WX WHICH CAUSED MORE DELAYS AND THE HOLD AT NABB. ALSO, I SEE THAT WE TRUST THE FMS TOO MUCH AND ASSUMED THAT THE ERROR WAS A GLITCH BECAUSE THE FMS ROUTING LOOKED GOOD, WHICH LULLED US INTO COMPLACENCY.

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.