Narrative:

Quick repo flight to rdu. We picked up the aircraft from maintenance. Our departure clearance was 'radar vectors to lwood then as filed.' we plugged it in the FMS and verified the route. In flight; after departure; a few minutes into the flight; the controller assigns us 'direct to lwood'. As I am trying to hit direct; the FMS doesn't pull up lwood anymore. We assume it dropped out so we manually plugged it back in and hit direct and navigation and the aircraft turned to lwood. A few moments later the controller; fairly alarmed asked us where we were navigating towards and that we needed to make an immediate 180 degree turn to lwood. At this moment we realized our mfds were showing a dr icon. We confirmed the spelling of lwood and that that's where we were navigating to; but asked him for vectors to rdu. He assigned us to intercept the 082 from [departure airport] which we did in green needles. The FMS needles were showing opposite directions and nowhere near [our location]. So we stayed in green needles until we landed in raleigh. On the ground we called maintenance and reset the FMS; and re initialized our position. Eventually it all went back to normal. We flew two more legs without further issues. We relied too much on the box to be correct that we didn't realize our GPS was not working correctly. Keeping situational awareness at all times will avoid situations like that. I am glad the controller noticed right at the same time we did; so we could correct that error.

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Original NASA ASRS Text

Title: A CL300 pilot experienced a track deviation after departure when cleared direct to LWOOD. It was noticed too late that the FMS was in DR mode due to the GPS not operating correctly. ATC issued a vector and the crew navigated to RDU in Green Needles. Maintenance reset the FMS; and re-initialized the position after several attempts.

Narrative: Quick repo flight to RDU. We picked up the aircraft from Maintenance. Our departure clearance was 'radar vectors to LWOOD then as filed.' We plugged it in the FMS and verified the route. In flight; after departure; a few minutes into the flight; the controller assigns us 'direct to LWOOD'. As I am trying to hit DIRECT; the FMS doesn't pull up LWOOD anymore. We assume it dropped out so we manually plugged it back in and hit DIRECT and NAV and the aircraft turned to LWOOD. A few moments later the controller; fairly alarmed asked us where we were navigating towards and that we needed to make an immediate 180 degree turn to LWOOD. At this moment we realized our MFDs were showing a DR icon. We confirmed the spelling of LWOOD and that that's where we were navigating to; but asked him for vectors to RDU. He assigned us to intercept the 082 from [departure airport] which we did in green needles. The FMS needles were showing opposite directions and nowhere near [our location]. So we stayed in green needles until we landed in Raleigh. On the ground we called Maintenance and reset the FMS; and re initialized our position. Eventually it all went back to normal. We flew two more legs without further issues. We relied too much on the box to be correct that we didn't realize our GPS was not working correctly. Keeping situational awareness at all times will avoid situations like that. I am glad the controller noticed right at the same time we did; so we could correct that error.

Data retrieved from NASA's ASRS site 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.