Narrative:

Location: southwest of irk VOR. We were navigating using the GPS. After crossing irk and beginning the braymer 1 arrival, I noticed that we were right of course and heading approximately 20 degrees to the right of the arrival radial. I pointed this out to the captain who turned the aircraft back to the left to rejoin the arrival. While we were turning ATC asked if we were deviation. I said that there was a problem with the GPS and that we were turning left to rejoin the arrival. The controller acknowledged and the remainder of the flight was uneventful.

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Original NASA ASRS Text

Title: AN INITIAL HDG TRACK DEV IS CORRECTED WHEN THE FO ADVISES THE PIC THAT THERE WAS A PROB WITH THE GPS NAV SYS SW OF IRK, MO.

Narrative: LOCATION: SW OF IRK VOR. WE WERE NAVING USING THE GPS. AFTER XING IRK AND BEGINNING THE BRAYMER 1 ARR, I NOTICED THAT WE WERE R OF COURSE AND HDG APPROX 20 DEGS TO THE R OF THE ARR RADIAL. I POINTED THIS OUT TO THE CAPT WHO TURNED THE ACFT BACK TO THE L TO REJOIN THE ARR. WHILE WE WERE TURNING ATC ASKED IF WE WERE DEV. I SAID THAT THERE WAS A PROB WITH THE GPS AND THAT WE WERE TURNING L TO REJOIN THE ARR. THE CTLR ACKNOWLEDGED AND THE REMAINDER OF THE FLT WAS UNEVENTFUL.

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.