Narrative:

Controller kept insisting that we were east of course when we were indeed west of course as requested and approved to deviate for WX. First officer and I confirmed position by use of raw data from bag VOR that showed us 330 degree radial west of 346 degree radial inbound on UL795. Controller confirmed this position and confirmed that he had us on radar contact but kept insisting that we were east of course, not west. Our final confirmation with controller had us on 275 degree radial, 30 DME west of bag when he turned us over to next controller. For about 20 mins the controller verified and confirmed that we were right of course but insisted that we were east, not west. He even inquired as to the status of our navaids which were all in working order. Our position was verified by crew as west by all available navaids and FMS. Supplemental information from acn 605413: location: inbound to bag VOR. En route, aircraft position discrepancy with brasilia center. After returning to the cockpit from my rest period, I was informed by the first officer and relief pilot that they had a position discrepancy with the brasilia center. We were approaching bag VOR from mia to gru and had requested deviation to the right of course for WX. After a while the controller asked why we were east of the course. Both my coplts said we were west of course and had deviated to the right of course. He acknowledged we were right of course but insisted that was east and not west. The controller asked if our navigation equipment was ok. My 2 coplts verified FMC position and inbound radials to bag VOR and indicated we were west of the airway, all was normal. After clear of the WX they proceeded direct to the next waypoint.

Google
 

Original NASA ASRS Text

Title: AFTER DEVIATING AROUND WX, A B767 CREW INBOUND TO SBGR FROM MIA ARE NOTIFIED BY SBGR ARTCC THAT THE FLT WAS E OF COURSE AND THE CREW INSISTED THEY WERE W.

Narrative: CTLR KEPT INSISTING THAT WE WERE E OF COURSE WHEN WE WERE INDEED W OF COURSE AS REQUESTED AND APPROVED TO DEVIATE FOR WX. FO AND I CONFIRMED POS BY USE OF RAW DATA FROM BAG VOR THAT SHOWED US 330 DEG RADIAL W OF 346 DEG RADIAL INBOUND ON UL795. CTLR CONFIRMED THIS POS AND CONFIRMED THAT HE HAD US ON RADAR CONTACT BUT KEPT INSISTING THAT WE WERE E OF COURSE, NOT W. OUR FINAL CONFIRMATION WITH CTLR HAD US ON 275 DEG RADIAL, 30 DME W OF BAG WHEN HE TURNED US OVER TO NEXT CTLR. FOR ABOUT 20 MINS THE CTLR VERIFIED AND CONFIRMED THAT WE WERE R OF COURSE BUT INSISTED THAT WE WERE E, NOT W. HE EVEN INQUIRED AS TO THE STATUS OF OUR NAVAIDS WHICH WERE ALL IN WORKING ORDER. OUR POS WAS VERIFIED BY CREW AS W BY ALL AVAILABLE NAVAIDS AND FMS. SUPPLEMENTAL INFO FROM ACN 605413: LOCATION: INBOUND TO BAG VOR. ENRTE, ACFT POS DISCREPANCY WITH BRASILIA CTR. AFTER RETURNING TO THE COCKPIT FROM MY REST PERIOD, I WAS INFORMED BY THE FO AND RELIEF PLT THAT THEY HAD A POS DISCREPANCY WITH THE BRASILIA CTR. WE WERE APCHING BAG VOR FROM MIA TO GRU AND HAD REQUESTED DEV TO THE R OF COURSE FOR WX. AFTER A WHILE THE CTLR ASKED WHY WE WERE E OF THE COURSE. BOTH MY COPLTS SAID WE WERE W OF COURSE AND HAD DEVIATED TO THE R OF COURSE. HE ACKNOWLEDGED WE WERE R OF COURSE BUT INSISTED THAT WAS E AND NOT W. THE CTLR ASKED IF OUR NAV EQUIP WAS OK. MY 2 COPLTS VERIFIED FMC POS AND INBOUND RADIALS TO BAG VOR AND INDICATED WE WERE W OF THE AIRWAY, ALL WAS NORMAL. AFTER CLR OF THE WX THEY PROCEEDED DIRECT TO THE NEXT WAYPOINT.

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.