Narrative:

Using RNAV to establish oliva intersection, was cleared to descend upon reaching sgf VORTAC. RNAV showed passage of oliva intersection and shortly thereafter passage of sgf VORTAC. Started descent to cleared altitude of 2700 MSL, reported sgf. Upon setting up second navigation for check of VOR runway 20 approach, second navigation showed outside VOR. RNAV unit had failed. Immediately climbed to 3000 (MEA and MSA). Reported RNAV failure to sgf approach, cleared to intercept 014 radial and track inbound. In confusion, understood and repeated as 140 radial. Passed through 014 radial before again asking how I could intercept the 140 eastbound north of VOR. Cleared to track inbound to sgf on 030 radial. Rest uneventful. (Approach radar OTS). Corrections: be more alert when equipment failure occurs.

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Original NASA ASRS Text

Title: SMA PLT HAS RNAV GIVING INCORRECT POS. DSNDS, THEN ON XCHK REALIZES ERROR. RECEIVES VECTORS, TRANSPOSES HDG NUMBERS, MORE VECTORS.

Narrative: USING RNAV TO ESTABLISH OLIVA INTXN, WAS CLRED TO DSND UPON REACHING SGF VORTAC. RNAV SHOWED PASSAGE OF OLIVA INTXN AND SHORTLY THEREAFTER PASSAGE OF SGF VORTAC. STARTED DSCNT TO CLRED ALT OF 2700 MSL, RPTED SGF. UPON SETTING UP SECOND NAV FOR CHK OF VOR RWY 20 APCH, SECOND NAV SHOWED OUTSIDE VOR. RNAV UNIT HAD FAILED. IMMEDIATELY CLBED TO 3000 (MEA AND MSA). RPTED RNAV FAILURE TO SGF APCH, CLRED TO INTERCEPT 014 RADIAL AND TRACK INBOUND. IN CONFUSION, UNDERSTOOD AND REPEATED AS 140 RADIAL. PASSED THROUGH 014 RADIAL BEFORE AGAIN ASKING HOW I COULD INTERCEPT THE 140 EBOUND N OF VOR. CLRED TO TRACK INBOUND TO SGF ON 030 RADIAL. REST UNEVENTFUL. (APCH RADAR OTS). CORRECTIONS: BE MORE ALERT WHEN EQUIP FAILURE OCCURS.

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.