|37000 Feet||Browse and search NASA's
Aviation Safety Reporting System
|Locale Reference||navaid : coy.vor|
|Altitude||msl single value : 7000|
|Controlling Facilities||artcc : zsu.artcc|
|Operator||common carrier : air carrier|
|Make Model Name||Commercial Fixed Wing|
|Operating Under FAR Part||Part 121|
|Navigation In Use||other vortac|
|Flight Phase||cruise : enroute altitude change|
|Route In Use||enroute : direct|
|Affiliation||company : air carrier|
|Function||flight crew : captain|
oversight : pic
|Qualification||pilot : commercial|
|Anomaly||other spatial deviation|
|Resolutory Action||flight crew : returned to intended or assigned course|
|Consequence||faa : reviewed incident with flight crew|
|Problem Areas||Navigational Facility|
|Primary Problem||Navigational Facility|
Cleared direct st croix VOR -- 76 NM (7000 ft cruise) 134 radial inbound; needle initially centered. Proceeded to go full scale left (north) of course. After a few seconds went full scale to 1 DOT right (south) of course. Approximately 60 miles from VOR stayed within 1/4 DOT -- 1 full DOT deviations then centered. Continued minor deviations (1/2 DOT to 1 DOT) until approach into stx. We asked ATC to verify our position (direct stx). Our heading was correct but the CDI wasn't centered. It was 1/2 DOT off to the south. St croix VOR is very unreliable at any distance.
Original NASA ASRS Text
Title: AN ACR PILOT REPORTS THE STX VOR BEARING SIGNALS ARE UNRELIABLE AND FLUCTUATE EXCESSIVELY.
Narrative: CLRED DIRECT ST CROIX VOR -- 76 NM (7000 FT CRUISE) 134 RADIAL INBOUND; NEEDLE INITIALLY CENTERED. PROCEEDED TO GO FULL SCALE LEFT (NORTH) OF COURSE. AFTER A FEW SECONDS WENT FULL SCALE TO 1 DOT RIGHT (SOUTH) OF COURSE. APPROX 60 MILES FROM VOR STAYED WITHIN 1/4 DOT -- 1 FULL DOT DEVIATIONS THEN CENTERED. CONTINUED MINOR DEVIATIONS (1/2 DOT TO 1 DOT) UNTIL APCH INTO STX. WE ASKED ATC TO VERIFY OUR POSITION (DIRECT STX). OUR HDG WAS CORRECT BUT THE CDI WASN'T CENTERED. IT WAS 1/2 DOT OFF TO THE SOUTH. ST CROIX VOR IS VERY UNRELIABLE AT ANY DISTANCE.
Data retrieved from NASA's ASRS site as of January 2009 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.