Narrative:

On arrival at bitta at XA00Z, I was cleared by hnl center to fly direct kokohead direct hnl. At this time my VOR signals were inadequate for navigation, so I proceeded direct kokohead utilizing my dual omega systems which both read the same course. Shortly thereafter the center controller informed me that I was on an incorrect course for kokohead and gave me a radar vector for a right intercept and a clearance to kokohead via maggi intersection direct kokohead. I plotted my bearing from kokohead VOR as soon as signals were reliable and confirmed her assessment. She also informed me that, at the time of my position report at bitta, I was in fact 20 mi northwest of bitta, but I had no way of confirming this observation. Overhead kokohead I noted the position readout of both omega system and took a photograph of both. Check N21.16.1, omega #1 north 21.03.7, #2 north 21.03.6--difference 12.4. West 157.42.3, west 157.27.7, 2 157.27.5--difference 14.6. On test, both omega systems showed no other faults. I concluded that both omegas had skipped a lane and I informed maintenance accordingly by write up in the maintenance log. Omega NOTAMS mentioned the existence of polar cap disturbance. Callback conversation with reporter revealed the following: position check over bebop had been right on. FAA did not take any action on the incident and the only discussion was with the controller. Was not aware of any loss of sep. Maintenance cleaned points on both units and apparently that solved the problem. Reporter flew the aircraft on the return flight and both units worked ok.

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Original NASA ASRS Text

Title: 20 MILES NORTH OF TRACK WHEN CHECKING IN WITH ZHN. BOTH OMEGA NAVIGATION UNITS IN ERROR SAME DISTANCE.

Narrative: ON ARR AT BITTA AT XA00Z, I WAS CLRED BY HNL CENTER TO FLY DIRECT KOKOHEAD DIRECT HNL. AT THIS TIME MY VOR SIGNALS WERE INADEQUATE FOR NAV, SO I PROCEEDED DIRECT KOKOHEAD UTILIZING MY DUAL OMEGA SYSTEMS WHICH BOTH READ THE SAME COURSE. SHORTLY THEREAFTER THE CENTER CTLR INFORMED ME THAT I WAS ON AN INCORRECT COURSE FOR KOKOHEAD AND GAVE ME A RADAR VECTOR FOR A R INTERCEPT AND A CLRNC TO KOKOHEAD VIA MAGGI INTXN DIRECT KOKOHEAD. I PLOTTED MY BEARING FROM KOKOHEAD VOR AS SOON AS SIGNALS WERE RELIABLE AND CONFIRMED HER ASSESSMENT. SHE ALSO INFORMED ME THAT, AT THE TIME OF MY POS RPT AT BITTA, I WAS IN FACT 20 MI NW OF BITTA, BUT I HAD NO WAY OF CONFIRMING THIS OBSERVATION. OVERHEAD KOKOHEAD I NOTED THE POS READOUT OF BOTH OMEGA SYS AND TOOK A PHOTOGRAPH OF BOTH. CHK N21.16.1, OMEGA #1 N 21.03.7, #2 N 21.03.6--DIFFERENCE 12.4. W 157.42.3, W 157.27.7, 2 157.27.5--DIFFERENCE 14.6. ON TEST, BOTH OMEGA SYSTEMS SHOWED NO OTHER FAULTS. I CONCLUDED THAT BOTH OMEGAS HAD SKIPPED A LANE AND I INFORMED MAINT ACCORDINGLY BY WRITE UP IN THE MAINT LOG. OMEGA NOTAMS MENTIONED THE EXISTENCE OF POLAR CAP DISTURBANCE. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING: POS CHK OVER BEBOP HAD BEEN RIGHT ON. FAA DID NOT TAKE ANY ACTION ON THE INCIDENT AND THE ONLY DISCUSSION WAS WITH THE CTLR. WAS NOT AWARE OF ANY LOSS OF SEP. MAINT CLEANED POINTS ON BOTH UNITS AND APPARENTLY THAT SOLVED THE PROB. RPTR FLEW THE ACFT ON THE RETURN FLT AND BOTH UNITS WORKED OK.

Data retrieved from NASA's ASRS site as of August 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.