Narrative:

While on the el nido 3 arrival into sjc (HYP240047) we were given a heading from bay approach of 270 degrees to intercept the localizer runway 30L into sjc. Once established on the localizer runway 30L at 8000 ft the subsequent clearance was to 'maintain 8000 ft until gilro/5000 ft until klide cleared ILS runway 30L sjc.' the navigation #1 was on the ILS frequency and the navigation #2 was on sjc at the time. The captain was flying the aircraft and looked at the DME on navigation #2 and thought we were inside gilro and started down. At that time the first officer changed the navigation #2 to sau. When the sau DME came up, we realized we were approximately 1.5 mi outside gilro and stopped our descent at 7000 ft. The controller then queried us as to our understanding that our clearance was to cross gilro at 8000 ft. We apologized for the confusion and told him we were level at 7000 ft. He subsequently canceled our approach clearance and cleared us to maintain 7000 ft, which we did. The controller then pointed out some crossing traffic below us at 6000 ft and we responded we had that traffic in sight. We were again cleared the ILS runway 30L sjc for a normal approach and landing. Upon reflection we felt we had both receivers set appropriately for the initial clearance given. (Navigation #1 ILS/navigation #2 sjc). Upon receiving our subsequent clearance to cross gilro at 8000 ft klide at 5000 ft, etc, we had to switch the navigation #2 to sau in order to identify 66.6 DME for gilro. This changing of navigation frequencys led to our momentary confusion as to our position in relation to gilro and which navigation frequency we had set. A possible solution would be to indent gilro off of both sau and sjc on the approach chart.

Related reports:

Google
 

Original NASA ASRS Text

Title: MLG HAS ALTDEV WHEN TUNED TO WRONG VOR.

Narrative: WHILE ON THE EL NIDO 3 ARR INTO SJC (HYP240047) WE WERE GIVEN A HDG FROM BAY APCH OF 270 DEGS TO INTERCEPT THE LOC RWY 30L INTO SJC. ONCE ESTABLISHED ON THE LOC RWY 30L AT 8000 FT THE SUBSEQUENT CLRNC WAS TO 'MAINTAIN 8000 FT UNTIL GILRO/5000 FT UNTIL KLIDE CLRED ILS RWY 30L SJC.' THE NAV #1 WAS ON THE ILS FREQ AND THE NAV #2 WAS ON SJC AT THE TIME. THE CAPT WAS FLYING THE ACFT AND LOOKED AT THE DME ON NAV #2 AND THOUGHT WE WERE INSIDE GILRO AND STARTED DOWN. AT THAT TIME THE FO CHANGED THE NAV #2 TO SAU. WHEN THE SAU DME CAME UP, WE REALIZED WE WERE APPROX 1.5 MI OUTSIDE GILRO AND STOPPED OUR DSCNT AT 7000 FT. THE CTLR THEN QUERIED US AS TO OUR UNDERSTANDING THAT OUR CLRNC WAS TO CROSS GILRO AT 8000 FT. WE APOLOGIZED FOR THE CONFUSION AND TOLD HIM WE WERE LEVEL AT 7000 FT. HE SUBSEQUENTLY CANCELED OUR APCH CLRNC AND CLRED US TO MAINTAIN 7000 FT, WHICH WE DID. THE CTLR THEN POINTED OUT SOME XING TFC BELOW US AT 6000 FT AND WE RESPONDED WE HAD THAT TFC IN SIGHT. WE WERE AGAIN CLRED THE ILS RWY 30L SJC FOR A NORMAL APCH AND LNDG. UPON REFLECTION WE FELT WE HAD BOTH RECEIVERS SET APPROPRIATELY FOR THE INITIAL CLRNC GIVEN. (NAV #1 ILS/NAV #2 SJC). UPON RECEIVING OUR SUBSEQUENT CLRNC TO CROSS GILRO AT 8000 FT KLIDE AT 5000 FT, ETC, WE HAD TO SWITCH THE NAV #2 TO SAU IN ORDER TO IDENT 66.6 DME FOR GILRO. THIS CHANGING OF NAV FREQS LED TO OUR MOMENTARY CONFUSION AS TO OUR POS IN RELATION TO GILRO AND WHICH NAV FREQ WE HAD SET. A POSSIBLE SOLUTION WOULD BE TO INDENT GILRO OFF OF BOTH SAU AND SJC ON THE APCH CHART.

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.