Narrative:

Prior to approach or downwind, discussion took place as to how this approach might be flown on computer data and how to build this approach. I concluded it could not be done. I chose not to occupy my hand flying with distractions as we had begun descent out of 10,000'. While maneuvering to a downwind, IFR, the captain was busy at the FMC and we had lots of time, in addition to an occasional radio call and monitoring my flying. We were given a turn to a right base and were receiving vectors to the final approach course with a clearance to intercept the localizer and fly the lda approach. The captain commented that he 'had the approach on the computer'. I switched to 'map' for a look (raw data in view in FD display, both localizer and GS). It looked good, but I had no time to check it. I failed to see the angle to the runway was wrong, he had a straight in final. I failed to note the localizer display moving slowly from left to right as we flew through the localizer. (Approach mode of FD was armed and captured with an appropriate lateral command.) when I noticed the full deflection right and the approach course on the map way to the left, I commented that 'something is wrong'. The controller queried us if we had the localizer ok and reiterated the frequency which we both immediately checked. Controller stated he 'had us left of course and to turn right to a new intercept heading of 170?' the captain had indicated to ATC 'we had a discrepancy, and to keep us advised of our progress'. I commented that the raw data agreed with the controller but the heading would never take us on an intercept with the map course. The controller was very helpful and said we 'were in good shape and approaching the localizer'. The captain was lost in the problem so I reached down and put my display back on full-up compass rose ILS mode. I concurred with the controller and concluded the captain's approach had led me astray and that I was staying on raw data. This leg I was 100% raw data and went to the 'computer map' for a look at the absolute wrong time. The captain was confused at this point and I was now back on the approach with raw data, I could not get him to abandon the computer. I called out glide slope moving, intercept, and glide slope high as I stated I would not descend below 3000' unless he was sure of where we were also. He concurred. The captain recognizing my calls quickly got on raw data and commanded me to descend which I did at about 1200 FPM. We proceeded and I stated that if we did not break out visually or capture the glide slope at a comfortable altitude for maneuvering, I would execute a go around. Captain agreed. We broke out about 900' on the localizer as we caught the glide slope and were in a comfortable position for the turn to final with a safe uneventful and smooth landing.

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Original NASA ASRS Text

Title: TRACK DEVIATION.

Narrative: PRIOR TO APCH OR DOWNWIND, DISCUSSION TOOK PLACE AS TO HOW THIS APCH MIGHT BE FLOWN ON COMPUTER DATA AND HOW TO BUILD THIS APCH. I CONCLUDED IT COULD NOT BE DONE. I CHOSE NOT TO OCCUPY MY HAND FLYING WITH DISTRACTIONS AS WE HAD BEGUN DSCNT OUT OF 10,000'. WHILE MANEUVERING TO A DOWNWIND, IFR, THE CAPT WAS BUSY AT THE FMC AND WE HAD LOTS OF TIME, IN ADDITION TO AN OCCASIONAL RADIO CALL AND MONITORING MY FLYING. WE WERE GIVEN A TURN TO A RIGHT BASE AND WERE RECEIVING VECTORS TO THE FINAL APCH COURSE WITH A CLRNC TO INTERCEPT THE LOC AND FLY THE LDA APCH. THE CAPT COMMENTED THAT HE 'HAD THE APCH ON THE COMPUTER'. I SWITCHED TO 'MAP' FOR A LOOK (RAW DATA IN VIEW IN FD DISPLAY, BOTH LOC AND GS). IT LOOKED GOOD, BUT I HAD NO TIME TO CHECK IT. I FAILED TO SEE THE ANGLE TO THE RWY WAS WRONG, HE HAD A STRAIGHT IN FINAL. I FAILED TO NOTE THE LOC DISPLAY MOVING SLOWLY FROM LEFT TO RIGHT AS WE FLEW THROUGH THE LOC. (APCH MODE OF FD WAS ARMED AND CAPTURED WITH AN APPROPRIATE LATERAL COMMAND.) WHEN I NOTICED THE FULL DEFLECTION RIGHT AND THE APCH COURSE ON THE MAP WAY TO THE LEFT, I COMMENTED THAT 'SOMETHING IS WRONG'. THE CTLR QUERIED US IF WE HAD THE LOC OK AND REITERATED THE FREQ WHICH WE BOTH IMMEDIATELY CHECKED. CTLR STATED HE 'HAD US LEFT OF COURSE AND TO TURN RIGHT TO A NEW INTERCEPT HDG OF 170?' THE CAPT HAD INDICATED TO ATC 'WE HAD A DISCREPANCY, AND TO KEEP US ADVISED OF OUR PROGRESS'. I COMMENTED THAT THE RAW DATA AGREED WITH THE CTLR BUT THE HDG WOULD NEVER TAKE US ON AN INTERCEPT WITH THE MAP COURSE. THE CTLR WAS VERY HELPFUL AND SAID WE 'WERE IN GOOD SHAPE AND APCHING THE LOC'. THE CAPT WAS LOST IN THE PROBLEM SO I REACHED DOWN AND PUT MY DISPLAY BACK ON FULL-UP COMPASS ROSE ILS MODE. I CONCURRED WITH THE CTLR AND CONCLUDED THE CAPT'S APCH HAD LED ME ASTRAY AND THAT I WAS STAYING ON RAW DATA. THIS LEG I WAS 100% RAW DATA AND WENT TO THE 'COMPUTER MAP' FOR A LOOK AT THE ABSOLUTE WRONG TIME. THE CAPT WAS CONFUSED AT THIS POINT AND I WAS NOW BACK ON THE APCH WITH RAW DATA, I COULD NOT GET HIM TO ABANDON THE COMPUTER. I CALLED OUT GLIDE SLOPE MOVING, INTERCEPT, AND GLIDE SLOPE HIGH AS I STATED I WOULD NOT DSND BELOW 3000' UNLESS HE WAS SURE OF WHERE WE WERE ALSO. HE CONCURRED. THE CAPT RECOGNIZING MY CALLS QUICKLY GOT ON RAW DATA AND COMMANDED ME TO DSND WHICH I DID AT ABOUT 1200 FPM. WE PROCEEDED AND I STATED THAT IF WE DID NOT BREAK OUT VISUALLY OR CAPTURE THE GLIDE SLOPE AT A COMFORTABLE ALT FOR MANEUVERING, I WOULD EXECUTE A GO AROUND. CAPT AGREED. WE BROKE OUT ABOUT 900' ON THE LOC AS WE CAUGHT THE GLIDE SLOPE AND WERE IN A COMFORTABLE POSITION FOR THE TURN TO FINAL WITH A SAFE UNEVENTFUL AND SMOOTH LNDG.

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.