Narrative:

On air carrier flight XXX, dec/xa/95, we programmed our FMC with the densan route, which was in the database. We selected the rocki 2 departure and the dvc transition, the runway, and activated the route after checking that everything was in. After takeoff and climbing out southwest in VFR conditions, we experienced a delay in receiving an altitude clearance above 10000 ft. After that we were cleared on a heading to intercept the dvc transition. We activated an intercept to the first waypoint on the legs page. A short time later ZDV called and said that we were south of the dvc transition. We checked and found that the waypoint that we used to activate the leg was the dvc VOR and not baylr intersection. The route page indicated that rocki 2 with dvc transition was part of the active route. However, the intermediate waypoints were not on the active legs page when we went to activate the transition to fly on LNAV. I should have checked closer when I called for the intercept to the first waypoint. We were south of course but I do not feel that any traffic conflict occurred. Supplemental information from acn 323462: navigation error occurred during climb out from den. Clearance was den rockies 2 dove creek transition. We took off runway 25, climbed to 10000 ft heading 240 degrees. Departure was working arrs over us and did not clear us to climb until we asked for higher altitude 20 plus mi southwest of den. Switched to center frequency clear to fly heading 230 degrees intercept rockies 2 dvc transition. I went to CDU and extended dvc which was the first fix showing. Somehow the FMC had dropped baylr and bobba intxns. Route into dvc was not the departure transition but some distance south. A 230 degree heading was parallel track to the route showing but south of the correct course. I became suspicious that the route was not correct. When the assigned 230 degree heading would not intercept before dvc VOR. I switched to manual VOR (raw data) and saw we were south of course at which time ATC called and asked if we were on course. I estimate we were 3-5 mi south of desired course. I believe this happened as a result of not double-checking the legs page of the FMC and being distracted by the lack of a climb clearance above 10000 ft southwest of den. I have started to trust the FMC too much and have stopped backing it up with raw data.

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Original NASA ASRS Text

Title: FMC DROPPED INITIAL INTXNS BTWN DEN AND DVC PROMPTING CREW TO PROCEED DIRECT TO DVC RATHER THAN THE PRELIMINARY ROUTING PRIOR TO DVC.

Narrative: ON ACR FLT XXX, DEC/XA/95, WE PROGRAMMED OUR FMC WITH THE DENSAN RTE, WHICH WAS IN THE DATABASE. WE SELECTED THE ROCKI 2 DEP AND THE DVC TRANSITION, THE RWY, AND ACTIVATED THE RTE AFTER CHKING THAT EVERYTHING WAS IN. AFTER TKOF AND CLBING OUT SW IN VFR CONDITIONS, WE EXPERIENCED A DELAY IN RECEIVING AN ALT CLRNC ABOVE 10000 FT. AFTER THAT WE WERE CLRED ON A HEADING TO INTERCEPT THE DVC TRANSITION. WE ACTIVATED AN INTERCEPT TO THE FIRST WAYPOINT ON THE LEGS PAGE. A SHORT TIME LATER ZDV CALLED AND SAID THAT WE WERE S OF THE DVC TRANSITION. WE CHKED AND FOUND THAT THE WAYPOINT THAT WE USED TO ACTIVATE THE LEG WAS THE DVC VOR AND NOT BAYLR INTXN. THE RTE PAGE INDICATED THAT ROCKI 2 WITH DVC TRANSITION WAS PART OF THE ACTIVE RTE. HOWEVER, THE INTERMEDIATE WAYPOINTS WERE NOT ON THE ACTIVE LEGS PAGE WHEN WE WENT TO ACTIVATE THE TRANSITION TO FLY ON LNAV. I SHOULD HAVE CHKED CLOSER WHEN I CALLED FOR THE INTERCEPT TO THE FIRST WAYPOINT. WE WERE S OF COURSE BUT I DO NOT FEEL THAT ANY TFC CONFLICT OCCURRED. SUPPLEMENTAL INFO FROM ACN 323462: NAV ERROR OCCURRED DURING CLBOUT FROM DEN. CLRNC WAS DEN ROCKIES 2 DOVE CREEK TRANSITION. WE TOOK OFF RWY 25, CLBED TO 10000 FT HEADING 240 DEGS. DEP WAS WORKING ARRS OVER US AND DID NOT CLR US TO CLB UNTIL WE ASKED FOR HIGHER ALT 20 PLUS MI SW OF DEN. SWITCHED TO CTR FREQ CLR TO FLY HEADING 230 DEGS INTERCEPT ROCKIES 2 DVC TRANSITION. I WENT TO CDU AND EXTENDED DVC WHICH WAS THE FIRST FIX SHOWING. SOMEHOW THE FMC HAD DROPPED BAYLR AND BOBBA INTXNS. RTE INTO DVC WAS NOT THE DEP TRANSITION BUT SOME DISTANCE S. A 230 DEG HDG WAS PARALLEL TRACK TO THE RTE SHOWING BUT S OF THE CORRECT COURSE. I BECAME SUSPICIOUS THAT THE RTE WAS NOT CORRECT. WHEN THE ASSIGNED 230 DEG HDG WOULD NOT INTERCEPT BEFORE DVC VOR. I SWITCHED TO MANUAL VOR (RAW DATA) AND SAW WE WERE S OF COURSE AT WHICH TIME ATC CALLED AND ASKED IF WE WERE ON COURSE. I ESTIMATE WE WERE 3-5 MI S OF DESIRED COURSE. I BELIEVE THIS HAPPENED AS A RESULT OF NOT DOUBLE-CHKING THE LEGS PAGE OF THE FMC AND BEING DISTRACTED BY THE LACK OF A CLB CLRNC ABOVE 10000 FT SW OF DEN. I HAVE STARTED TO TRUST THE FMC TOO MUCH AND HAVE STOPPED BACKING IT UP WITH RAW DATA.

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.