MD11 DEPARTING DFW FAILS TO FOLLOW TRANSITION PORTION OF NOBLY SID.

Narrative

THE CAPT WAS THE PLT FLYING AND LOADED THE FLT PLAN FOR THE FILED RTE: DALLAS 8 DEP LIT BYH AND RWY 36R. DISTANCES WERE CHKED AND WERE REASONABLE. THE FO CALLED FOR CLRNC; RECEIVED THE NOBLY 2 RNAV TO LIT RWY 36R AND MADE THE CHANGES IN THE FMS. NO FLT PLAN DISCREPANCIES WERE NOTED BY EITHER PLT. DURING TAXI OUT; THE RWY WAS CHANGED TO 35L. THE FO CORRECTLY ENTERED THE CHANGE IN THE FMS. PRIOR TO SWITCHING TO TWR; WE WERE ASKED TO VERIFY BOTH THE SID AND THE FIRST WAYPOINT; CUZEN. AS BRIEFED; THE SID WAS FLOWN IN NAV. PROFILE WAS ENGAGED AROUND 500 FT AGL. SOON AFTER TKOF; WHILE ON DEP FREQ; WE WERE CLRED TO RESUME NORMAL SPD AND GIVEN A VECTOR OF SOMETHING CLOSE TO 030 DEGS OR 040 DEGS. THE CLB TO ALT WAS FAST DUE TO THE LIGHT WT OF THE ACFT. AUTOFLT WAS ENGAGED PASSING 18000 FT. FROM OUR ASSIGNED HDG; WE WERE CLRED DIRECT TO NOBLY. THE PNF EXECUTED THIS TASK IN THE FMS AND IT WAS VERIFIED BY THE PF. THE ACFT WAS IN LEVEL FLT EITHER AT OR SHORTLY AFTER NOBLY; AUTOFLT 1 AND NAV 1 ENGAGED. SHORTLY AFTER PASSING NOBLY; ESTABLISHED ON THE OUTBOUND TRACK; THE PNF NOTICED A DISCREPANCY BETWEEN THE FLT PLAN AND THE FMS. THE FMS WAS SHOWING A DIRECT COURSE BETWEEN NOBLY AND LIT. THE FLT PLAN AND SID HAD THE POINTS COBUG AND ORTRO. PRIOR TO REACHING COBUG; THE PNF ATTEMPTED TO CORRECT THIS IN THE FMS. INITIALLY A FLT DISCONTINUITY OCCURRED CAUSING THE NAV SYSTEM TO SWITCH INTO HDG MODE. HOWEVER; DIRECT TO LIT WAS RE-ESTABLISHED AND NAV RE-ENGAGED. THE POINTS COBUG AND ORTRO WERE ENTERED INTO THE FIX PAGE FOR REFERENCE; NOT NAVIGATION. SHORTLY BEFORE COBUG; FT WORTH CTR ASKED US ABOUT OUR CLRNC AND RTE. THE PNF REPLIED CORRECTLY WE WERE PROCEEDING TO LIT AND THAT WE HAD BEEN CLRED VIA THE NOBLY 2. AT THIS POINT WE HAD NOT YET REACHED COBUG. OUR FIX PAGE SHOWED THAT WE WOULD PASS ABEAM COBUG BY 4 MILES AND THAT WE WOULD PASS ABEAM ORTRO 12 MILES. WE WERE ADVISED OF THE DEV AND GIVEN A PHONE NUMBER TO CALL AFTER LNDG. HOWEVER; WE WERE NOT ADVISED TO NAVIGATE TO EITHER POINT OR CORRECT OUR TRACK OR RESUME THE SID. A COMMAND TO DO ANY OF THOSE THINGS WOULD HAVE REDUCED THE LATERAL ERROR TO ALMOST ZERO AT COBUG (WE WERE CLOSING FAST WITH THE 130 KT TAILWIND) AND CERTAINLY ZERO AT ORTRO. UPON ARR AT BYH; I PHONED FT WORTH CTR NUMBER GIVEN AND SPOKE WITH THE SUPVR. DURING OUR CONVERSATION; I WAS INFORMED THERE WERE SEVERAL SUCH EVENTS TAKING PLACE ON THE NOBLY SID WHERE RTE POINTS WERE DROPPING OUT ESPECIALLY AFTER RWY CHANGES. AFTER THE RWY CHANGE; THE INITIAL PAGE (PAGE 1) POINTS WERE VERIFIED IN THE FMS HOWEVER; POINTS BEYOND THE FIRST PAGE WERE NOT RECHKED SINCE THERE WERE NO INDICATIONS THAT ANYTHING HAD CHANGED. FOR FUTURE EVENTS OF THIS NATURE; IT SEEMS NECESSARY TO AGAIN CHK ALL WAYPOINTS ASSOCIATED WITH ANY DEP.