B737-800 flight crew encounters nobly RNAV SID transition anomaly.

Attributes
ACN	700699
Time
Date	200606
Local Time Of Day	0601 To 1200
Place
Locale Reference	intersection : nobly
State Reference	TX
Altitude	msl single value : 37000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zfw.artcc
Operator	common carrier : air carrier
Make Model Name	B737-800
Operating Under FAR Part	Part 121
Flight Phase	cruise : level
Route In Use	departure sid : nobly
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
ASRS Report	700699
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
ASRS Report	700698
Events
Anomaly	aircraft equipment problem : critical non adherence : clearance non adherence : published procedure other spatial deviation
Independent Detector	other controllera
Resolutory Action	controller : issued advisory flight crew : returned to intended or assigned course
Supplementary
Problem Areas	Chart Or Publication Flight Crew Human Performance Aircraft
Primary Problem	Ambiguous
Air Traffic Incident	Pilot Deviation

Narrative:

Departed dfw on NOBLY2 departure. After passing nobly waypoint; aircraft proceeded directly to lit instead of waypoint cobug. ATC advised slightly left of course and we corrected back on course. Waypoints were checked prior to departure and transition was selected. During cruise; cobug did not appear on legs page. We reselected the departure and waypoints appeared normal. We proceeded on course.

Original NASA ASRS Text

Title: B737-800 FLT CREW ENCOUNTERS NOBLY RNAV SID TRANSITION ANOMALY.

Narrative: DEPARTED DFW ON NOBLY2 DEP. AFTER PASSING NOBLY WAYPOINT; ACFT PROCEEDED DIRECTLY TO LIT INSTEAD OF WAYPOINT COBUG. ATC ADVISED SLIGHTLY LEFT OF COURSE AND WE CORRECTED BACK ON COURSE. WAYPOINTS WERE CHKED PRIOR TO DEP AND TRANSITION WAS SELECTED. DURING CRUISE; COBUG DID NOT APPEAR ON LEGS PAGE. WE RESELECTED THE DEP AND WAYPOINTS APPEARED NORMAL. WE PROCEEDED ON COURSE.

Data retrieved from NASA's ASRS site as of January 2009 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.