MD80 has malfunctioning FMS during bleco RNAV SID from dfw.

Attributes
ACN	696053
Time
Date	200605
Local Time Of Day	1801 To 2400
Place
Locale Reference	intersection : corts
State Reference	TX
Altitude	msl single value : 10000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : d10.tracon
Operator	common carrier : air carrier
Make Model Name	MD-80 Series (DC-9-80) Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Navigation In Use	other
Flight Phase	climbout : intermediate altitude
Route In Use	departure sid : bleco
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
ASRS Report	696053
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Events
Anomaly	aircraft equipment problem : critical other spatial deviation
Independent Detector	other flight crewa
Resolutory Action	aircraft : equipment problem dissipated controller : provided flight assist controller : issued new clearance flight crew : overrode automation
Supplementary
Problem Areas	Aircraft
Primary Problem	Aircraft

Narrative:

We were flying the BLECO2 departure. Somewhere between jgirl and corts intxns; the magenta course line disappeared and was replaced by two curved and crossed magenta course lines with the intersection of the lines about 4 miles in front of the aircraft. The aircraft simultaneously started a left turn to an unknown location. The first officer disconnected the autoplt while I was telling ATC that our FMS had failed. ATC gave us a heading and altitude and eventually asked if we could fly direct to bleco. A short time later; we found that we could fly to bleco and accepted the clearance from ATC. FMS operation was normal for the remainder of the flight.

Original NASA ASRS Text

Title: MD80 HAS MALFUNCTIONING FMS DURING BLECO RNAV SID FROM DFW.

Narrative: WE WERE FLYING THE BLECO2 DEP. SOMEWHERE BETWEEN JGIRL AND CORTS INTXNS; THE MAGENTA COURSE LINE DISAPPEARED AND WAS REPLACED BY TWO CURVED AND CROSSED MAGENTA COURSE LINES WITH THE INTXN OF THE LINES ABOUT 4 MILES IN FRONT OF THE ACFT. THE ACFT SIMULTANEOUSLY STARTED A L TURN TO AN UNKNOWN LOCATION. THE FO DISCONNECTED THE AUTOPLT WHILE I WAS TELLING ATC THAT OUR FMS HAD FAILED. ATC GAVE US A HDG AND ALT AND EVENTUALLY ASKED IF WE COULD FLY DIRECT TO BLECO. A SHORT TIME LATER; WE FOUND THAT WE COULD FLY TO BLECO AND ACCEPTED THE CLRNC FROM ATC. FMS OPERATION WAS NORMAL FOR THE REMAINDER OF THE FLT.

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.