Air carrier MD88 flight crew execute evasive maneuver to avoid traffic on the same routing into dfw.

Attributes
ACN	410276
Time
Date	199808
Day	Tue
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : byp airport : dfw
State Reference	TX
Altitude	msl bound lower : 6000 msl bound upper : 7000
Environment
Flight Conditions	Marginal
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : dfw
Operator	common carrier : air carrier
Make Model Name	MD-88
Operating Under FAR Part	Part 121
Navigation In Use	Other Other
Flight Phase	descent other
Route In Use	arrival other arrival star : star enroute : on vectors
Flight Plan	IFR
Aircraft 2
Operator	common carrier : air carrier
Make Model Name	Saab-Scania Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Navigation In Use	Other Other
Flight Phase	cruise other
Route In Use	arrival other arrival star : star
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Experience	flight time last 90 days : 150 flight time total : 2500 flight time type : 225
ASRS Report	410276
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 200 flight time total : 8000 flight time type : 3000
ASRS Report	411138
Events
Anomaly	conflict : nmac non adherence : required legal separation non adherence : published procedure other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : unspecified other flight crewa
Resolutory Action	flight crew : took evasive action
Consequence	Other
Miss Distance	horizontal : 200 vertical : 250
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error

Narrative:

On the bonham arrival near the lemyn intersection, we were instructed to descend from 7000 ft to 6000 ft. We were at 230 KIAS as assigned. Approximately 1-2 mi prior to lemyn we got a TCASII TA. The captain and myself looked outside for the target. We did not get a visual prior to the RA which quickly followed. The captain disconnected the autoplt, started a climb and a right turn to 260 degrees. Our instructions were to turn to 260 degrees at lemyn intersection. As we started the climb and turn, I saw the target (a saab 340) below us, going in the same direction. I estimated the near miss at 300 ft vertically and 300 ft horizontally. The TCASII audio climb warning occurred during this time. The captain picked up the saab out of the left window. His estimate on the closest point of approach is 200 ft laterally and between 200-300 ft vertically. The vertical estimate is based on the TCASII RA data tag. We believe the saab either did not leave his assigned altitude or did so with an inappropriate rate of descent. We were not on the same approach control frequency which might have caused some lack of mutual awareness. Controller distraction or inattn may have contributed to the situation.

Original NASA ASRS Text

Title: ACR MD88 FLC EXECUTE EVASIVE MANEUVER TO AVOID TFC ON THE SAME ROUTING INTO DFW.

Narrative: ON THE BONHAM ARR NEAR THE LEMYN INTXN, WE WERE INSTRUCTED TO DSND FROM 7000 FT TO 6000 FT. WE WERE AT 230 KIAS AS ASSIGNED. APPROX 1-2 MI PRIOR TO LEMYN WE GOT A TCASII TA. THE CAPT AND MYSELF LOOKED OUTSIDE FOR THE TARGET. WE DID NOT GET A VISUAL PRIOR TO THE RA WHICH QUICKLY FOLLOWED. THE CAPT DISCONNECTED THE AUTOPLT, STARTED A CLB AND A R TURN TO 260 DEGS. OUR INSTRUCTIONS WERE TO TURN TO 260 DEGS AT LEMYN INTXN. AS WE STARTED THE CLB AND TURN, I SAW THE TARGET (A SAAB 340) BELOW US, GOING IN THE SAME DIRECTION. I ESTIMATED THE NEAR MISS AT 300 FT VERTLY AND 300 FT HORIZLY. THE TCASII AUDIO CLB WARNING OCCURRED DURING THIS TIME. THE CAPT PICKED UP THE SAAB OUT OF THE L WINDOW. HIS ESTIMATE ON THE CLOSEST POINT OF APCH IS 200 FT LATERALLY AND BTWN 200-300 FT VERTLY. THE VERT ESTIMATE IS BASED ON THE TCASII RA DATA TAG. WE BELIEVE THE SAAB EITHER DID NOT LEAVE HIS ASSIGNED ALT OR DID SO WITH AN INAPPROPRIATE RATE OF DSCNT. WE WERE NOT ON THE SAME APCH CTL FREQ WHICH MIGHT HAVE CAUSED SOME LACK OF MUTUAL AWARENESS. CTLR DISTR OR INATTN MAY HAVE CONTRIBUTED TO THE SIT.

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.