Less than standard separation between a commuter light transport and air carrier B737. The departure controller climbed the B737 to the altitude of the light transport without coordination with the approach controller. The light transport received a TCASII RA to descend at the same time the controller issued an immediate descent clearance to 5000 ft. The light transport had traffic visually and had already started a descent. Operational error.

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Attributes
ACN	345809
Time
Date	199608
Day	Sun
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : dfw
State Reference	TX
Altitude	msl bound lower : 6000 msl bound upper : 6000
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Controlling Facilities	tracon : dfw
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
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
Aircraft 2
Operator	common carrier : air carrier
Make Model Name	B737 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	climbout : intermediate altitude cruise other
Route In Use	departure other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : cfi pilot : atp
Experience	flight time last 90 days : 240 flight time total : 6500 flight time type : 240
ASRS Report	345809
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : instrument pilot : atp
Experience	flight time last 90 days : 200 flight time total : 14020 flight time type : 1000
ASRS Report	345812
Events
Anomaly	non adherence : published procedure non adherence : required legal separation other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : unspecified other controllera other flight crewa
Resolutory Action	controller : issued new clearance flight crew : took evasive action other
Consequence	Other
Miss Distance	horizontal : 5000 vertical : 250
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error

Narrative:

A B737 off of dal was noted on our TCASII at our altitude and closing. TCASII gave a TA and then an RA to descend. At the same time, our approach controller told us to descend immediately to 5000 ft and that he did not know that the dal controller had been climbing his traffic. We saw the landing lights of the other traffic and had already initiated our descent before clearance from approach but had only descended about 100 ft before he began apologizing for his and the dal controller's apparent miscom. This type of situation happens too frequently and in my opinion is caused by an overworked ATC system.

Original NASA ASRS Text

Title: LTSS BTWN A COMMUTER LTT AND ACR B737. THE DEP CTLR CLBED THE B737 TO THE ALT OF THE LTT WITHOUT COORD WITH THE APCH CTLR. THE LTT RECEIVED A TCASII RA TO DSND AT THE SAME TIME THE CTLR ISSUED AN IMMEDIATE DSCNT CLRNC TO 5000 FT. THE LTT HAD TFC VISUALLY AND HAD ALREADY STARTED A DSCNT. OPERROR.

Narrative: A B737 OFF OF DAL WAS NOTED ON OUR TCASII AT OUR ALT AND CLOSING. TCASII GAVE A TA AND THEN AN RA TO DSND. AT THE SAME TIME, OUR APCH CTLR TOLD US TO DSND IMMEDIATELY TO 5000 FT AND THAT HE DID NOT KNOW THAT THE DAL CTLR HAD BEEN CLBING HIS TFC. WE SAW THE LNDG LIGHTS OF THE OTHER TFC AND HAD ALREADY INITIATED OUR DSCNT BEFORE CLRNC FROM APCH BUT HAD ONLY DSNDED ABOUT 100 FT BEFORE HE BEGAN APOLOGIZING FOR HIS AND THE DAL CTLR'S APPARENT MISCOM. THIS TYPE OF SIT HAPPENS TOO FREQUENTLY AND IN MY OPINION IS CAUSED BY AN OVERWORKED ATC SYS.

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.