D10 controller providing oft described conflict event when converging headings were not recognized s...

Attributes
ACN	877071
Time
Date	201002
Local Time Of Day	1801-2400
Place
Locale Reference	D10.TRACON
State Reference	TX
Aircraft 1
Make Model Name	Small Aircraft Low Wing 1 Eng Fixed Gear
Flight Phase	Descent
Route In Use	Vectors
Flight Plan	IFR
Aircraft 2
Make Model Name	Small Aircraft Low Wing 1 Eng Fixed Gear
Flight Phase	Descent
Route In Use	Vectors
Flight Plan	IFR
Person 1
Function	Approach
Qualification	Air Traffic Control Fully Certified
Events
Anomaly	ATC Issue All Types Conflict Airborne Conflict Deviation - Procedural Published Material / Policy

Narrative:

My trainee and I had just split AR8; (the addison final). We took the hand off from feeder east on aircraft X at 6000 and aircraft Y at 5000 both going to ads. They appeared to be on diverging headings and 3 miles apart when we took the hand offs. Aircraft X was out front and slightly slower. Right after aircraft X checked in he asked for lower. My trainee issued a decent thinking the aircraft were diverging. As we looked at it closer; we observed they were not diverging and getting closer; so my trainee issued a turn to insure diverging. As it turns out aircraft X was a 230 heading but on 245; and aircraft Y on a 245 heading was on 230. It set us up for the perfect error. Make sure you'r talking to both aircraft and verify their headings before using diverging separation.

Original NASA ASRS Text

Title: D10 controller providing OFT described conflict event when converging headings were not recognized soon enough to secure separation with corrective action/s.

Narrative: My trainee and I had just split AR8; (the Addison final). We took the hand off from Feeder East on Aircraft X at 6000 and Aircraft Y at 5000 both going to ADS. They appeared to be on diverging headings and 3 miles apart when we took the hand offs. Aircraft X was out front and slightly slower. Right after Aircraft X checked in he asked for lower. My trainee issued a decent thinking the aircraft were diverging. As we looked at it closer; we observed they were not diverging and getting closer; so my trainee issued a turn to insure diverging. As it turns out Aircraft X was a 230 heading but on 245; and Aircraft Y on a 245 heading was on 230. It set us up for the perfect error. Make sure you'r talking to both aircraft and verify their headings before using diverging separation.

Data retrieved from NASA's ASRS site as of April 2012 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.

D10 controller providing oft described conflict event when converging headings were not recognized soon enough to secure separation with corrective action/s.