Air carrier X had less than standard separation from air carrier Y. System error.

Attributes
ACN	210136
Time
Date	199205
Day	Sat
Local Time Of Day	1801 To 2400
Place
Locale Reference	atc facility : ewr
State Reference	NJ
Altitude	msl bound lower : 14000 msl bound upper : 14000
Environment
Flight Conditions	IMC
Light	Dusk
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Flight Phase	climbout : intermediate altitude
Route In Use	enroute : on vectors enroute airway : n90
Flight Plan	IFR
Aircraft 2
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Flight Phase	climbout : intermediate altitude
Route In Use	enroute : on vectors
Flight Plan	IFR
Person 1
Affiliation	government : faa
Function	controller : departure
Qualification	controller : radar
Experience	controller radar : 2
ASRS Report	210136
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	conflict : airborne less severe non adherence : published procedure
Independent Detector	other controllera
Resolutory Action	controller : issued new clearance other
Consequence	Other
Miss Distance	horizontal : 12000 vertical : 500
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error

Narrative:

I was working radar departure position. Position was moderately busy and complex. Many similar call signs added complexity. I received 2 air carrier aircraft medium large transport's from previous controller climbing nwbound to 10000 ft. Aircraft were intrail and I assumed air carrier Y was on same heading as air carrier X. I climbed air carrier X and turned it northbound. I climbed air carrier Y and planned to turn it northbound also to follow air carrier X. Dealt with other aircraft on frequency, scanned scope and saw air carrier X northbound and air carrier Y nwbound on converging courses and both climbing to 14000 ft. Separation was not ensured and action was taken to ensure separation. I realized I was not given aircraft on same headings. By turning air carrier X north, I put it in the path of air carrier Y. I had incorrectly assumed air carrier Y was on a heading to go behind air carrier X. Had I observed headings more carefully, or had I assigned initial heading to both aircraft instead of assuming incident would have been avoided.

Original NASA ASRS Text

Title: ACR X HAD LTSS FROM ACR Y. SYS ERROR.

Narrative: I WAS WORKING RADAR DEP POS. POS WAS MODERATELY BUSY AND COMPLEX. MANY SIMILAR CALL SIGNS ADDED COMPLEXITY. I RECEIVED 2 ACR ACFT MLG'S FROM PREVIOUS CTLR CLBING NWBOUND TO 10000 FT. ACFT WERE INTRAIL AND I ASSUMED ACR Y WAS ON SAME HDG AS ACR X. I CLBED ACR X AND TURNED IT NBOUND. I CLBED ACR Y AND PLANNED TO TURN IT NBOUND ALSO TO FOLLOW ACR X. DEALT WITH OTHER ACFT ON FREQ, SCANNED SCOPE AND SAW ACR X NBOUND AND ACR Y NWBOUND ON CONVERGING COURSES AND BOTH CLBING TO 14000 FT. SEPARATION WAS NOT ENSURED AND ACTION WAS TAKEN TO ENSURE SEPARATION. I REALIZED I WAS NOT GIVEN ACFT ON SAME HDGS. BY TURNING ACR X N, I PUT IT IN THE PATH OF ACR Y. I HAD INCORRECTLY ASSUMED ACR Y WAS ON A HDG TO GO BEHIND ACR X. HAD I OBSERVED HDGS MORE CAREFULLY, OR HAD I ASSIGNED INITIAL HDG TO BOTH ACFT INSTEAD OF ASSUMING INCIDENT WOULD HAVE BEEN AVOIDED.

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.