Loss of separation occurred while controller was in process of decombining departure positions.

Attributes
ACN	179961
Time
Date	199106
Day	Mon
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : lga
State Reference	NY
Altitude	msl bound lower : 15000 msl bound upper : 15500
Environment
Flight Conditions	VMC
Light	Dawn
Aircraft 1
Controlling Facilities	tracon : n90 tower : grr
Operator	common carrier : air carrier
Make Model Name	Large Transport, Low Wing, 3 Turbojet Eng
Flight Phase	climbout : initial
Route In Use	departure other
Flight Plan	IFR
Aircraft 2
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Flight Phase	climbout : initial
Route In Use	departure other
Flight Plan	IFR
Person 1
Affiliation	government : faa
Function	controller : departure
Qualification	controller : radar
Experience	controller radar : 2
ASRS Report	179961
Person 2
Affiliation	government : faa
Function	controller : departure
Qualification	controller : radar
Events
Anomaly	conflict : airborne less severe non adherence : published procedure non adherence : required legal separation other anomaly other
Independent Detector	other controllera
Resolutory Action	controller : issued new clearance
Consequence	Other
Miss Distance	horizontal : 0 vertical : 500
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error

Narrative:

I was told to open a radar position that was combined with another radar position. I set up my radar scope and informed the departure controllers that the position was open on my frequency. The controller working the position combined was training and they became busy at the same time that I opened the position. The other controller had one aircraft on his frequency, which he climbed from 10000 to 15000'. I had another aircraft climbing from 10000 to 15000' on my frequency. His medium large transport Y saw my large transport X. They were converging. My aircraft was at the same altitude. I climbed my aircraft to 16000' and turned to a 360 degree heading from 320 degrees. I called traffic. My large transport didn't see the medium large transport until he was right on top of him. Confusion between myself and the busy other controller contributed to the incident. In my 2 1/2 yrs of experience, I have seen many (25 or more) times when opening combined positions or position relief briefings cause much confusion between the various parties. If both aircraft had been on same frequency, this would not have happened.

Original NASA ASRS Text

Title: LOSS OF SEPARATION OCCURRED WHILE CTLR WAS IN PROCESS OF DECOMBINING DEP POSITIONS.

Narrative: I WAS TOLD TO OPEN A RADAR POS THAT WAS COMBINED WITH ANOTHER RADAR POS. I SET UP MY RADAR SCOPE AND INFORMED THE DEP CTLRS THAT THE POS WAS OPEN ON MY FREQ. THE CTLR WORKING THE POS COMBINED WAS TRNING AND THEY BECAME BUSY AT THE SAME TIME THAT I OPENED THE POS. THE OTHER CTLR HAD ONE ACFT ON HIS FREQ, WHICH HE CLBED FROM 10000 TO 15000'. I HAD ANOTHER ACFT CLBING FROM 10000 TO 15000' ON MY FREQ. HIS MLG Y SAW MY LGT X. THEY WERE CONVERGING. MY ACFT WAS AT THE SAME ALT. I CLBED MY ACFT TO 16000' AND TURNED TO A 360 DEG HDG FROM 320 DEGS. I CALLED TFC. MY LGT DIDN'T SEE THE MLG UNTIL HE WAS RIGHT ON TOP OF HIM. CONFUSION BTWN MYSELF AND THE BUSY OTHER CTLR CONTRIBUTED TO THE INCIDENT. IN MY 2 1/2 YRS OF EXPERIENCE, I HAVE SEEN MANY (25 OR MORE) TIMES WHEN OPENING COMBINED POSITIONS OR POS RELIEF BRIEFINGS CAUSE MUCH CONFUSION BTWN THE VARIOUS PARTIES. IF BOTH ACFT HAD BEEN ON SAME FREQ, THIS WOULD NOT HAVE HAPPENED.

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.