TRACON controller described a loss of separation event when failing to restrict a departure below an...

Narrative:

Aircraft X; a C421; was an overflight cleared direct ZZZ at 13;000 ft. Air carrier Y was an A319 on a RNAV departure; basically a head on situation. I believed that I had climbed air carrier Y to 12;000 ft as I had done with the previous departures. I did not; the strip clearly indicated 14;000 ft. Traffic was issued to air carrier Y. The pilot stated he was climbing through 12;000 for 14;000 ft as assigned. The strip verified the clearance. Separation was lost before the C421 called the traffic in sight. I am not sure what would have prevented it. The only distraction was when I asked flight data to make an amendment on the flight plan of the C421.

Original NASA ASRS Text

Title: TRACON Controller described a loss of separation event when failing to restrict a departure below an over flight; noting all previous departures were restricted and he assumed he had issued the same restrictive altitudes.

Narrative: Aircraft X; a C421; was an overflight cleared direct ZZZ at 13;000 FT. Air Carrier Y was an A319 on a RNAV Departure; basically a head on situation. I believed that I had climbed Air Carrier Y to 12;000 FT as I had done with the previous departures. I did not; the strip clearly indicated 14;000 FT. Traffic was issued to Air Carrier Y. The pilot stated he was climbing through 12;000 for 14;000 FT as assigned. The strip verified the clearance. Separation was lost before the C421 called the traffic in sight. I am not sure what would have prevented it. The only distraction was when I asked Flight Data to make an amendment on the flight plan of the C421.

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.

Attributes
ACN	958248
Time
Date	201107
Local Time Of Day	1801-2400
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Light	Dusk
Aircraft 1
Make Model Name	Golden Eagle 421
Flight Phase	Cruise
Flight Plan	IFR
Aircraft 2
Make Model Name	A319
Operating Under FAR Part	Part 121
Flight Phase	Climb
Flight Plan	IFR
Person 1
Function	Approach Departure
Qualification	Air Traffic Control Fully Certified
Events
Anomaly	ATC Issue All Types Deviation - Procedural Published Material / Policy

TRACON controller described a loss of separation event when failing to restrict a departure below an over flight; noting all previous departures were restricted and he assumed he had issued the same restrictive altitudes.