Narrative:

Aircraft X had previously conducted parachute jump operations. Aircraft Y was a VFR overflight southbound passing east of the airport. Aircraft Y had been handed off to approach and a communication change completed. I observed a beacon code east of the airport climbing toward aircraft Y. I suspected the beacon code was aircraft X. I quickly confirmed beacon code assignment with the edst (en route decision support tool). Even though aircraft X hadn't called on frequency; I issued a traffic alert to aircraft X to turn left immediately just hoping the aircraft was monitoring my frequency. Aircraft X was on frequency and turned left immediately. I gave additional information on the traffic type and location. Aircraft X saw traffic and barely avoided it. Radar targets nearly merged at the same altitude. Aircraft X then stated that traffic information just appeared on 'the box.' normal operations then resumed. [I suggest the jump operator] call via land line 10 minutes prior to initiating jump operations to allow for tactical adjustment of non-participating aircraft. [ATC could] sterilize the airspace in a 10 mile radius around the airport from initial call for jump operations until last jump completed. ATC should conduct quarterly telephone conferences and yearly face-to-face meetings with jump operators to ensure that existing procedures are being adhered to and to make any necessary adjustments.

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Original NASA ASRS Text

Title: A Center Controller reported an NMAC between parachute jump aircraft and a VFR aircraft.

Narrative: Aircraft X had previously conducted parachute jump operations. Aircraft Y was a VFR overflight southbound passing east of the airport. Aircraft Y had been handed off to Approach and a communication change completed. I observed a beacon code east of the airport climbing toward Aircraft Y. I suspected the beacon code was Aircraft X. I quickly confirmed beacon code assignment with the EDST (En route Decision Support Tool). Even though Aircraft X hadn't called on frequency; I issued a traffic alert to Aircraft X to turn left immediately just hoping the aircraft was monitoring my frequency. Aircraft X was on frequency and turned left immediately. I gave additional information on the traffic type and location. Aircraft X saw traffic and barely avoided it. Radar targets nearly merged at the same altitude. Aircraft X then stated that traffic information just appeared on 'the box.' Normal operations then resumed. [I suggest the jump operator] call via land line 10 minutes prior to initiating jump operations to allow for tactical adjustment of non-participating aircraft. [ATC could] sterilize the airspace in a 10 mile radius around the airport from initial call for jump operations until last jump completed. ATC should conduct quarterly telephone conferences and yearly face-to-face meetings with jump operators to ensure that existing procedures are being adhered to and to make any necessary adjustments.

Data retrieved from NASA's ASRS site 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.