Pct controller described a loss of separation event involving a dropped radar datablock; noting rada...

Narrative:

I took radar on a aircraft X en-route to jyo. The track disappeared 5 miles before crossing my boundary. The track did not re-acquire. Aircraft Y departed and was on a vector westbound. Approximately 5 miles south of csn VOR that is where the separation was lost. I called traffic to aircraft Y; thinking that the untracked target was a VFR aircraft maneuvering; and as the targets got closer; I gave aircraft Y a 'traffic alert' and turned him northbound. Then I asked someone to find out who this 5000 ft aircraft; traveling northeast bound; was. It was aircraft X on his way to jyo. This is not the first time in this radar coverage area that targets[tracks] get dropped off. It happens in both the choea sector and the barin sector. I don't even know if it went into my coast list. I will be more aware of this problem in the future and pay closer attention to small aircraft in this area. I will suggest to have the sectors de-combined when I feel it is getting to busy to handle.

Original NASA ASRS Text

Title: PCT Controller described a loss of separation event involving a dropped RADAR datablock; noting RADAR coverage in this subject area has resulted in previous dropped track events.

Narrative: I took RADAR on a Aircraft X en-route to JYO. The track disappeared 5 miles before crossing my boundary. The track did not re-acquire. Aircraft Y departed and was on a vector westbound. Approximately 5 miles south of CSN VOR that is where the separation was lost. I called traffic to Aircraft Y; thinking that the untracked target was a VFR aircraft maneuvering; and as the targets got closer; I gave Aircraft Y a 'Traffic Alert' and turned him northbound. Then I asked someone to find out who this 5000 FT aircraft; traveling northeast bound; was. It was Aircraft X on his way to JYO. This is not the first time in this RADAR coverage area that targets[tracks] get dropped off. It happens in both the Choea Sector and the Barin Sector. I don't even know if it went into my coast list. I will be more aware of this problem in the future and pay closer attention to small aircraft in this area. I will suggest to have the sectors de-combined when I feel it is getting to busy to handle.

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	943384
Time
Date	201104
Local Time Of Day	1201-1800
Place
Locale Reference	PCT.TRACON
State Reference	VA
Aircraft 1
Make Model Name	Diamond Aircraft Undifferentiated or Other Model
Flight Phase	Cruise
Flight Plan	IFR
Aircraft 2
Make Model Name	Experimental
Flight Phase	Initial Climb
Route In Use	Vectors
Flight Plan	IFR
Person 1
Function	Approach
Qualification	Air Traffic Control Fully Certified
Events
Anomaly	ATC Issue All Types Deviation - Procedural Published Material / Policy

Pct controller described a loss of separation event involving a dropped radar datablock; noting radar coverage in this subject area has resulted in previous dropped track events.