TRACON controller described a loss of separation event involving a gca approach and a visual approac...

Attributes
ACN	995502
Time
Date	201202
Local Time Of Day	1201-1800
Place
Locale Reference	ZZZ.Airport
State Reference	US
Aircraft 1
Make Model Name	Regional Jet 200 ER/LR (CRJ200)
Operating Under FAR Part	Part 121
Flight Phase	Final Approach
Route In Use	Visual Approach
Flight Plan	IFR
Aircraft 2
Make Model Name	Super King Air 200
Operating Under FAR Part	Part 91
Flight Phase	Final Approach
Route In Use	Visual Approach
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

Narrative:

[There was] a BE20 on visual approach to the military base; talking to gca [and] a CRJ2 on visual approach to ZZZ talking to local control. The CRJ2 appeared to turn base at about 3 miles out; so I was no longer concerned with his separation from the BE20; but then the conflict alert (ca) went off; the CRJ2 had extended. I called local control; and he said that the CRJ2 was on base leg. I called gca and told them that the CRJ2 was on base leg. I measured the distance between the 2 aircraft and got 2.68 miles. There were 4 over-flights over ZZZ; so data-tag clutter was an issue; but I should have ensured that the CRJ2 was restricted to a shorter downwind. Recommendation; pay better attention; I should have ensured that the CRJ2 was restricted to a 5-mile final before I switched him.

Original NASA ASRS Text

Title: TRACON Controller described a loss of separation event involving a GCA Approach and a Visual Approach; the separation problem resulting from an extended downwind by the Visual Approach aircraft.

Narrative: [There was] a BE20 on Visual Approach to the military base; talking to GCA [and] a CRJ2 on Visual Approach to ZZZ talking to Local Control. The CRJ2 appeared to turn base at about 3 miles out; so I was no longer concerned with his separation from the BE20; but then the Conflict Alert (CA) went off; the CRJ2 had extended. I called Local Control; and he said that the CRJ2 was on base leg. I called GCA and told them that the CRJ2 was on base leg. I measured the distance between the 2 aircraft and got 2.68 miles. There were 4 over-flights over ZZZ; so data-tag clutter was an issue; but I should have ensured that the CRJ2 was restricted to a shorter downwind. Recommendation; pay better attention; I should have ensured that the CRJ2 was restricted to a 5-mile final before I switched him.

Data retrieved from NASA's ASRS site as of July 2013 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.

TRACON controller described a loss of separation event involving a gca approach and a visual approach; the separation problem resulting from an extended downwind by the visual approach aircraft.