Pct controller described a loss of separation event during visual approach procedures to the runway ...

Narrative:

I was working all three finals at dulles combined; having just relieved another controller. During the briefing the controller advised me that a SF34; approaching the airport from the west; had been 'cleared for the visual'. I incorrectly assumed he meant cleared for the visual to 01C; when in fact he had been cleared for the visual to 01R. Had I checked the scratch pad I would've realized this; or had I picked up on something he added at the end of the briefing; that 01C was now open but had been closed and so I could expect several aircraft to be tagged for 01R no matter where they were approaching from. Unfortunately; I didn't realize the problem and turned the SF34 in for 01R; believing the A330 was heading to 01C. After I had cleared the SF34 for the visual reference the airport I realized the issue and called traffic to the SF34 in an attempt to gain visual separation. He eventually sighted the A330; but at this point separation had diminished to below 2.5 miles lateral; I'm not sure what the vertical separation was. Additionally; the SF34 was significantly faster than the A330 and advised that he was slowing to his approach speed. I acknowledge his transmission and switched him to the tower; but lateral separation continued to diminish; eventually forcing a go-around. This error was the result of inattention to briefing items on my part and an incomplete briefing from the relieved controller. However; the responsibility must lie with me to verify the landing runway assignment of all aircraft when assuming control of the position. Relieved controllers should advise specifically of any unusual situations; such as an aircraft cleared for; an other than; expected runway. Relieving controllers must verify all scratch pad data and ask for any clarification if there is doubt about a particular aircraft's plan.

Original NASA ASRS Text

Title: PCT Controller described a loss of separation event during visual approach procedures to the Runway 01 complex; noting the failure of a proper relief briefing and data block observance as causal factors.

Narrative: I was working all three finals at Dulles combined; having just relieved another Controller. During the briefing the Controller advised me that a SF34; approaching the airport from the west; had been 'cleared for the visual'. I incorrectly assumed he meant cleared for the visual to 01C; when in fact he had been cleared for the visual to 01R. Had I checked the scratch pad I would've realized this; or had I picked up on something he added at the end of the briefing; that 01C was now open but had been closed and so I could expect several aircraft to be tagged for 01R no matter where they were approaching from. Unfortunately; I didn't realize the problem and turned the SF34 in for 01R; believing the A330 was heading to 01C. After I had cleared the SF34 for the visual reference the airport I realized the issue and called traffic to the SF34 in an attempt to gain visual separation. He eventually sighted the A330; but at this point separation had diminished to below 2.5 miles lateral; I'm not sure what the vertical separation was. Additionally; the SF34 was significantly faster than the A330 and advised that he was slowing to his approach speed. I acknowledge his transmission and switched him to the Tower; but lateral separation continued to diminish; eventually forcing a go-around. This error was the result of inattention to briefing items on my part and an incomplete briefing from the Relieved Controller. However; the responsibility must lie with me to verify the landing runway assignment of all aircraft when assuming control of the position. Relieved Controllers should advise specifically of any unusual situations; such as an aircraft cleared for; an other than; expected runway. Relieving Controllers must verify all scratch pad data and ask for any clarification if there is doubt about a particular aircraft's plan.

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	927728
Time
Date	201101
Local Time Of Day	1801-2400
Place
Locale Reference	IAD.Airport
State Reference	DC
Aircraft 1
Make Model Name	A330
Operating Under FAR Part	Part 121
Flight Phase	Landing
Route In Use	Visual Approach
Flight Plan	IFR
Aircraft 2
Make Model Name	Saab 340 Undifferentiated
Operating Under FAR Part	Part 121
Flight Phase	Landing
Route In Use	Visual Approach
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 during visual approach procedures to the runway 01 complex; noting the failure of a proper relief briefing and data block observance as causal factors.