TRACON controller described a loss of separation event when an aircraft minimally space with other a...

Narrative:

An E145 was being vector for a simultaneous xxr approach. He was descending to 4;000 because xxr is the low side. The E145 then reported an anti ice problem and need to keep up his speed. So I stopped the E145 at 5;000 because the traffic he was following on the downwind (a CRJ7) was only 4 miles in front of him at 4;000. I then turn the CRJ7 to a base heading 180 degrees. I then descend the E145 to 4;000. The E145 then stated he needed to exit icing conditions as soon as possible and wanted priority handling to the airport. I then descend the CRJ7 to 3;000 so I could have altitude between the CRJ7 and the E145 because the E145 was so much faster. I then turned the E145 to base heading and then turned him to 120 degree heading for the xxr localizer. The loss of separation was during this turn to from down wind to final on the 180 heading. The E145 the stated he needed runway yy and declared an emergency. I turned the E145 on to yy localizer. We had to pull an aircraft off of runway yy in front of the E145 because the E145 was faster. Recommendation; I would have done it the same; except maybe told the CRJ7 to descend faster to 3;000.

Original NASA ASRS Text

Title: TRACON Controller described a loss of separation event when an aircraft minimally space with other arrival traffic encountered icing and required immediate speed and altitude adjustments.

Narrative: An E145 was being vector for a Simultaneous XXR Approach. He was descending to 4;000 because XXR is the low side. The E145 then reported an anti ice problem and need to keep up his speed. So I stopped the E145 at 5;000 because the traffic he was following on the downwind (a CRJ7) was only 4 miles in front of him at 4;000. I then turn the CRJ7 to a base heading 180 degrees. I then descend the E145 to 4;000. The E145 then stated he needed to exit icing conditions ASAP and wanted priority handling to the airport. I then descend the CRJ7 to 3;000 so I could have altitude between the CRJ7 and the E145 because the E145 was so much faster. I then turned the E145 to base heading and then turned him to 120 degree heading for the XXR localizer. The loss of separation was during this turn to from down wind to final on the 180 heading. The E145 the stated he needed Runway YY and declared an emergency. I turned the E145 on to YY localizer. We had to pull an aircraft off of Runway YY in front of the E145 because the E145 was faster. Recommendation; I would have done it the same; except maybe told the CRJ7 to descend faster to 3;000.

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	935252
Time
Date	201102
Local Time Of Day	0001-0600
Place
Locale Reference	ZZZ.Airport
State Reference	US
Aircraft 1
Make Model Name	EMB ERJ 145 ER&LR
Operating Under FAR Part	Part 121
Flight Phase	Initial Approach
Route In Use	Vectors
Flight Plan	IFR
Aircraft 2
Make Model Name	Regional Jet 700 ER/LR (CRJ700)
Operating Under FAR Part	Part 121
Flight Phase	Initial Approach
Person 1
Function	Approach
Qualification	Air Traffic Control Fully Certified
Events
Anomaly	Inflight Event / Encounter Weather / Turbulence

TRACON controller described a loss of separation event when an aircraft minimally space with other arrival traffic encountered icing and required immediate speed and altitude adjustments.