A controller experienced a proximity event during a turn on to the final. The reporter thought one a...

Narrative:

This was my first day back to work. I had worked two slower sectors earlier and when told to go work 'final' at the day's busiest rush I was hesitant; but felt as if it was time. It seemed like it took a little more attention but everything was going good and I was getting into the groove. I went to clear aircraft X for the approach at 6000 feet and noticed altitude of 4700 feet. I verified altitude and gave an immediate turn away from aircraft on the other localizer. Aircraft X turned and I climbed back to 5000 feet and re-sequenced back to airport. During the turn aircraft X got 2.8 miles and 500 feet away from aircraft Y that was being turned in for the parallel runway. The controller on the other final did vector aircraft Y out to ensure separation was not lost any further. As I worked supervision listened to the recording and told me I had issued 4000 feet to aircraft X instead of 6000 feet. My only thought is that as I checked to see that the other final was at 4000 feet before I descended I still had that number in my brain and it came out instead of 6000 feet. I know there was talk about when we would go into simultaneous ILS approaches and some how I also missed the read back. It was a mistake that should have never happened. I should have swallowed my pride a little and asked for an easier position but thought everything would be fine. Supervisor advised that it was a proximity event. I said I would be filling out this report. Quick explanation: I descended an aircraft to 4000 feet that should have been issued 6000 feet. My fault and next time I will not be pressured into working busy sessions until I am 100% sure I am ready. When people come back from an extended period of time off both supervision and controller need to be responsible to make sure controller is back up to speed before working busy traffic.

Original NASA ASRS Text

Title: A Controller experienced a proximity event during a turn on to the final. The reporter thought one altitude but issued another that conflicted with parallel runway traffic.

Narrative: This was my first day back to work. I had worked two slower sectors earlier and when told to go work 'final' at the day's busiest rush I was hesitant; but felt as if it was time. It seemed like it took a little more attention but everything was going good and I was getting into the groove. I went to clear Aircraft X for the approach at 6000 feet and noticed altitude of 4700 feet. I verified altitude and gave an immediate turn away from aircraft on the other localizer. Aircraft X turned and I climbed back to 5000 feet and re-sequenced back to airport. During the turn Aircraft X got 2.8 miles and 500 feet away from Aircraft Y that was being turned in for the parallel runway. The Controller on the other final did vector Aircraft Y out to ensure separation was not lost any further. As I worked supervision listened to the recording and told me I had issued 4000 feet to Aircraft X instead of 6000 feet. My only thought is that as I checked to see that the other final was at 4000 feet before I descended I still had that number in my brain and it came out instead of 6000 feet. I know there was talk about when we would go into simultaneous ILS approaches and some how I also missed the read back. It was a mistake that should have never happened. I should have swallowed my pride a little and asked for an easier position but thought everything would be fine. Supervisor advised that it was a proximity event. I said I would be filling out this report. Quick explanation: I descended an aircraft to 4000 feet that should have been issued 6000 feet. My fault and next time I will not be pressured into working busy sessions until I am 100% sure I am ready. When people come back from an extended period of time off both supervision and controller need to be responsible to make sure controller is back up to speed before working busy traffic.

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	880810
Time
Date	201003
Local Time Of Day	0001-0600
Place
Locale Reference	DTW.Airport
State Reference	MI
Aircraft 1
Make Model Name	Large Transport
Operating Under FAR Part	Part 121
Flight Phase	Final Approach
Route In Use	Vectors
Flight Plan	IFR
Aircraft 2
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Flight Phase	Final 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

A controller experienced a proximity event during a turn on to the final. The reporter thought one altitude but issued another that conflicted with parallel runway traffic.