Aus controller described a near separation loss event when required in trail distance was minimal an...

Narrative:

I had several arrivals and was doing ILS approaches to runway 17L/17R. I had an EA45 doing practice approaches. The pilot was a student and I had difficulty with them on every approach. They were on a right downwind to runway 17R and I turned them to a heading of 010 to get closer to the turn on point. The pilot was a student and they turned to a 100 or 110 heading; well inside the turn on point. When I realized they had turned too far; I climbed them and turned them southbound. I believe this was a pilot deviation; although I do not recall the read back of the assigned heading. I had numerous other arrivals and this messed up my sequence and threw me off. It put them in a bad place on final and my mind was trying to figure out where to re-sequence them. I had altitude with everyone; but there were more arrivals still coming. I sequenced a few more aircraft and had a BE35 for 17L behind; I think; a regional jet. I kept altitude as long as I could and then finally cleared the bonanza for the ILS approach anticipating that he would slow down and my 3+ miles would become 4 miles. Although I kept slowing the bonanza down; the space between them did not spread out as much as I had anticipated. When the rj was at the threshold it did not appear to be quite four miles so I asked the supervisor if I should break the bonanza out and he/she said yes. I issued climb instructions and tried to turn him but; he said he had the airport in sight. I cleared him for a visual approach and then at the prompting of the supervisor made sure he also had the rj in sight and told him to maintain visual separation. Partially; I was hesitant to send him around because I had planes stacking up and the EA45 was also out there that I had to re-sequence. I think once the EA45 proved difficult; I should have ended his approaches and sent him on his way. I'm not sure what the separation was with the bonanza and the jet on final. Recommendation: 1. End practice approaches to aircraft when it becomes busy; especially student pilots who are having a difficult time. 2. Don't hesitate to break out aircraft on final with overtake; even if it is 'just' a bonanza. 3. Don't take hand offs from feeders until I have somewhere to put more arrivals.

Original NASA ASRS Text

Title: AUS Controller described a near separation loss event when required in trail distance was minimal and visual separation was necessary; the reporter noting the need to curtail some ATC action when traffic dictates.

Narrative: I had several arrivals and was doing ILS approaches to Runway 17L/17R. I had an EA45 doing practice approaches. The pilot was a student and I had difficulty with them on every approach. They were on a right downwind to Runway 17R and I turned them to a heading of 010 to get closer to the turn on point. The pilot was a student and they turned to a 100 or 110 heading; well inside the turn on point. When I realized they had turned too far; I climbed them and turned them southbound. I believe this was a pilot deviation; although I do not recall the read back of the assigned heading. I had numerous other arrivals and this messed up my sequence and threw me off. It put them in a bad place on final and my mind was trying to figure out where to re-sequence them. I had altitude with everyone; but there were more arrivals still coming. I sequenced a few more aircraft and had a BE35 for 17L behind; I think; a regional jet. I kept altitude as long as I could and then finally cleared the Bonanza for the ILS approach anticipating that he would slow down and my 3+ miles would become 4 miles. Although I kept slowing the Bonanza down; the space between them did not spread out as much as I had anticipated. When the RJ was at the threshold it did not appear to be quite four miles so I asked the Supervisor if I should break the Bonanza out and he/she said yes. I issued climb instructions and tried to turn him but; he said he had the airport in sight. I cleared him for a visual approach and then at the prompting of the Supervisor made sure he also had the RJ in sight and told him to maintain visual separation. Partially; I was hesitant to send him around because I had planes stacking up and the EA45 was also out there that I had to re-sequence. I think once the EA45 proved difficult; I should have ended his approaches and sent him on his way. I'm not sure what the separation was with the Bonanza and the jet on final. Recommendation: 1. End practice approaches to aircraft when it becomes busy; especially student pilots who are having a difficult time. 2. Don't hesitate to break out aircraft on final with overtake; even if it is 'just' a Bonanza. 3. Don't take hand offs from feeders until I have somewhere to put more arrivals.

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	918886
Time
Date	201011
Local Time Of Day	1801-2400
Place
Locale Reference	AUS.TRACON
State Reference	TX
Aircraft 1
Make Model Name	Bonanza 35
Flight Phase	Descent
Route In Use	Other Instrument 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

Aus controller described a near separation loss event when required in trail distance was minimal and visual separation was necessary; the reporter noting the need to curtail some ATC action when traffic dictates.