ZAU controller described near loss of separation event while sequencing multiple arrivals into tjbq;...

Narrative:

Air carrier X inbound to tjbq airport from the south. Air carrier Y inbound to bqn from south. Air carrier Z inbound to tjbq from the east. I lost radar contact on air carrier Y when he was on approach. My plan was to have air carrier X follow him into the airport but he was to slow; he was at 5000 ft. I had air carrier Z at 9000 ft and decided to put him in front of air carrier X. I descended him to 4000 ft; while trying to sequence him behind and aircraft I cannot see. When he started his descent to 4000 ft to get below air carrier X I saw that it was not going to work so I told air carrier X about air carrier Z. He reported traffic in site at about 5.5 miles. I then instructed him to maintain visual separation from the traffic. The air carrier Z stopped at 5000 ft so they started to converge. I then took action to turn the airplanes apart giving both 30 degree turns away from each other. After regaining control of the situation all airplanes were sequenced into bqn with no further incident. The real problem lies in the fact every night we have about 15 to 24 airplanes returning from outlying fields back to tjbq. They all arrive at the same time. We work a very large sector which is way to big to control. When we need to concentrate just on that particular problem. A new satellite sector needs to be opened in order to sequence the planes into tjbq airport at this time of night. We have many factors such as weather and frequency congestion to attend too.

Original NASA ASRS Text

Title: ZAU controller described near loss of separation event while sequencing multiple arrivals into TJBQ; listing airspace size and traffic volume as casual factors.

Narrative: Air Carrier X inbound to TJBQ airport from the South. Air Carrier Y inbound to BQN from South. Air Carrier Z inbound to TJBQ from the East. I lost radar contact on Air Carrier Y when he was on approach. My plan was to have Air Carrier X follow him into the airport but he was to slow; he was at 5000 FT. I had Air Carrier Z at 9000 FT and decided to put him in front of Air Carrier X. I descended him to 4000 FT; while trying to sequence him behind and aircraft I cannot see. When he started his descent to 4000 FT to get below Air Carrier X I saw that it was not going to work so I told Air Carrier X about Air Carrier Z. He reported traffic in site at about 5.5 miles. I then instructed him to maintain visual separation from the traffic. The Air Carrier Z stopped at 5000 FT so they started to converge. I then took action to turn the airplanes apart giving both 30 degree turns away from each other. After regaining control of the situation all airplanes were sequenced into BQN with no further incident. The real problem lies in the fact every night we have about 15 to 24 airplanes returning from outlying fields back to TJBQ. They all arrive at the same time. We work a very large sector which is way to big to control. When we need to concentrate just on that particular problem. A new satellite sector needs to be opened in order to sequence the planes into TJBQ airport at this time of night. We have many factors such as weather and frequency congestion to attend too.

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	847104
Time
Date	200908
Local Time Of Day	1801-2400
Place
Locale Reference	ZSU.ARTCC
State Reference	PR
Aircraft 1
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Flight Phase	Descent
Flight Plan	IFR
Aircraft 2
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Flight Phase	Descent
Person 1
Function	Enroute
Qualification	Air Traffic Control Fully Certified
Experience	Air Traffic Control Military 10 Air Traffic Control Non Radar 8 Air Traffic Control Radar 8
Events
Anomaly	Conflict Airborne Conflict

ZAU controller described near loss of separation event while sequencing multiple arrivals into tjbq; listing airspace size and traffic volume as casual factors.