Sct controller experienced a loss of separation event when failing to note the slow descent of a sna...

Narrative:

I was working the tustin radar position unassisted. I was conducting visual approaches to sna runway 19R with numerous aircraft. In the area just north of the airport; I own 3000 and below and just to the north of that I own 5000 and below. My aircraft; on a visual approach; descend from 5000 and must be at 3000 or below before that airspace boundary line. The shore/maverick sector typically has airliner traffic passing southwest bound just north of the sna airport descending to 4000 landing at lgb. An A320 had been cleared for a routine visual approach and communication switched to the tower. I had previously approved a point-out on a slow-moving cessna at 3000 from an adjacent sector (shore/maverick) to transition through my airspace east to west across my final just north of the airport (sna). Simultaneously; I received a hand off from the shore/maverick sector on a VFR citation from the northwest also landing sna that was very high and fast. At the time of the hand off; the citation was about 15 miles from the airport and it's altitude was approximately 11;500; descending to 5;500; and going approximately 230 knots ground speed and heading southeast bound. I had also accepted a couple off handoffs on an IFR sna airliner arrivals from the east from the same sector descending to 6000. I was concentrating on getting the citation sequenced with the other traffic when I noticed that the A320 had significantly slowed it's descent and was unusually high; at 3300 about 4 miles from the airport. This placed the aircraft in shore's/mavericks's airspace and also in proximity to a lgb arrival that was descending to 4000. This required the shore controller to slow the descent of the lgb jet arrival and turn the cessna away. Sna tower then called and advised me that the A320 had problems and needed to go around. I assigned a right turn; heading 320; and altitude 2500. The A320 eventually diverted.

Original NASA ASRS Text

Title: SCT controller experienced a loss of separation event when failing to note the slow descent of a SNA arrival that conflicted with traffic in an adjacent sector; aircraft mechanical problems later reported as a causal factor of the slow descent.

Narrative: I was working the Tustin Radar position unassisted. I was conducting visual approaches to SNA Runway 19R with numerous aircraft. In the area just North of the airport; I own 3000 and below and just to the North of that I own 5000 and below. My aircraft; on a visual approach; descend from 5000 and must be at 3000 or below before that airspace boundary line. The Shore/Maverick sector typically has airliner traffic passing Southwest bound just north of the SNA airport descending to 4000 landing at LGB. An A320 had been cleared for a routine visual approach and communication switched to the tower. I had previously approved a point-out on a slow-moving Cessna at 3000 from an adjacent sector (Shore/Maverick) to transition through my airspace East to West across my final just north of the airport (SNA). Simultaneously; I received a hand off from the Shore/Maverick sector on a VFR Citation from the Northwest also landing SNA that was very high and fast. At the time of the hand off; the Citation was about 15 miles from the airport and it's altitude was approximately 11;500; descending to 5;500; and going approximately 230 knots ground speed and heading Southeast bound. I had also accepted a couple off handoffs on an IFR SNA airliner arrivals from the East from the same sector descending to 6000. I was concentrating on getting the Citation sequenced with the other traffic when I noticed that the A320 had significantly slowed it's descent and was unusually high; at 3300 about 4 miles from the airport. This placed the aircraft in Shore's/Mavericks's airspace and also in proximity to a LGB arrival that was descending to 4000. This required the shore controller to slow the descent of the LGB jet arrival and turn the Cessna away. SNA tower then called and advised me that the A320 had problems and needed to go around. I assigned a right turn; heading 320; and altitude 2500. The A320 eventually diverted.

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	867833
Time
Date	201001
Local Time Of Day	1801-2400
Place
Locale Reference	SCT.TRACON
State Reference	CA
Environment
Flight Conditions	VMC
Aircraft 1
Make Model Name	A320
Operating Under FAR Part	Part 121
Flight Phase	Final Approach
Route In Use	Visual Approach
Flight Plan	IFR
Aircraft 2
Make Model Name	Cessna Citation Undifferentiated or Other Model
Flight Phase	Initial Approach Descent
Person 1
Function	Approach
Qualification	Air Traffic Control Fully Certified
Events
Anomaly	Aircraft Equipment Problem Critical Airspace Violation All Types Deviation - Procedural Published Material / Policy

Sct controller experienced a loss of separation event when failing to note the slow descent of a sna arrival that conflicted with traffic in an adjacent sector; aircraft mechanical problems later reported as a causal factor of the slow descent.