Phl TRACON controller experienced operational error at approximately 4000 ft during downwind vector ...

Attributes
ACN	634326
Time
Date	200410
Day	Fri
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : phl.airport
State Reference	PA
Altitude	msl bound lower : 3400 msl bound upper : 4200
Environment
Flight Conditions	IMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : phl.tracon
Operator	common carrier : air carrier
Make Model Name	B737 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	descent : intermediate altitude
Route In Use	approach : traffic pattern arrival : on vectors
Flight Plan	IFR
Aircraft 2
Controlling Facilities	tracon : phl.tracon
Operator	common carrier : air carrier
Make Model Name	Regional Jet CL65, Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	descent : intermediate altitude descent : approach
Route In Use	arrival : on vectors
Flight Plan	IFR
Person 1
Affiliation	government : faa
Function	controller : approach
Qualification	controller : non radar controller : radar
Experience	controller non radar : 15 controller radar : 6
ASRS Report	634320
Person 2
Affiliation	government : faa
Function	controller : handoff position
Qualification	controller : radar
Experience	controller radar : 15
ASRS Report	634327
Events
Anomaly	conflict : airborne less severe non adherence : required legal separation
Independent Detector	atc equipment : conflict alert other controllera other controllerb
Resolutory Action	controller : issued new clearance controller : issued alert flight crew : took evasive action
Consequence	faa : investigated
Miss Distance	vertical : 800
Supplementary
Problem Areas	ATC Human Performance
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error

Narrative:

I descended an air carrier X jet from 6000 ft to 4000 ft on a right downwind to runway 9R. I observed an air carrier Y jet that I had just taken the handoff also on the downwind climbing out of 3000 ft. I then turned air carrier X northbound to avoid possible conflict. Supplemental information from acn 634327: I turned air carrier Y right to heading 265 degrees, and climbed him to 4000 ft to help fvi out. I noticed that fvi was busy enough that air carrier Y could conceivably enter airspace in which fvi only owned 4000-6000 ft. I did notice traffic at 6000 ft directly on top of air carrier Y. The conflict alert went off soon after that, indication that the aircraft that was directly over air carrier Y was descending. I then descended air carrier Y back to 3000 ft. The result was a loss of separation as indicated on this report.

Original NASA ASRS Text

Title: PHL TRACON CTLR EXPERIENCED OPERROR AT APPROX 4000 FT DURING DOWNWIND VECTOR FOR RWY 9R.

Narrative: I DSNDED AN ACR X JET FROM 6000 FT TO 4000 FT ON A R DOWNWIND TO RWY 9R. I OBSERVED AN ACR Y JET THAT I HAD JUST TAKEN THE HDOF ALSO ON THE DOWNWIND CLBING OUT OF 3000 FT. I THEN TURNED ACR X NBOUND TO AVOID POSSIBLE CONFLICT. SUPPLEMENTAL INFO FROM ACN 634327: I TURNED ACR Y R TO HDG 265 DEGS, AND CLBED HIM TO 4000 FT TO HELP FVI OUT. I NOTICED THAT FVI WAS BUSY ENOUGH THAT ACR Y COULD CONCEIVABLY ENTER AIRSPACE IN WHICH FVI ONLY OWNED 4000-6000 FT. I DID NOTICE TFC AT 6000 FT DIRECTLY ON TOP OF ACR Y. THE CONFLICT ALERT WENT OFF SOON AFTER THAT, INDICATION THAT THE ACFT THAT WAS DIRECTLY OVER ACR Y WAS DSNDING. I THEN DSNDED ACR Y BACK TO 3000 FT. THE RESULT WAS A LOSS OF SEPARATION AS INDICATED ON THIS RPT.

Data retrieved from NASA's ASRS site as of July 2007 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.

Phl TRACON controller experienced operational error at approximately 4000 ft during downwind vector for runway 9R.