Air carrier X had less than standard separation from air carrier Y. System error. TCASII TA RA evasi...

Attributes
ACN	184022
Time
Date	199107
Day	Thu
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : phl
State Reference	PA
Altitude	msl bound lower : 3000 msl bound upper : 3000
Environment
Flight Conditions	Marginal
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : phl tower : dpa
Operator	common carrier : air carrier
Make Model Name	Large Transport, Low Wing, 3 Turbojet Eng
Flight Phase	descent : approach
Flight Plan	IFR
Aircraft 2
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Flight Phase	climbout : intermediate altitude
Route In Use	enroute : on vectors
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 225 flight time total : 16200 flight time type : 10000
ASRS Report	184022
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Events
Anomaly	altitude deviation : undershoot conflict : airborne less severe non adherence : published procedure non adherence : clearance non adherence : required legal separation
Independent Detector	aircraft equipment other aircraft equipment : unspecified
Resolutory Action	flight crew : took evasive action
Consequence	faa : reviewed incident with flight crew
Miss Distance	horizontal : 12000 vertical : 300
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error

Narrative:

Air carrier X was on vectors for ILS runway 27R. We were told to turn left heading 290 degree from over heading 360 degree and intercept 27R localizer and cleared for approach runway 27R cross OM 2100 or above. We started a descent from 3000 ft. At about 2800 ft we got a TA for traffic. It showed about 1 O'clock about 5 mi and 800 ft below. I stopped descent. At this time we got an RA to climb at 2000 FPM. I climbed to about 3250 ft and air carrier Y passed under by about 300 ft and 2 mi away. First officer told approach control of RA maneuver and he vectored us for another approach. I called approach control. I talked to supervisor on duty. He said that the controller working air carrier X thought the separation was sufficient with our vector for approach. He said maybe his radar was late in tracking the flts. I asked if he thought we did what we should have because of the RA and he said yes.

Original NASA ASRS Text

Title: ACR X HAD LTSS FROM ACR Y. SYS ERROR. TCASII TA RA EVASIVE ACTION TAKEN.

Narrative: ACR X WAS ON VECTORS FOR ILS RWY 27R. WE WERE TOLD TO TURN L HDG 290 DEG FROM OVER HDG 360 DEG AND INTERCEPT 27R LOC AND CLRED FOR APCH RWY 27R CROSS OM 2100 OR ABOVE. WE STARTED A DSCNT FROM 3000 FT. AT ABOUT 2800 FT WE GOT A TA FOR TFC. IT SHOWED ABOUT 1 O'CLOCK ABOUT 5 MI AND 800 FT BELOW. I STOPPED DSCNT. AT THIS TIME WE GOT AN RA TO CLB AT 2000 FPM. I CLBED TO ABOUT 3250 FT AND ACR Y PASSED UNDER BY ABOUT 300 FT AND 2 MI AWAY. FO TOLD APCH CTL OF RA MANEUVER AND HE VECTORED US FOR ANOTHER APCH. I CALLED APCH CTL. I TALKED TO SUPVR ON DUTY. HE SAID THAT THE CTLR WORKING ACR X THOUGHT THE SEPARATION WAS SUFFICIENT WITH OUR VECTOR FOR APCH. HE SAID MAYBE HIS RADAR WAS LATE IN TRACKING THE FLTS. I ASKED IF HE THOUGHT WE DID WHAT WE SHOULD HAVE BECAUSE OF THE RA AND HE SAID YES.

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.

Air carrier X had less than standard separation from air carrier Y. System error. TCASII TA RA evasive action taken.