Air carrier came in close proximity to an atx while turning final approach.

Attributes
ACN	122309
Time
Date	198909
Day	Thu
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : oma
State Reference	NE
Altitude	msl bound lower : 3500 msl bound upper : 4000
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Controlling Facilities	tracon : oma
Operator	common carrier : air carrier
Make Model Name	Large Transport, Low Wing, 3 Turbojet Eng
Flight Phase	descent other
Route In Use	arrival other
Flight Plan	IFR
Aircraft 2
Operator	common carrier : air taxi
Make Model Name	Small Transport
Flight Phase	descent other
Route In Use	arrival other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : second officer
Qualification	pilot : atp pilot : flight engineer
Experience	flight time last 90 days : 220 flight time total : 4500 flight time type : 850
ASRS Report	122309
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp pilot : cfi pilot : flight engineer
Experience	flight time last 90 days : 35 flight time total : 15000 flight time type : 4700
ASRS Report	121946
Events
Anomaly	conflict : airborne less severe non adherence : published procedure non adherence : required legal separation
Independent Detector	other controllera other flight crewa
Resolutory Action	controller : issued new clearance flight crew : took evasive action
Consequence	Other
Miss Distance	horizontal : 0 vertical : 500
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error

Narrative:

As we were approaching the oma area, we were being radar vectored for an ILS 14R at 4000' MSL. The approach controller issued a heading of 020 degrees from the 060 degree heading which we had been assigned. Just as we began our turn, the approach controller issued an immediate right turn to a heading of 140 degrees. He pointed out that there was traffic at 11 O'clock at 4500' descending. Then I heard our traffic saying he was climbing up. Once we sighted our traffic, we immediately descended to 3500' MSL to avoid our traffic. During our descent, our traffic passed over us at approximately 500-600'. Supplemental information from acn 121946: incident occurred approximately 20-22 DME nnw of the oma VOR. Spoke to the controller by phone. He stated that he had lost sep.

Original NASA ASRS Text

Title: ACR CAME IN CLOSE PROX TO AN ATX WHILE TURNING FINAL APCH.

Narrative: AS WE WERE APCHING THE OMA AREA, WE WERE BEING RADAR VECTORED FOR AN ILS 14R AT 4000' MSL. THE APCH CTLR ISSUED A HDG OF 020 DEGS FROM THE 060 DEG HDG WHICH WE HAD BEEN ASSIGNED. JUST AS WE BEGAN OUR TURN, THE APCH CTLR ISSUED AN IMMEDIATE RIGHT TURN TO A HDG OF 140 DEGS. HE POINTED OUT THAT THERE WAS TFC AT 11 O'CLOCK AT 4500' DSNDING. THEN I HEARD OUR TFC SAYING HE WAS CLBING UP. ONCE WE SIGHTED OUR TFC, WE IMMEDIATELY DSNDED TO 3500' MSL TO AVOID OUR TFC. DURING OUR DSCNT, OUR TFC PASSED OVER US AT APPROX 500-600'. SUPPLEMENTAL INFO FROM ACN 121946: INCIDENT OCCURRED APPROX 20-22 DME NNW OF THE OMA VOR. SPOKE TO THE CTLR BY PHONE. HE STATED THAT HE HAD LOST SEP.

Data retrieved from NASA's ASRS site as of August 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.