Air carrier X had less than standard separation from air carrier Y. Possible system error.

Attributes
ACN	180451
Time
Date	199105
Day	Wed
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : hec
State Reference	CA
Altitude	msl bound lower : 28400 msl bound upper : 29000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zla tracon : mfd
Operator	common carrier : air carrier
Make Model Name	Large Transport, Low Wing, 2 Turbojet Eng
Navigation In Use	Other Other
Flight Phase	cruise other
Route In Use	enroute : on vectors
Flight Plan	IFR
Aircraft 2
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Flight Phase	descent other
Route In Use	enroute : direct
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Experience	flight time last 90 days : 200 flight time total : 6000 flight time type : 500
ASRS Report	180451
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	conflict : airborne less severe non adherence : published procedure non adherence : required legal separation
Independent Detector	aircraft equipment other aircraft equipment : unspecified
Resolutory Action	controller : issued new clearance other
Consequence	Other
Miss Distance	horizontal : 27000 vertical : 600
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error

Narrative:

Air carrier X at FL290 on our filed flight plan. Los angeles center said 'turn right heading 070 degree'. TCAS called 'traffic' and showed an aircraft at 12 O'clock just inside 5 mi, altitude 600 ft below and descending. We located air carrier Y visually as los angeles center asked it to expedite its descent. 15 seconds after issuing the 070 degree heading we were cleared direct to bld. TCAS showed the aircraft 1000 ft below our altitude.

Original NASA ASRS Text

Title: ACR X HAD LTSS FROM ACR Y. POSSIBLE SYS ERROR.

Narrative: ACR X AT FL290 ON OUR FILED FLT PLAN. LOS ANGELES CENTER SAID 'TURN RIGHT HDG 070 DEG'. TCAS CALLED 'TFC' AND SHOWED AN ACFT AT 12 O'CLOCK JUST INSIDE 5 MI, ALT 600 FT BELOW AND DSNDING. WE LOCATED ACR Y VISUALLY AS LOS ANGELES CENTER ASKED IT TO EXPEDITE ITS DSCNT. 15 SECONDS AFTER ISSUING THE 070 DEG HDG WE WERE CLRED DIRECT TO BLD. TCAS SHOWED THE ACFT 1000 FT BELOW OUR ALT.

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.