Air carrier has near midair collision with small transport while on profile descent.

Attributes
ACN	226562
Time
Date	199211
Day	Fri
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : lax
State Reference	CA
Altitude	msl bound lower : 15000 msl bound upper : 15000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : lax
Operator	common carrier : air carrier
Make Model Name	Large Transport, Low Wing, 2 Turbojet Eng
Navigation In Use	Other Other
Flight Phase	descent : approach
Route In Use	arrival : profile descent
Flight Plan	IFR
Aircraft 2
Make Model Name	Small Aircraft
Flight Phase	cruise other
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : cfi pilot : commercial pilot : flight engineer pilot : instrument pilot : atp
Experience	flight time last 90 days : 210 flight time total : 15000 flight time type : 700
ASRS Report	226562
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Events
Anomaly	conflict : nmac other anomaly other other anomaly other
Independent Detector	other flight crewa
Resolutory Action	flight crew : took evasive action
Consequence	Other
Miss Distance	horizontal : 500 vertical : 0
Supplementary
Primary Problem	Flight Crew Human Performance

Narrative:

Our flight was iad to lax. Cleared profile descent (civet 3). 11 mi east of civet intersection, ATC issued TA, had us maintain 15000 ft. Converging VFR traffic at our 9 O'clock position, same altitude was heading northwest. It was at 500 ft horizontal distance when we saw this small transport. It then rolled over, started a steep descent to avoid us. We had no time to react and continued our approach without incident. We did not have TCASII aboard this aircraft.

Original NASA ASRS Text

Title: ACR HAS NMAC WITH SMT WHILE ON PROFILE DSCNT.

Narrative: OUR FLT WAS IAD TO LAX. CLRED PROFILE DSCNT (CIVET 3). 11 MI E OF CIVET INTXN, ATC ISSUED TA, HAD US MAINTAIN 15000 FT. CONVERGING VFR TFC AT OUR 9 O'CLOCK POS, SAME ALT WAS HDG NW. IT WAS AT 500 FT HORIZ DISTANCE WHEN WE SAW THIS SMT. IT THEN ROLLED OVER, STARTED A STEEP DSCNT TO AVOID US. WE HAD NO TIME TO REACT AND CONTINUED OUR APCH WITHOUT INCIDENT. WE DID NOT HAVE TCASII ABOARD THIS ACFT.

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.