Bizjet, IFR, has near midair collision with commuter light transport, VFR.

Attributes
ACN	138037
Time
Date	199002
Day	Tue
Local Time Of Day	1801 To 2400
Place
Locale Reference	atc facility : gvo
State Reference	CA
Altitude	msl bound lower : 9000 msl bound upper : 9000
Environment
Flight Conditions	Marginal
Light	Night
Aircraft 1
Controlling Facilities	artcc : zla
Operator	common carrier : air taxi
Make Model Name	Light Transport, Low Wing, 2 Turbojet Eng
Navigation In Use	Other
Flight Phase	cruise other descent other
Route In Use	enroute : on vectors
Flight Plan	IFR
Aircraft 2
Operator	common carrier : air carrier
Make Model Name	Light Transport, Low Wing, 2 Turboprop Eng
Flight Phase	cruise other
Flight Plan	VFR
Person 1
Affiliation	Other
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial pilot : atp
Experience	flight time last 90 days : 100 flight time total : 5000 flight time type : 150
ASRS Report	138037
Person 2
Affiliation	Other
Function	flight crew : captain oversight : pic
Qualification	pilot : atp pilot : instrument pilot : commercial
Events
Anomaly	conflict : nmac other anomaly other
Independent Detector	other flight crewa
Resolutory Action	flight crew : took evasive action
Consequence	Other
Miss Distance	horizontal : 300 vertical : 100
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

On our descent to ksba from FL390 ZLA asked us (light transport X) to level at 9000 MSL. He called traffic at 10 O'clock, an light transport Y on top at 10.5 MSL had you in sight will maintain visual with you. We were looking, 'not in sight'. A few moments later we saw traffic at short range. Both aircraft took evasive action by making steep left turns. The pilot from the light transport Y then apologized (admitting guilt) about the close call. My feeling is the pilots in the Y never had us in sight, possibly they were looking at another aircraft. I feel that during these 'maintain visual separation' situations with only 1 aircraft having the other in sight, puts the second aircraft in jeopardy. I can only recommend that this practice be safe if both aircraft have each other in sight.

Original NASA ASRS Text

Title: BIZJET, IFR, HAS NMAC WITH COMMUTER LTT, VFR.

Narrative: ON OUR DSCNT TO KSBA FROM FL390 ZLA ASKED US (LTT X) TO LEVEL AT 9000 MSL. HE CALLED TFC AT 10 O'CLOCK, AN LTT Y ON TOP AT 10.5 MSL HAD YOU IN SIGHT WILL MAINTAIN VISUAL WITH YOU. WE WERE LOOKING, 'NOT IN SIGHT'. A FEW MOMENTS LATER WE SAW TFC AT SHORT RANGE. BOTH ACFT TOOK EVASIVE ACTION BY MAKING STEEP LEFT TURNS. THE PLT FROM THE LTT Y THEN APOLOGIZED (ADMITTING GUILT) ABOUT THE CLOSE CALL. MY FEELING IS THE PLTS IN THE Y NEVER HAD US IN SIGHT, POSSIBLY THEY WERE LOOKING AT ANOTHER ACFT. I FEEL THAT DURING THESE 'MAINTAIN VISUAL SEPARATION' SITUATIONS WITH ONLY 1 ACFT HAVING THE OTHER IN SIGHT, PUTS THE SECOND ACFT IN JEOPARDY. I CAN ONLY RECOMMEND THAT THIS PRACTICE BE SAFE IF BOTH ACFT HAVE EACH OTHER IN SIGHT.

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.