Operating in mvf conditions encountered an small transport VFR, same direction, same altitude.

Attributes
ACN	90110
Time
Date	198807
Day	Sat
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : vuz
State Reference	AL
Altitude	msl bound lower : 10800 msl bound upper : 11000
Environment
Flight Conditions	Marginal
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : ztl
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Flight Phase	descent other
Flight Plan	IFR
Aircraft 2
Make Model Name	Small Transport, Low Wing, 2 Recip Eng
Flight Phase	cruise other
Flight Plan	VFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp pilot : cfi pilot : flight engineer pilot : instrument pilot : private
Experience	flight time last 90 days : 200 flight time total : 9800 flight time type : 4000
ASRS Report	90110
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument
Events
Anomaly	altitude deviation : excursion from assigned altitude conflict : nmac
Independent Detector	other flight crewa
Resolutory Action	flight crew : took evasive action
Consequence	Other
Miss Distance	horizontal : 300 vertical : 200
Supplementary
Primary Problem	Flight Crew Human Performance

Narrative:

During descent for arrival, inbound to bhm from msy, we leveled at 11000. We had just been handed off to atl center (I think) from columbus approach control. I saw an small transport at 11 O'clock, 1/4 mi, 11000', same direction. I took control of the aircraft, descended to 10800' (advising ATC of deviation) and flew by the VFR aircraft about 500' away. ARTCC was not aware of the traffic as they said I was not in their airspace quite yet.

Original NASA ASRS Text

Title: OPERATING IN MVF CONDITIONS ENCOUNTERED AN SMT VFR, SAME DIRECTION, SAME ALT.

Narrative: DURING DSCNT FOR ARRIVAL, INBND TO BHM FROM MSY, WE LEVELED AT 11000. WE HAD JUST BEEN HANDED OFF TO ATL CENTER (I THINK) FROM COLUMBUS APCH CTL. I SAW AN SMT AT 11 O'CLOCK, 1/4 MI, 11000', SAME DIRECTION. I TOOK CONTROL OF THE ACFT, DESCENDED TO 10800' (ADVISING ATC OF DEVIATION) AND FLEW BY THE VFR ACFT ABOUT 500' AWAY. ARTCC WAS NOT AWARE OF THE TFC AS THEY SAID I WAS NOT IN THEIR AIRSPACE QUITE YET.

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.