COMMUTER ON DSCNT HAS NMAC WITH SECOND ACFT. TCASII RA.

Narrative

WE WERE ON A 230 DEG BEARING TO DRAKE VOR AT 17 DME DSNDING OUT OF 7000 TO 3500; APCHING FAYETTEVILLE TERMINAL AREA. CONDITIONS WERE NIGHT; IFR; IMC; AND JUST HANDED OFF FROM MEMPHIS CTR TO FYV APCH (TWR). FYV CLRED US DOWN TO 3500; AND WHEN APCHING 3800 WE SAW A TARGET APCHING US ON TCASII AND INITIATED AN EVASIVE CLB MANEUVER. THE TARGET WAS ALSO CLBING AT A GOOD RATE AND WE BELIEVE HE CAME TO WITHIN 100 FT BELOW US; WITH NO LATERAL SEPARATION AS INDICATED ON TCASII. EVASIVE MANEUVER WAS INITIATED AT 900 FT VERT SEPARATION AS INDICATED ON TCASII. THE TARGET APPEARED TO BE VFR; HIGH PERFORMANCE; AND A DEP FROM SPRINGDALE; AK; AGAIN AS INDICATED BY THE DIRECTION AND PERCEIVED PERFORMANCE AS INDICATED ON TCASII. WE LEVELED OUR CLB MANEUVER AT 4500 FT; AND CONTINUED NORMALLY TO FYV WITH NO RPTED PROBLEMS FROM ATC; PAX CABIN; AND COCKPIT. THIS WAS OBVIOUSLY A VFR PLT VIOLATING PROTECTED IFR AIRSPACE IN IMC CONDITIONS; AND WE WERE STILL ON AN IFR FLT PLAN IN THIS AIRSPACE. THIS WAS VERY CLOSE; AND IS A POTENTIAL PROBLEM IN UNCTLED/NON-RADAR AIRSPACE; CLOSE PROX AIRFIELDS; AND INCREASING FAR 135 AND 121 TFC IN THE AREA.