2 DH8 ACFT APPLYING VISUAL SEPARATION DURING CLB AND DSCNT MANEUVER RESULT IN TCASII WHILE UNDER ZSE CTL.

Narrative

ACFT #1 DEPARTED LWS NBOUND AND CLRED VIA AIRWAY CLBING TO THE MEA OF 6000 FT. ACFT #2 WAS INBOUND FROM THE N AND LEVEL AT 7000 FT. ACFT #1 RPTED ACFT #2 IN SIGHT DURING DEP CLBOUT. IMMEDIATELY AFTER; ACFT #2 RPTED ACFT #1 IN SIGHT ALONG WITH THE ARPT IN SIGHT. ACFT #2 WAS CLRED FOR VISUAL APCH WITH RESTR TO MAINTAIN VISUAL SEPARATION FROM ACFT #1. ACFT #1 WAS ADVISED ACFT #2 WAS ON VISUAL APCH AND MAINTAINING VISUAL SEPARATION. ACFT #1 ADVISED THEY STILL HAD ACFT #2 IN SIGHT. WHEN BOTH ACFT WERE WITHIN 2 MI OF EACH OTHER; A VOICE ON FREQ SAID SOMETHING TO THE EFFECT OF 'WHAT ARE YOU GUYS DOING?' A SECOND VOICE SAID SOMETHING LIKE 'WE'RE GOING AROUND YOU; WHAT ARE YOU WORRIED ABOUT?' A FEW SECONDS LATER; ACFT #1 ADVISED 'RESPONDING TO RA.' IT APPEARED BOTH ACFT MOVED HORIZLY AND ACFT #1 DSNDED TO NEAR 5000 FT. THE MINIMUM IFR ALT I COULD ASSIGN IN THIS AREA IS ALSO 5000 FT. THERE WERE 2-3 OTHER ACFT ON FREQ. I HAVE A FEW CONCERNS WITH THIS INCIDENT. WHEN I CLR AN ACFT TO MAINTAIN VISUAL SEPARATION; HOW THAT ACFT PLANS TO PROVIDE VISUAL SEPARATION IS UNKNOWN. WILL THEY TURN L; R; CLB; DSND; OR LEVEL OFF? THE OTHER ACFT AND MYSELF ARE LEFT GUESSING. SECOND; WHEN ACFT #2 STATES 'RESPONDING TO RA;' I AM ALSO UNINFORMED WHETHER THEY WILL CLB OR DSND. EVEN IF ACFT #2 STATES THEY ARE DSNDING; THE QUESTIONS BEGS; 'HOW FAR WILL THIS ACFT DSND?' TERRAIN AND/OR MY MINIMUM IFR ALT COULD HAVE BEEN A FACTOR IN THE EVENTS THAT TRANSPIRED IN SECONDS. MY NOT APPLYING VISUAL SEPARATION AND KEEPING BOTH ACFT VERTLY SEPARATED UNTIL CLR COULD HAVE RESOLVED THE SIT. HOWEVER; THIS WOULD HAVE CAUSED DELAY TO THE ARRIVING FLT BY KEEPING THEM HIGH UNTIL VERY NEAR THE LNDG ARPT. COM BY THE ARRIVING ACFT OF HOW IT PLANNED TO APPLY VISUAL SEPARATION WOULD HAVE BEEN USEFUL TO THE OTHER PLT AND MYSELF. INSTEAD; IT BECAME LAST SECOND XMISSIONS AND ACTIONS. THE EXTREME STRESS I ENDURED DURING THIS INCIDENT COULD HAVE ONLY BEEN EXCEEDED BY THE 2 CREWS.