MLG TAKES EVASIVE ACTION DUE TCASII TA THEN RA.

Narrative

WE WERE CRUISING AT 17000 FT MSL. WE GOT A TCASII TA; I WAS THE PNF. I REACHED DOWN AND SELECTED THE 5 MI SCALE ON THE TCASII UNIT. THE TA IMMEDIATELY CHANGED TO AN RA. THE RA COMMANDED CLB. I INDICATED TO THE FO WHO WAS FLYING TO CLB AS I SHOVED THE PWR LEVERS FORWARD. WE CLBED TO 18000 FT MSL AT WHICH TIME WE WERE ISSUED A CLR OF CONFLICT BY THE TCASII. WE RETURNED TO 17000 FT MSL. THE CTLR SAID THAT THE TFC WAS VFR AT 16500 FT. SUPPLEMENTAL INFO FROM ACN 289191: PASSING ABOUT 17500 FT IN THE CLB I SPOTTED THE TFC AT R 2-3 O'CLOCK POS; SLIGHTLY LOWER THAN US ABOUT 2000 FT AWAY. THE DISTANCE AND ALT WERE DIFFICULT TO JUDGE SINCE I CAUGHT ONLY A GLIMPSE OF SOME TYPE OF TWIN WHICH I WASN'T ABLE TO RECOGNIZE; BUT IT DID SEEM TO BE MUCH CLOSER TO THE ALT WE HAD VACATED THAN I EXPECTED. THE CAPT TOLD ATC WHAT WE WERE DOING DURING THE MANEUVER; AND WE RECEIVED HIS CONCURRENCE TO DSND TO 17000 FT FOLLOWING THE TCASII RA. NO ADDITIONAL TFC CONFLICTS WERE MENTIONED BY ATC OR NOTICED BY THE COCKPIT CREW DURING THE INCIDENT.