VISUAL SEPARATION IN USE ACR X HAD NMAC EVASIVE ACTION TAKEN FROM KC135. SEE AND AVOID CONCEPT.

Narrative

ACR X AT CRUISE ALT OF 10000 FT ON AN IFR CLRNC AND WITH ASSIGNED HDG OF 240 DEG TALKING TO SPOKANE DEP. AT APPROX 10 MI W OF FAIRCHILD ARPT; THE CAPT (PF) SAW 1 KC135 TANKER ON TKOF ROLL AT FAIRCHILD ARPT. THE CTLR TOLD US ABOUT THE TFC JUST PRIOR TO THE CAPT SEEING THE ACFT ON THE RWY. THE CTLR ALSO TOLD US THERE WILL BE 2 TANKERS TAKING OFF. THE CAPT SAID HE ONLY SAW 1. THE CTLR WAS ALSO TALKING TO THE KC135 WHO WAS ON THE UHF FREQ. WE COULD ONLY HEAR THE CTLR'S XMISSIONS AND NOT THE KC135'S REPLY SINCE THEY WERE ON A DIFFERENT FREQ. AT SOME POINTS I THOUGHT THE CTLR WAS TALKING TO ME AND I ANSWERED ONLY TO DISCOVER HE WAS TALKING TO THE KC135. THE CTLR AGAIN POINTED OUT THE TFC AND THIS TIME THE CAPT SAID HE HAD BOTH ACFT IN SIGHT (THEY WERE ON CLBOUT JUST OFF THE RWY). THE CTLR ASKED US IF WE COULD MAINTAIN A VISUAL AND THE CAPT REPLIED YES. THE CTLR WAS COMMUNICATING BACK AND FORTH BTWN US AND THE KC135. HE WAS LETTING THEM KNOW OF OUR POS AS WELL. THE CTLR SAID WE COULD FLY ANY HDG TO STAY BEHIND THEM AND 'CAUTION WAKE TURB' AS THEY CONTINUED THEIR CLB. JUST AS HE SAID THAT THE FIRST KC135 TURNED SHARPLY TO THE R AS HE CONTINUED HIS CLB TURNING R TOWARDS OUR FLT PATH. THE CAPT QUICKLY MADE A SHARP CLBING L TURN TO GET OUT OF THE WAY OF THE ACFT. WE SHOT THROUGH OUR ASSIGNED HDG OF 180 DEG TO ABOUT 150 DEG AND WE WERE 500 FT HIGHER THAN OUR ASSIGNED ALT. THE PROB HERE WAS THAT THE KC135 WAS ON A DIFFERENT FREQ THEREFORE WE WERE NOT GETTING THE WHOLE PICTURE. WE DIDN'T KNOW HE WAS GOING TO MAKE THE SHARP R TURN UNTIL HE DID. IT WOULD ALSO HAVE HELPED IF BOTH US WERE EQUIPPED WITH TCASII BECAUSE IT'S HARD TO JUDGE HOW FAR AWAY AN ACFT IS UNTIL IT'S REALLY CLOSE.