TCASII. FLC FOLLOWED RA OF TCASII AND AVOIDED VFR TFC. ATC CTLR DIDN'T ALERT FLC TO TFC DUE TO OVERLOADED TFC IN SECTOR.

Narrative

DSNDING INTO DTW; WE WERE GIVEN A CLRNC DIRECT TO MIZAR; CROSS AT 12000 FT. WE LEFT 20000 FT (DSND NOW TO 18000 FT; OUR DISCRETION TO CROSS MIZAR AT 12000 FT WAS THE CLRNC). AT ABOUT 18500 FT WE GOT A TCASII 'TFC' FOLLOWED BY 'CLB; CLB.' ABOUT THE SAME TIME THE TCASII WAS GOING OFF; THE CTLR CALLED TO ADVISE US OF THE TFC. WE CLBED BACK TO 18500 FT (TCASII ADVISED TO 'MONITOR VERT SPD' OR SOMETHING LIKE THAT; AND ATC TOLD US THAT TFC WAS LEVEL AT 17500 FT'). AFTER 'CLR OF CONFLICT' WE RESUMED DSCNT. AFTER WE LANDED; I CALLED THE NUMBER GIVEN TO ME AND SPOKE WITH ACTING SUPVR OF CLE AREA #1 AND WE DISCUSSED THE SIT. WE DECIDED THAT AS THINGS GET BUSY FOR THEM; THEY GET OVERLOADED; AND LESS SIGNIFICANT THINGS BECOME OVERLOOKED (IF SOMETHING GETS 'DUMPED' IT STARTS WITH THE LEAST SIGNIFICANT). EVIDENTLY; VFR TFC SHOWS UP DIFFERENTLY ON THEIR DISPLAY BECAUSE IT IS LESS SIGNIFICANT. MY FEELING IS; THAT IF THEY GET SO OVERLOADED THAT THEY MISS A POSSIBLE MIDAIR; THE SYS IS TRYING TO DO TOO MUCH WITH TOO LITTLE; IE; STOP PUTTING SO MANY IFR ACFT IN ONE SECTOR AT A TIME. SHE WAS OVERLOADED WITH IFR ACFT AND HAD TO OVERLOOK (DUMP) THE SCAN ON THE VFR GUYS.