ACR-LGT FLT CREW TOOK EVASIVE ACTION TURN TO AVOID COLLISION WITH ACR-MLG.

Narrative

LGT X WAS ON A NBOUND VECTOR SE OF ORD. WE HAD BEEN CLRED TO DSND TO 10000'; THEN RECLRED TO MAINTAIN 11000'. NEARING ORD 130 DEG/45 AREA WE NOTICED MLG Y DSNDING ON A COLLISION COURSE IN OUR 1:30 POS. A MILD RIGHT TURN WAS INITIATED TO AVOID THE TFC (AN MLG). HAD THIS HAPPENED IN IFR CONDITIONS A COLLISION WOULD HAVE BEEN HIGHLY PROBABLE AND VERY CLOSE FOR SURE. I FEEL THAT THE MAIN CAUSE OF THIS INCIDENT WAS THE FACT THAT THE CTLR WAS OVERLOADED. A REVIEW OF HIS TAPES WILL SHOW THAT HE WAS LOADED TO THE BREAKING POINT. NO HUMAN BEING CAN HANDLE MAX LOAD ALL THE TIME W/O ERRORS. THIS WAS AN EXPERIENCED CTLR ON A CLEAR DAY DOING A GREAT JOB; BUT HE WAS SO BUSY HE MADE AN ERROR. TO PUNISH OR RETRAIN THE CTLR WOULD BE TO SWEEP THIS INCIDENT UNDER THE RUG. WE HAVE A CRISIS IN ATC THAT MUST BE FACED. THIS CRISIS IS ON THE VERGE OF CRIMINAL NEGLIGENCE. IF NOTHING IS DONE TO MODERNIZE AND STAFF ATC; LETTERS OF THIS NATURE WILL DO NO GOOD. PLEASE; SOMEONE LISTEN BEFORE WE KILL ANOTHER LOAD OF PAX.