C90 CTLR DESCRIBED INCIDENT WHEN BOTH ACFT ON SIMULTANEOUS APCHS TO RWY 9L AND RWY 9R WENT AROUND DUE TO AN INAPPROPRIATE TWR CLRNC.

Narrative

SIMUL RWY 9R AND RWY 9L APCHS AT ORD. A B767 SLOWED BEFORE THE OM. THIS IS A VIOLATION OF ATC INSTRUCTIONS VERIFIED VIA RADIO WITH THE PLT. A CRJ7 WAS GAINING ON THE B767. I INSTRUCTED THE B767 TO EXECUTE MISSED APCH. ORD TWR IMMEDIATELY COUNTERMANDED MY MISSED APCH INSTRUCTIONS AND ADVISED THE B767 TO CONTINUE. I THEN INSTRUCTED THE CRJ7 TO EXECUTE MISSED APCH DUE TO INSUFFICIENT WAKE TURB SEPARATION. THE B767 THEN ADVISED ORD TWR THAT HE COULD NOT LAND; MOST LIKELY DUE TO CONFUSION IN THE COCKPIT; CREATED BY ORD TWR. THE RESULT WAS THAT ORD TWR NOW HAD 2 MISSED APCHS. THE B767 HAD TO DSND FROM 3400 FT ON HIS WAY TO 4000 FT; BACK DOWN TO 3000 FT; IN ORDER TO STAY BELOW THE CRJ7 THAT WAS ALREADY AT 4000 FT ON THEIR MISSED APCH. ORD TWR; BY COUNTERMANDING MY INSTRUCTIONS; CREATED AN EXTREMELY UNSAFE SITUATION AND CAUSED AN UNNECESSARY DELAY TO THE CRJ7. AS A SIDE NOTE: I WAS WORKING THE PARALLEL MONITOR POS. MY AIRSPACE BEGINS AT 22 MI AND CONTINUES TO 1 MI FINAL. ONCE AN ACFT IS TOLD TO EXECUTE MISSED APCH; IT SHOULD NOT BE CHANGED. THE PARALLEL MONITOR HAS AUTH FOR AIRSPACE TO 1 MI FINAL.