LNDG MD90 AT ORD ENCOUNTERS WAKE TURB BEHIND B747.

Narrative

OUR FLT WAS BEING VECTORED BY ORD APCH CTL AS WE WERE BEING SEQUENCED 5 MI BEHIND A HVY B747 ACCORDING TO OUR TCASII DISPLAY. WE FIRST ENCOUNTERED SOME OF THE B747'S WASH WHILE ON BASE WITH OUR ASSIGNED SPD OF 210 KTS. JUST AS WE WERE GOING TO CONTACT OUR CTLR FOR A SLOWER SPD FOR SPACING; HE WAS ALREADY IN THE PROCESS OF CONTACTING US WITH THE SLOWER SPD OF 180 KTS. THIS HELPED TO COUNTER THE WASH. AS WE TURNED ONTO FINAL AND WERE CLRED FOR THE RWY 9R APCH; WE WERE ASSIGNED A TWR FREQ; HOWEVER; DURING THIS XMISSION; WE ENCOUNTERED HEAVIER WASH THAT TURNED INTO MODERATE TURB. FOR SAFETY OF FLT; I HAD THE FO SLOW THE ACFT DOWN FOR SPACING ALONG WITH A PWR ADDITIVE SO AS TO HELP STABILIZE OUR SIT AS WE KEPT THE WINGS LEVEL. THE WAKE TURB LASTED APPROX 15 SECONDS AND OUR APCH CTLR WAS EXTREMELY BUSY ON OUR FREQ AND WE WERE NOT ABLE TO GET IN 3 DIFFERENT XMISSIONS AS HE MAINTAINED A CONTINUOUS 1-WAY COMS STREAM WITHOUT COMPLETE FEEDBACK. SINCE WE WERE PREVIOUSLY ASSIGNED THE TWR FREQ; WE WENT OVER TO THEM ONLY TO BE TOLD THAT OUR APCH CTLR NEEDED US BACK ON HIS FREQ. WE RETURNED AND WERE IMMEDIATELY CHIDED BY HIM WITH 'MUST BE NICE TO DO ANYTHING THAT YOU LIKE.' AS I DISCUSSED WITH THE ORD APCH SUPVR OVER THE TELEPHONE AFTER WE HAD ARRIVED AT OUR GATE; THERE WERE NO COMPLETE XMISSIONS TO OUR CTLR NOR TO US AS THIS SIT LATER REVEALED BECAUSE OF THEIR EXCESSIVE COM DEMANDS. I WAS LATER TOLD THAT THE CTLR HAD WANTED TO TAKE US OUT OF THE PATTERN AND I THEN TOLD THE SUPVR THAT THIS WAS NOT PRACTICAL SINCE IT WAS NECESSARY TO KEEP OUR WINGS LEVEL UNTIL WE HAD STABILIZED FLT CONDITIONS.