AN ACR B737 HITS THE WAKE OF A B727 DURING AN APCH. THE RPTR FEELS THAT THE WAKE EFFECT WAS ENHANCED BECAUSE HE HAD THE SPD BRAKES EXTENDED.

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WE WERE BEING VECTORED TO AN ILS APCH TO RWY 27 AT IAH. WE WERE TOLD TO KEEP 250 KTS UNTIL TURNING FINAL. WE WERE APPROX 3 MI BEHIND AND ABOVE A COMPANY B727. I HAD SPD BRAKES OUT TO HELP SLOW AND DSND TO 2000 FT MSL. AT APPROX 5000 FT WE ENCOUNTERED THE B727'S WAKE TURB. THE ACFT ROLLED L TO APPROX 20-30 DEGS. THE AUTOPLT WAS ON AS WELL AS AUTOTHROTTLES. THE ROLL RATE WAS BRISK DUE TO SPD BRAKES BEING OUT. THE AUTOPLT TRIED TO ROLL R AND IT DID (BRISKLY) TO APPROX 15 DEGS R. I PROMPTLY DISCONNECTED THE AUTOPLT AND CORRECTED WITH AILERON AND RUDDER AND THEN RESECURED THE SPD BRAKES. FLT LANDED UNEVENTFULLY. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR WAS FLYING A B737-300 WHEN HE HIT THE WAKE OF A COMPANY B727-200. HE SAW THE B727 AHEAD OF HIM AND ALTHOUGH THE CTLR HAD URGED HIM TO KEEP HIS SPD UP HE DECIDED TO SLOW WHILE DSNDING AND HE ESTIMATED HIS DISTANCE AT 4.5 NM BASED ON HIS TCASII DISPLAY WHEN HE HIT THE WAKE. DURING THE INITIAL ROLL; THE AUTOPLT WAS ENGAGED AND THE FO ALLOWED IT TO ATTEMPT A RECOVERY. HOWEVER; WHEN THE AUTOPLT ROLLED BEYOND THE WINGS LEVEL POS DURING THE RECOVERY; THE FO DISCONNECTED IT AND CONTINUED THE APCH MANUALLY.