AN EMB120 FO INADVERTENTLY FLIES THROUGH THE LOC OF ILS RWY 9 AT IAH; TX.

Narrative

WE WERE SUPPOSED TO BE ON THE GLAND 8 ARR AND WERE TOLD TO EXPECT ILS RWY 9. WE WERE DEVIATING N OF THE HUMBLE 234 DEG RADIAL DUE TO TSTMS. WE WERE CLRED FOR THE ILS RWY 9. THE FO WAS FLYING. ATC GAVE US A 060 DEG HDG (I BELIEVE) TO INTERCEPT THE LOC. I POSITIVELY IDENTED THE LOC FREQ ON BOTH NAVS AND THE INBOUND COURSE ON BOTH SIDES. I NOTICED THE LOC NEEDLE COMING ALIVE AND CALLED IT AND THE FO ACKNOWLEDGED. I THEN WENT OFF OF COM #1 TO TELL THE FLT ATTENDANT TO BE SEATED FOR LNDG. WHEN I GOT BACK ON COM #1; WE WERE FULL SCALE DEFLECTION TO THE N OF THE LOC COURSE. ATC THEN ASKED US IF WE WERE FOLLOWING THE LOC FOR RWY 8 AND NOT FOR RWY 9. I TOLD HIM THAT WE DID HAVE THE LOC FOR RWY 9 TUNED IN THE NAV. ATC THEN GAVE US A 110 DEG HDG TO REINTERCEPT THE LOC. THE FO AT THIS TIME TOLD ME THAT HE HAD THE WRONG INBOUND COURSE ON HIS EHSI AND THAT WAS WHY HE FLEW THROUGH THE LOC. ONCE WE WERE BACK ON THE LOC; WE WERE TOLD TO CONTACT TWR AND LANDED WITHOUT ANY OTHER PROBS. AS A CAPT; I SHOULD HAVE BEEN MORE AWARE OF US FLYING THROUGH THE LOC INSTEAD OF NOTIFYING THE FLT ATTENDANT TO BE SEATED. I ALSO SHOULD HAVE XCHKED THE FO'S INBOUND COURSE ON HIS EHSI DURING THE APCH CHKLIST. FROM NOW ON; I WILL BRIEF THE FO TO ENSURE THAT BOTH OF US DO INDEED HAVE THE CORRECT INBOUND COURSE ON EACH OF OUR EHSI'S.