A B727 FLT CREW INADVERTENTLY LWOC AT HOU AFTER BECOMING DISTR.

Narrative

A B727-200 LANDED AT HOUSTON GEORGE BUSH (IAH) WITHOUT OBTAINING A LNDG CLRNC FROM IAH TWR. THE LEADING CAUSE WAS PLT ERROR DUE TO PLT FATIGUE. OTHER CONTRIBUTING FACTORS ARE IN ORDER OF IMPORTANCE: 1) WX: FOG 1/2 MI VISIBILITY. RVR FOR RWY 26L WAS 4500 FT AT TOUCHDOWN AND 6000 FT RVR AT MID AND ROLLOUT. A MONITORED APCH WAS FLOWN AS PER ASTAR AIR CARGO GOM RULES. 2) ATC CHANGED THE RWY FROM RWY 8R TO RWY 26L AFTER THE CREW HAD BRIEFED THE RWY 8R APCH. THIS REQUIRED THE CREW TO BRIEF THE NEW APCH. ATIS WAS STATING THAT RWY 8R AND RWY 8L APCHS WERE IN USE. 3) DUE TO THE RWY SWITCH THE CREW WAS LATE TO CALL FOR THE BEFORE LNDG CHKLIST. LOC NEEDS TO BE TUNED AND IDENTED BEFORE THE CHKLIST CAN BE CALLED FOR. 4) THE FLT CREW WAS LATE CONFIGURING THE ACFT TO THE LNDG CONFIGN DUE TO A QUICK SHORT VECTOR FROM ATC TO THE FINAL APCH COURSE. WHEN CLRED FOR THE APCH AND THEN INSTRUCTED TO CONTACT HOUSTON TWR ON 127.3; THE CREW WAS BUSY CONFIGURING THE ACFT FOR LNDG. THIS DISTR THE PNF; IE; THE CAPT FROM TUNING IN THE CORRECT FREQ OF 127.3. 127.7 WAS TUNED. THE FO WAS FLYING AND CONCENTRATING ON GETTING THE ACFT PROPERLY CONFIGURED ALONG WITH SETTING UP THE AUTOPLT AND FLT DIRECTOR FOR THE MONITORED APCH. 5) THE OM BEACON DID NOT SOUND OFF. IF THE PF HAD HEARD THE MARKER BEACON SOUND; HE WOULD HAVE STATED 'START TIME; CALL TWR AND REVIEW THE MISSED APCH.'