THE ACR FLC ON A BA32 LOST SIGHT OF THEIR PRECEDING TFC DURING A NIGHT VISUAL APCH AND THE CTLR SENT THEM AROUND. THE FLC BLAMES FATIGUE AND BACKGND LIGHTS.

Narrative

ON VISUAL APCH TO STL RWY 12R MAINTAINING VISUAL WITH PRECEDING TFC AND LATERAL TFC TO RWY 12L; S TWR CHANGED APCH CLRNC TO RWY 12L WITHOUT ASKING IF WE COULD FOLLOW PRECEDING ACFT. ON VISUAL TO RWY 12L; N TWR ASKED IF WE COULD ACCEPT RWY 13. WE DECLINED DUE TO XWIND; LACK OF GS GUIDANCE; NIGHT CREW FATIGUE; RWY LENGTH; AND WIDTH. TWR THEN ASKED IF WE COULD FOLLOW/SEE THE COMPANY ACFT 3 1/2 MI AHEAD. AT THIS TIME; WE HAD LOST THAT TFC (FORMERLY IN SIGHT AS LATERAL TFC) IN GND CLUTTER/CITY LIGHTS. TWR HAD US GAR AT THAT TIME. NO KNOWN CONFLICTS OCCURRED OR EXISTED (TO FLC). HUMAN FACTORS CONTRIBUTING WERE CREW ON 8 HR SCHEDULED REDUCED REST OVERNIGHT; FOLLOWED BY XA45 WAKE-UP; 7 LEGS TERMINATING WITH A 3 HR ROUND TRIP ENDING AT NIGHT (7 1/2 HRS FLYING TOTAL). THIS ALSO CONTRIBUTED TO CREW FLYING WRONG HDG (330 DEGS) INSTEAD OF 360 DEGS ON DEP FROM FSM WHEN CLRED ON COURSE DIRECT SGF VOR WHEN NOT RECEIVING. THESE ARE 2 EVENTS DIRECTLY RELATED TO LACK OF CREW REST AND UNREASONABLE SCHEDULES.