AN ACR LGT; ALONG WITH SOME OTHER NON-RPTING ACFT; SUFFERED ILS FAILURE INDICATIONS TO SGF IN THE WX. SEVERAL GARS HAD TO BE PERFORMED.

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RWY 2 ILS AT SGF; MO; FO FLYING USING AUTOPLT COUPLED TO ILS. AT APPROX 800 FT AGL; I NOTICED GPWS FAIL LIGHT ILLUMINATE; FOLLOWED IMMEDIATELY BY LOC AND GS OFF FLAGS; AND FLT DIRECTOR COMMAND BARS BIASING OUT OF VIEW. THIS CONDITION LASTED A VERY SHORT TIME; (LESS THAN 2 SECONDS) UNTIL ALL INSTS RETURNED TO NORMAL. AUTOPLT REMAINED ENGAGED. BTWN 400 FT AGL AND 300 FT AGL; THE ABOVE CONDITION REPEATED ITSELF; EXCEPT AT THIS TIME; THE LOC AND GS OFF FLAGS REMAINED IN VIEW. WE EXECUTED THE PUBLISHED MISSED APCH. IN THE NEXT 10-15 MINS; 2 OTHER ACFT ATTEMPTED THIS SAME APCH; AND RPTED INST FAILURE AT OR NEAR DECISION HT. AT LEAST 1 OTHER ACFT BEHIND US ATTEMPTED AND COMPETED THE APCH WITH NO RPTED PROB. ON OUR SECOND APCH; INSTRUMENTATION WAS NORMAL; BUT WX WAS NOT ADEQUATE FOR LNDG. ON OUR THIRD APCH; INSTRUMENTATION WAS AGAIN OK. WE SAW THE RWY AT DECISION HT AND LANDED. THROUGHOUT THIS TIME FRAME; I QUERIED THE CTLR SEVERAL TIMES AS TO THE CONDITION OF THE ILS XMITTER. HIS REPLY WAS 'I HAVE 2 GREEN LIGHTS; NO PROB INDICATED; EVERYTHING LOOKS OK HERE' ETC; ETC.