A B757-200 DSNDING ON APCH AT 2700 FT EXECUTED A MISSED APCH DUE TO A TRAILING EDGE SPLIT FLAP INDICATION CAUSED BY A FAILED INDICATOR.

Narrative

WE HAD BEEN CLRED FOR A VOR DME APCH TO RWY 30L AT SAN JOSE; CA. THE ILS; LOC AND GS WERE NOTAMED OTS. WE WERE BTWN THE IAF AND FAF DSNDING FROM 2700 FT TO THE FAF ALT OF 1700 FT. WE WERE IMC WITH A 1000 FT VARIABLE; 1500 FT CEILING; VISIBILITY 3-5 MI. WE PLACED THE LNDG GEAR DOWN; THE FLAPS TO 30 DEGS FROM 20 DEGS; AND STARTED THE BEFORE LNDG CHKLIST. AS WE APCHED THE FAF; WE OBSERVED THE FLAP NEEDLES (SPECIFICALLY ONE SIDE) INDICATED THOSE WING FLAPS WERE AT 30 DEGS AND THE OTHER SIDE INDICATED 20 DEGS. I WAS FLYING THE ACFT ON AUTOPLT AND IMMEDIATELY HIT ALT HOLD PASSING THE FAF. THE COPLT CALLED MISSED APCH TO THE TWR AND WE WERE GIVEN RWY HDG 3000 FT. I SELECTED TOGA PWR ON THE AUTOTHROTTLES AND AS THE ACFT BEGAN THE MISSED APCH; I INSTRUCTED THE COPLT TO REF THE ABNORMAL PROC FOR FLAPS TRAILING EDGE FLAP ASYMMETRY. THE ONLY INDICATION OF AN ASYMMETRY WAS THE SPLIT FLAP NEEDLES. WE DID NOT HAVE A TRAILING EDGE FLAP LIGHT NOR A FLAP ASYMMETRY STATUS MESSAGE NOR DID WE HAVE ANY ABNORMAL; TRIM OR AUTOPLT INPUTS. AFTER REFING THE PROC IN THE ABNORMALS POM; WE VALIDATED THAT OUR ASYMMETRY INDICATION WAS ONLY FROM A MALFUNCTIONING GAUGE AND THE FLAPS WERE WORKING NORMALLY. WE RETRACTED THE FLAPS TO 20 DEGS AND RAISED THE GEAR. WE INFORMED THE TWR THAT WE THOUGHT WE HAD A MALFUNCTIONING FLAP GAUGE AND WE REQUESTED VECTORS FOR A DOWNWIND TO TROUBLESHOOT AND PREPARE FOR ANOTHER APCH. WE WERE VECTORED FOR A 4000 FT MSL DOWNWIND AND ONCE AGAIN LOWERED THE GEAR. WE PLACED THE FLAP HANDLE FROM 20 DEGS TO 25 DEGS. INITIALLY; 1 NEEDLE REMAINED AT 20 DEGS AND 1 WENT TO 25 DEGS. AFTER A COUPLE OF SECONDS; THE SECOND NEEDLE WENT TO 25 DEGS. NO ABNORMAL. INDICATIONS OR CTL INPUTS WERE OBSERVED. THE FLAPS WERE LOWERED TO 30 DEGS AND A BEFORE LNDG CHK AND ANOTHER APCH CHK WERE ACCOMPLISHED. WE EXECUTED A NORMAL APCH AT THIS TIME AND MADE AN UNEVENTFUL LNDG.