Narrative:

We had been cleared for a VOR DME approach to runway 30L at san jose, ca. The ILS, localizer and GS were notamed OTS. We were between the IAF and FAF descending from 2700 ft to the FAF altitude of 1700 ft. We were IMC with a 1000 ft variable, 1500 ft ceiling, visibility 3-5 mi. We placed the landing gear down, the flaps to 30 degrees from 20 degrees, and started the before landing checklist. As we approached the FAF, we observed the flap needles (specifically one side) indicated those wing flaps were at 30 degrees and the other side indicated 20 degrees. I was flying the aircraft on autoplt and immediately hit altitude hold passing the FAF. The copilot called missed approach to the tower and we were given runway heading 3000 ft. I selected toga power on the autothrottles and as the aircraft began the missed approach, I instructed the copilot to reference the abnormal procedure 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 referencing the procedure 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 degrees and raised the gear. We informed the tower that we thought we had a malfunctioning flap gauge and we requested vectors for a downwind to troubleshoot and prepare for another approach. We were vectored for a 4000 ft MSL downwind and once again lowered the gear. We placed the flap handle from 20 degrees to 25 degrees. Initially, 1 needle remained at 20 degrees and 1 went to 25 degrees. After a couple of seconds, the second needle went to 25 degrees. No abnormal. Indications or control inputs were observed. The flaps were lowered to 30 degrees and a before landing check and another approach check were accomplished. We executed a normal approach at this time and made an uneventful landing.

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Original NASA ASRS Text

Title: 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.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.