Narrative:

Approaching sat from the north, we were cleared for the visual approach for runway 12R. The controller cleared us for the visual. At about 6 mi from the airport, the PNF (captain) set the localizer frequency for runway 12R on #1 VOR/ILS and idented the station, then reached forward to tune the ADF frequency. The PF (first officer) started down to the full fly down GS needle. He left 3000 ft and was descending when we all noticed we were too low, even with the full fly down needle. It took several seconds to realize we were trying to intercept a false GS (we were too far to the north of the localizer to receive a valid signal). We climbed back to a good visual glide path then turned final and followed the GS to a landing. It is likely that we operated below the electronic GS on a visual approach where one was available. To cure this, better cockpit discipline is needed. I should have not have been tuning radios so close to the airport. Supplemental information from acn 458719: on visual approach for sat runway 12R on base. Approximately 4-6 mi out, the first officer (flying) descended lower than normal due to false GS. My focus was on flight engineer duties. I was looking for the airport when the captain called too low and the first officer quickly recovered to 1500 ft AGL.

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Original NASA ASRS Text

Title: B727 CREW DSNDS TOWARD TERRAIN ON FALSE GS ON VISUAL APCH TO SAT.

Narrative: APCHING SAT FROM THE N, WE WERE CLRED FOR THE VISUAL APCH FOR RWY 12R. THE CTLR CLRED US FOR THE VISUAL. AT ABOUT 6 MI FROM THE ARPT, THE PNF (CAPT) SET THE LOC FREQ FOR RWY 12R ON #1 VOR/ILS AND IDENTED THE STATION, THEN REACHED FORWARD TO TUNE THE ADF FREQ. THE PF (FO) STARTED DOWN TO THE FULL FLY DOWN GS NEEDLE. HE LEFT 3000 FT AND WAS DSNDING WHEN WE ALL NOTICED WE WERE TOO LOW, EVEN WITH THE FULL FLY DOWN NEEDLE. IT TOOK SEVERAL SECONDS TO REALIZE WE WERE TRYING TO INTERCEPT A FALSE GS (WE WERE TOO FAR TO THE N OF THE LOC TO RECEIVE A VALID SIGNAL). WE CLBED BACK TO A GOOD VISUAL GLIDE PATH THEN TURNED FINAL AND FOLLOWED THE GS TO A LNDG. IT IS LIKELY THAT WE OPERATED BELOW THE ELECTRONIC GS ON A VISUAL APCH WHERE ONE WAS AVAILABLE. TO CURE THIS, BETTER COCKPIT DISCIPLINE IS NEEDED. I SHOULD HAVE NOT HAVE BEEN TUNING RADIOS SO CLOSE TO THE ARPT. SUPPLEMENTAL INFO FROM ACN 458719: ON VISUAL APCH FOR SAT RWY 12R ON BASE. APPROX 4-6 MI OUT, THE FO (FLYING) DSNDED LOWER THAN NORMAL DUE TO FALSE GS. MY FOCUS WAS ON FE DUTIES. I WAS LOOKING FOR THE ARPT WHEN THE CAPT CALLED TOO LOW AND THE FO QUICKLY RECOVERED TO 1500 FT AGL.

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.