Narrative:

Low altitude alert by ATC. GS (glide slope) was stuck centered. While flying a normal IFR approach using a flight director; the approach was proceeding normally on profile; received a low altitude alert; compared left to right; and went missed. The GS on the left side HSI and FD (flight director) stayed frozen in the center during the climb. The GS returned to normal operation when the lights were turned off as part of the cleanup on the climb. First officer said he was about make a call about a disagreement with his GS to mine. ATC stated they had GS equipment issues the day before; and wanted to know the outcome of us tuning in the vs/ILS in ZZZ after the VFR landing.apparently an equipment failure; either with the GS or receiver.compared GS indication; went missed; diversion to ZZZ to land VMC; tested GS on a VMC approach; nothing abnormal noted.a repeater navigation#2 with a GS like on many planes; visible from the left side would allowed the captain to compare GS on the approach. Had this occurred without a copilot or at an uncontrolled airport; the result would have been a crash with no GPWS (ground proximity warning system). The fact that the local VOR/DME has been removed from service greatly limits your ability to fix you position when the flying the approach without a GPS.

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Original NASA ASRS Text

Title: Light Transport flight crew reported a glideslope failure on approach to ELM airport that resulted in a diversion.

Narrative: Low altitude alert by ATC. GS (Glide Slope) was stuck centered. While flying a normal IFR approach using a flight director; the approach was proceeding normally on profile; received a low altitude alert; compared left to right; and went missed. The GS on the left side HSI and FD (Flight Director) stayed frozen in the center during the climb. The GS returned to normal operation when the lights were turned off as part of the cleanup on the climb. First Officer said he was about make a call about a disagreement with his GS to mine. ATC stated they had GS equipment issues the day before; and wanted to know the outcome of us tuning in the VS/ILS in ZZZ after the VFR landing.Apparently an equipment failure; either with the GS or receiver.Compared GS indication; went missed; Diversion to ZZZ to land VMC; tested GS on a VMC approach; nothing abnormal noted.A repeater NAV#2 with a GS like on many planes; visible from the left side would allowed the Captain to compare GS on the approach. Had this occurred without a Copilot or at an uncontrolled airport; the result would have been a crash with no GPWS (Ground Proximity Warning System). The fact that the local VOR/DME has been removed from service greatly limits your ability to fix you position when the flying the approach without a GPS.

Data retrieved from NASA's ASRS site 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.