Small Aircraft; Low Wing; 1 Eng; Fixed Gear
Flight Crew Commercial; Flight Crew Multiengine; Flight Crew Instrument
Flight Crew Last 90 Days 75; Flight Crew Total 1700; Flight Crew Type 900
Situational Awareness; Human-Machine Interface
Aircraft Equipment Problem Less Severe; Deviation - Altitude Overshoot; Deviation - Altitude Crossing Restriction Not Met; Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural Clearance; Inflight Event / Encounter CFTT / CFIT
Flight Crew Overcame Equipment Problem
Environment - Non Weather Related; Airport; Aircraft; ATC Equipment / Nav Facility / Buildings
On vectors from Houston Approach for the ILS 14 at GLS. Cleared to intercept the localizer from current heading maintain 2;000 feet. Tracking the localizer inbound at 2;000 feet was given a handoff to Tower. I wasn't cleared for the approach so I asked if I was cleared ILS. Was given clearance and switched to GLS Tower.The glideslope needle went active and I lowered the gear to follow the glide slope down. 400 feet later the glide slope needle flagged out and came in and out. I initiated a climb and realized I was outside of the final approach fix. This was a false glideslope.I climbed back to 1;800 feet and approached the FAF. The real glideslope came in and I completed the approach.I reported the issue via telephone to the Tower after landing.The late clearance from Center for the approach [was a contributing factor]. I didn't brief myself clearly enough on the minimum altitudes until the FAF. I had a big headwind so my internal timer felt right to be descending but the reduced ground speed I was still outside of the FAF.My reaction to realizing the issue was fast. I stopped my descent and started a climb quickly upon seeing the glideslope problems. I then identified the problem and what happened. Resumed the approach when everything was correct.
Pilot reported glideslope problems while inbound to GLS airport.