Flight Crew Multiengine; Flight Crew Flight Instructor; Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 30; Flight Crew Total 14000; Flight Crew Type 2000
Situational Awareness
Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter CFTT / CFIT
Flight Crew Took Evasive Action; Flight Crew Became Reoriented
Human Factors
We were on an IFR flight plan; on a visual approach to runway 34; on a wide left base to final. I was using the ILS as a backup to the visual approach. I inappropriately armed the approach mode instead of the localizer mode; and when the glide slope needle started descending; I followed the flight director commands to descend.My copilot protested that something was wrong; and that I should not be descending any lower considering we were now at 800 feet AGL while still 5 miles from the runway. Immediately thereafter the control tower called and asked about our altitude.I immediately climbed back up to 1;500 feet AGL.We did not receive a Traffic Alert Warning System (TAWS) alert.After landing we discussed that the flight director must have captured a false glide slope; and that I should not have armed the approach mode before being established on the localizer.I believe that a contributing factor was complacency due to the visual conditions.
[Report narrative contained no additional information]
FA10 flight crew reported descending to 800 feet AGL on a visual approach to FTW when the pilot flying followed a false glideslope.