Flight Crew Multiengine; Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument
Situational Awareness
Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter CFTT / CFIT
Flight Crew Became Reoriented; Flight Crew FLC Overrode Automation
Aircraft; Company Policy; Environment - Non Weather Related
On a straight in visual approach to Runway 31 in BIS; we received a gear horn aural. We were not yet fully configured but did notice we were 4 or 5 miles from the runway. We immediately configured the aircraft to full configuration. I noticed then that the radar altimeter was roughly 880 feet while we were still a few miles from the runway. I was aware of the terrain surrounding the southeast side of the airport and knew it was higher than at the airport and felt we were still in a safe condition and safe altitude above field elevation to land. We continued the approach; kept it stabilized and safely landed the aircraft in the touchdown zone on centerline.The primary cause was a combination of a slight loss of situational awareness as well as the differing terrain in the environment. We had discussed the terrain on the approach briefing; and as always would have the aircraft stabilized to meet the stabilized criteria. One primary factor that caused me to configure late was the failure of the FMS to sequence to the final segment. I believed we were 6 miles (from FMS info) from the airport when we actually about 4. The terrain in the area is slightly higher than that at the field so our radar altimeters sensed we were too low to not be fully configured. Typically hearing the gear horn would cause me to go around but we felt we were at a safe altitude above field elevation and as well as distance from the field. I should have briefed that this was a threat because I had encountered it before. I failed to have a proper mitigation tactic; such as configuring earlier than normal to avoid startling either pilot. I also failed to realize the FMS did not sequence properly and was giving us false information on our distance from the runway. A go-around could have been executed; but as stated earlier; both pilots felt we were still at a safe distance and altitude to become fully configured and safely continue the approach.
CRJ200 Captain reported gear horn warning due to passing higher terrain on visual approach.