Date: 201807
Local time of day: 1201-1800
Location: LSE.Airport, WI
Flight conditions: VMC
Light: Dusk
Aircraft: Regional Jet CL65; Undifferentiated or Other Model
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Final Approach
Airspace: Class D LSE
ATC / advisory: Tower LSE
Reporter organization: Air Carrier
Reporter function: First Officer; Pilot Flying
Reporter qualification: Flight Crew Multiengine; Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument
Human factors: Communication Breakdown; Situational Awareness
Second reporter function: Pilot Not Flying; Captain
Anomaly: Deviation - Speed All Types; Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter CFTT / CFIT
Detector: Automation Aircraft Terrain Warning
When detected: In-flight
Result: Flight Crew Took Evasive Action; Flight Crew Became Reoriented
Contributing factors: Human Factors
Primary problem: Human Factors

Narrative: Cleared visual with GPS FMS backup. Vectored in for visual; not on intercept course to GPS straight in. Captain had airport in sight; I did not but knew general area of field (referenced Jeppesen graphic and noted field location in reference to major landmarks). As a crew we called field in sight. I began descent based on mental calculation; mistakenly assuming Captain was visually backing up me with regards to runway alignment and visual descent point. Captain assumed I had a plan and situational awareness of runway. [Received] GPWS (Ground Proximity Warning System) terrain message; Captain momentarily took controls; momentary stick shaker. Corrected flight path and normal approach and landing.Vertical guidance not set correctly. Communication breakdown. Failure to verify vertical guidance. Unfamiliar with airport at dusk. Never assume anything. Never assume in aviation. Never call field in sight unless pilot flying sees it.


Second narrative: Cleared for the visual approach. Also had the GPS approach in the FMS (Flight Management System) to back it up since it was dusk. Captain had airport and runway in sight. Assumed FO (First Officer) did as well. FO was flying and commenced the visual and started descending but was not on the course. Captain assumed FO knew what he was doing and making a tighter approach since FO was more familiar with the airport. Captain noticed proximity to terrain but terrain aural went off before Captain spoke up. Captain instructed FO to level off but the altitude kept decreasing. Captain took over and was too aggressive with the controls which caused a momentary stick shaker. Corrective action was taken. Aircraft returned to altitude and course and a stabilized; normal landing was made.Captain made erroneous assumptions based on FO previous experience. Captain should have instructed the FO to make a more square base to allow for a more conservative approach. Box was not set up to aid in approach (VNAV guidance snowflake). There was no shared mental model.As a crew we should be saying the plan aloud to ensure a shared mental model. If unsure of anything; airport location; course; plan; just ask and never assume. Ensure the box has been properly set up (VNAV snowflake) to aid in approach. Even though the approach was shot at dusk; being on the approach and briefing it as to shoot it at night would be much advised.


Synopsis: CRJ flight crew reported receiving a terrain warning on a dusk visual approach to LSE.