We were on approach into an airport in Columbia at about 6000 feet agl. Slight tailwind the PIC kept pulling back the throttle trying to maintain a particular ground speed for the approach. I was calling out the airspeeds as we got slower and slower, my anxiety was increasing, the copilot and I kept looking at the PIC wondering wtf? When everything suddenly got quiet as the wind direction changed. The aircraft started to shudder, the stick shaker went off, and we started to fall as both I and the copilot fire walled the throttles. We recovered about 1500 feet above the ground, scooted in just over the trees to land. Dead silence in the cockpit. We had a crew meeting out in front of the jet. Called home and they sent another pilot out to us. That pilot never flew again. Scary shit!