Regional Jet 200 ER/LR (CRJ200)
Flight Crew Air Transport Pilot (ATP)
Confusion; Situational Awareness; Training / Qualification
Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter Unstabilized Approach
Flight Crew Became Reoriented; Flight Crew Took Evasive Action
Chart Or Publication; Human Factors; Procedure
I was pilot flying during the given date and time. While descending into the terminal area we were cleared down to 3;000 feet. Around 10NM away from the airport we were cleared for the visual approach to 36R. At 10NM I realized I was still doing 250 knots and needed to slow down quickly in order to have a stable approach by 1;000 feet AGL. I deployed full spoilers and slowed to 220 knots. The glideslope was captured and in order to keep a fast rate of deceleration going I called for gear down at 220 knots. Once at 200 knots I called for Flaps 8. I intentionally left the spoilers out to continue to help with decelerating. I called for Flaps 20 at around 190 knots and Flaps 30 at 180.  At 160 knots we were approximately 1;300-1;500 feet and called for Flaps 45 and bugged Vref of 139 for the landing. As we slowed to about 145 knots I was just about to put the spoilers back down when all of the sudden the plane automatically disengaged the autopilot and the stick shaker went off for 1 sec. Our speed was never below Vref of 139 and as soon as the spoilers were retracted the shaker stopped and NO INCREASE in power was necessary to remain stable. To my knowledge the continuous ignition did not engage either. Both my First Officer (FO) and I tried to understand why we had momentarily experienced a shaker when; in our opinion and experience; we should not have. The rest of the landing and following leg back was uneventful.After further thought; I believe the shaker went off possibly due to my spoilers intentionally out to slow down; the airspeed trend vector quite possibly had gone too far into the bottom barber pole possibly causing the auto pilot and shaker to go off for a split second... Again my airspeed was never in danger of falling below Vref or into the barber pole... I should have definitely retracted my spoilers much sooner in order to avoid the situation. But at no time to did I not realize the spoilers were out and again at no time did my speed fall below Vref.
A CRJ-200 stick shaker activated momentarily and the autopilot self-disconnected while descending for landing near 1;000 feet; with the speed brakes extended; flaps 45; and at 145kts.