Dash 8 Series Undifferentiated or Other Model
Flight Crew Multiengine; Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument
Communication Breakdown; Situational Awareness; Confusion; Distraction
Deviation - Speed All Types; Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter Weather / Turbulence
Human Factors; Weather
We were coming into ZZZ on the ZZZZZ Arrival. We were a bit high and fast so we had to slow down a bit and loose altitude. On the descent we picked up some ice so I turned the REF speeds [switch] to INCR (increase). As we descended we checked for ice and there was still some on the right wing so I left the REF speeds to INCR. As we were approaching 3;000 ft we were fully configured and about 5 to 10 kts above open bug; which was about 115 to 120. The red line approached but we never exceeded it. When we got the stick shaker the FO (First Officer); who was pilot flying; just lowered the nose a bit to correct. It then stopped and we continued on with the approach and safe landing. At that point I turned the REF speeds to off. I should have done another ice check on descent so we would have turned the REF speeds off.
Operating Aircraft X from ZZZ1 to ZZZ as we began our approach and passed through 10;000 ft. We completed the approach checklist and checked wings for icing. I identified my wing still had icing present so we continued our decent with the ref speeds increased. As we continued our decent we went through our configuration checks and began slowing down. As we continued our decent a few moments later I checked my wing again and identified the icing was no longer present. Before we went through 1000 ft. my speed was set between solid bug and open bug in preparation for the approach; I noticed that the Vso speed was indicating near the open bug speed. I was maintaining approximately 5 knots above the open bug speed when I got a momentary stick shaker; I immediately increased pitch and announced 'stick shaker'. A quick scan to the ED (engine display) and I identified that the ref speeds were still increased and told the Captain; at that time he turned it off. We continued the remainder of the approach without incident. I am filing this report after being notified by Manager of Flight Safety that he recommended an ASAP should be filed. Lesson learned for me as a FO (First Officer) is that I should have verified that the ref speed switch was turned off after verifying that the icing was no longer present. And then again when I noticed the Vso speed was higher than I anticipated; I should have cued in that something wasn't set properly.
Air carrier flight crew flying DHC8 aircraft report Aircraft Limit Speed exceedance on approach.