Commercial Fixed Wing
Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine; Flight Crew Instrument
Flight Crew Last 90 Days 48; Flight Crew Total 10682; Flight Crew Type 3741
Communication Breakdown; Distraction; Human-Machine Interface; Situational Awareness
Deviation - Speed All Types; Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural FAR
Air Traffic Control Provided Assistance; Flight Crew Returned To Clearance
Environment - Non Weather Related; Procedure; Human Factors
We exceeded 250 knots below 10;000 and were on speed by 9;600. I (PM) was looking at weather and the STAR and when I went to monitor the aircraft displays I noticed we were doing 300 knots at about 9;760 feet. I said check speed and the PF disengaged the autopilot; reduced power; deployed speed brakes; and leveled off. He had the speed window open and we both failed to monitor the speed window. He is very good about VVM (Verbalize; Verify; Monitor) and not doing something without informing the PM; so I feel I'm just as much responsible for the incident. I believe the speed window was open from a previous instruction from a Controller.
On the ZZZZZX south of ZZZZZ [Intersection]; we exceeded 250 knots below 10;000 feet.ATC had originally asked us to cross ZZZZZ at 15;000 feet leaving us high for the next restriction (ZZZZZ1 at 8;000 feet and 250 knots). I was using speed intervene (300 knots) and flight spoilers to make the anticipated restrictions at ZZZZZ1 while descending from 15;000 feet. The FMA switched from VNAV SPD to VNAV PATH at approximately 12;500 feet. At this point; I began focusing more attention on small build-ups and ensuring the flight attendants were seated. Upon crossing 10;000 feet; the PM called out 'speed' and we quickly corrected to 250 knots by 9;650 feet. ATC passed us off to Approach without commenting about the speed deviation.The FO did a great job as the PM. However; we did debrief that; despite verbalizing the use of speed intervene; we ended up below 10;000 feet above 250 knots. The error is mine and I own that; but recency of experience may have been contributory as well.
Air carrier flight crew reported a speed violation below 10;000 feet.