Flight Crew Air Transport Pilot (ATP)
Distraction; Human-Machine Interface; Situational Awareness; Workload
Deviation - Altitude Crossing Restriction Not Met; Deviation - Altitude Overshoot; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy
Air Traffic Control Issued Advisory / Alert; Flight Crew Became Reoriented; Flight Crew Returned To Clearance; Flight Crew Took Evasive Action
Human Factors; Procedure
Flight cleared to descend via CHSLY2 RNAV arrival into CLT. Set bottom altitude to 6000 [feet] msg per procedure; Cockpit workload high due to weather in area. Between WHIZE and CAATT intersection I noted speed error at CAATT intersection. As pilot flying; I intervened and selected speed of 210kias and vertical speed in order to correct error; this left aircraft in an un-managed vertical mode with altitude set at bottom altitude (6000). Descent below 9000 occurred prior to CAATT intersection before First Officer trap error at 8800 feet. Aircraft was returned to minimum altitude of 9000 feet simultaneously with call from ATC; whom trapped the error as well. No loss of separation occurred and flight proceeded normally to landing. High workload environment led to not monitoring altitude constraints properly by pilot flying. In addition; full use of automation was 'dropped' in order to intervene with perceived error in FMGS. Due to high work load; pilot flying was task saturated. Fortunately Pilot Monitoring trapped error early enough as to not lose separation. Keep two pilots in cockpit in future in order to trap future errors.
On the CHSLY2 RNAV arrival to CLT; Captain selected open descent after WHIZE and had his hand on the vertical speed knob. I assumed he would push to level off at 9000 to make the restriction at CAATT. When he did not stop the descent I said; 'It should be 9000 at CAATT.' By the time he reacted we were at 8750. We immediately climbed back to 9000 and were already leveling off when ATC asked about our altitude.
Air Carrier flight crew reported becoming distracted during a high workload descent on the CHSLY 2 RNAV into CLT; and descended below the descent profile.