Narrative:

We were flying to msp at our filed altitude of 14;000 feet; we were instructed to descend via the MUSCL2 RNAV arrival. We plugged in a 3 degree glideslope and verified that if we maintained 3 degrees we would make all crossing restrictions and arrive at our hard limit of 8;000 feet and 230 kts at cmmoe. We briefed that we would descend at the 3 degree slope. The first officer was pilot flying and began his descent via the arrival. ATC then informed us that we had VFR traffic unverified at our 12 o'clock position and that he wanted us to level off at 10;000 feet. We dialed in 10;000 feet and leveled off at 10;000 feet. After a short time ATC instructed us that the traffic was no longer a factor. I asked the controller if he would like us to resume to 'descend via the arrival' and he said yes. The first officer then dialed in 8;000 feet into the altitude selector and called for the approach checklist. I performed the approach check flow and verified completion with the checklist. It was at this point that I noticed the first officer had initiated his descent to 8;000 feet prior to crossing wdbry at 10;000 feet and 250 kts. I called out 'altitude and that we should be at 10;000 feet still'. The first officer kind of froze so I quick hit the altitude button on the mode control panel so the plane would level off. I'm not 100 percent sure but I believe I hit the altitude button at about 9;600-9;700 feet and the plane descended as low as 9;500 feet before slightly climbing back to 9;700 ft. At this point we were very close to wdbry and did not have time to climb back up to 10;000 before crossing so we held level at 9;700 feet as we crossed. We then descended to cross cmmoe at 8;000 feet and 230 kts per the arrival. The rest of the flight was uneventful. After landing and parking at the gate we debriefed what happened; what the contributing factors were; and how to prevent the re-occurrence. I believe that the first officer fully intended to meet all crossing restrictions properly. He just focused on making sure he crossed cmmoe at 8;000 and 230 kts that he forgot that he had to cross wdbry at 10;000 feet. Fortunately the position that the descent was initiated was just prior to the crossing fix so that the deviation was minor and corrected fairly quickly and didn't create any traffic conflicts.I think the contributing factors were 1. Low familiarity and comfort level in the aircraft slightly decreasing situational positional awareness. (First officer has only been on the line a couple months).2. Low familiarity with descend via arrivals.3. Being taken off the descend via clearance due to traffic and then being told to resume got the pilot flying a little out of sequence. 4. Event occurred at a time that I (pilot monitoring) was performing an approach flow and checklist.5. During the debrief we discussed 'descend via' procedures and techniques and I feel that maybe the first officer didn't have a completely solid understanding of techniques and procedures to help ensure and safeguard that all crossing restrictions are met accurately. I feel like 'descend via the arrival' procedures have been an area that some pilots are struggling with and it is common to see a vast array of techniques that are used; (some successfully and some that are not) unfortunately it is common that the pilot monitoring may be distracted with checklists or preparing for the approach; especially if there was a runway change; during this period of heightened workload. During the debrief and discussion of the event with the first officer I feel like we covered the event quite thoroughly and cleared up any confusion that might have been present.

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Original NASA ASRS Text

Title: CRJ-200 reports missing a crossing restriction at WDBRY on the MUSCL2 arrival to MSP.

Narrative: We were flying to MSP at our filed altitude of 14;000 feet; we were instructed to descend via the MUSCL2 RNAV arrival. We plugged in a 3 degree glideslope and verified that if we maintained 3 degrees we would make all crossing restrictions and arrive at our HARD limit of 8;000 feet and 230 kts at CMMOE. We briefed that we would descend at the 3 degree slope. The first officer was pilot flying and began his descent via the arrival. ATC then informed us that we had VFR traffic unverified at our 12 o'clock position and that he wanted us to level off at 10;000 feet. We dialed in 10;000 feet and leveled off at 10;000 feet. After a short time ATC instructed us that the traffic was no longer a factor. I asked the controller if he would like us to resume to 'descend via the arrival' and he said yes. The first officer then dialed in 8;000 feet into the altitude selector and called for the approach checklist. I performed the approach check flow and verified completion with the checklist. It was at this point that I noticed the First Officer had initiated his descent to 8;000 feet prior to crossing WDBRY at 10;000 feet and 250 kts. I called out 'altitude and that we should be at 10;000 feet still'. The first officer kind of froze so I quick hit the ALT button on the mode control panel so the plane would level off. I'm not 100 percent sure but I believe I hit the ALT button at about 9;600-9;700 feet and the plane descended as low as 9;500 feet before slightly climbing back to 9;700 ft. At this point we were very close to WDBRY and did not have time to climb back up to 10;000 before crossing so we held level at 9;700 feet as we crossed. We then descended to cross CMMOE at 8;000 feet and 230 kts per the arrival. The rest of the flight was uneventful. After landing and parking at the gate we debriefed what happened; what the contributing factors were; and how to prevent the re-occurrence. I believe that the First officer fully intended to meet all crossing restrictions properly. He just focused on making sure he crossed CMMOE at 8;000 and 230 kts that he forgot that he had to cross WDBRY at 10;000 feet. Fortunately the position that the descent was initiated was just prior to the crossing fix so that the deviation was minor and corrected fairly quickly and didn't create any traffic conflicts.I think the contributing factors were 1. Low familiarity and comfort level in the aircraft slightly decreasing situational positional awareness. (First Officer has only been on the line a couple months).2. Low familiarity with descend via arrivals.3. Being taken off the descend via clearance due to traffic and then being told to resume got the pilot flying a little out of sequence. 4. Event occurred at a time that I (pilot monitoring) was performing an approach flow and checklist.5. during the debrief we discussed 'descend via' procedures and techniques and I feel that maybe the First Officer didn't have a completely solid understanding of techniques and procedures to help ensure and safeguard that all crossing restrictions are met accurately. I feel like 'descend via the arrival' procedures have been an area that some pilots are struggling with and it is common to see a vast array of techniques that are used; (some successfully and some that are not) unfortunately it is common that the pilot monitoring may be distracted with checklists or preparing for the approach; especially if there was a runway change; during this period of heightened workload. During the debrief and discussion of the event with the First Officer I feel like we covered the event quite thoroughly and cleared up any confusion that might have been present.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.