Flight Crew Multiengine; Flight Crew Instrument; Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 181; Flight Crew Type 2236
Situational Awareness
Deviation - Altitude Overshoot; Deviation / Discrepancy - Procedural Clearance; Inflight Event / Encounter CFTT / CFIT; Inflight Event / Encounter Weather / Turbulence
Flight Crew Took Evasive Action; Flight Crew Became Reoriented; Flight Crew Returned To Clearance
Human Factors
We were at FL370 and were directed by ATC to descend now to FL270. As the pilot flying I engaged level change after FL270 was entered in the altitude window. Prior to reaching FL270 ATC gave us 'descend via the KAILE 2 arrival'. I never engaged the VNAV function to ensure altitude protection. Approaching SKARF; ATC gave us a low altitude warning. At this point we realized we had descended below the MSA of 16;000 feet to an altitude of 15;000 feet. We immediately initiated a climb and pushed the throttles full forward. We were able to climb to 17;000 feet prior to SKARF. I had terrain mode up on my displays. We did not receive any EGPWS warnings. Upon reaching 17;000 feet we were notified of possible moderate turbulence on the remainder of the descent. The Captain told the FAs (Flight Attendants) to take their seats due to possible turbulence. As soon as the Captain notified the FAs we encountered the turbulence. It started out at as light to moderate but soon became severe turbulence. The aircraft's autopilot had a hard time maintaining level flight and the lateral control system disengaged reverting the control wheel steering function. I was able to maintain control and eventually engage the LNAV function. The turbulence continued until we were on a segment of the published approach for RWY 16L.
B737 First Officer reported receiving a low altitude alert from ATC after overshooting a target altitude on descent into DEN.