Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine
Flight Crew Last 90 Days 75; Flight Crew Type 75
Distraction; Situational Awareness
Deviation - Altitude Crossing Restriction Not Met; Deviation - Altitude Overshoot; Deviation - Speed All Types; Deviation / Discrepancy - Procedural Clearance; Inflight Event / Encounter Wake Vortex Encounter
Air Traffic Control Issued New Clearance; Flight Crew Became Reoriented
Aircraft; Human Factors
On a descent into DEN; we were cleared to descend via the CLASH 3 Arrival. I confirmed that the final altitude was 9;000 ft. and selected it in the altitude window. About 10 miles from EVRLY; we experienced wake turbulence for about five seconds; and then experienced it again. I selected Vertical Speed and leveled off the descent to get above the wake turbulence. After we were clear of the wake turbulence; I selected a 2;000 FPM descent to get back on my vertical path. At that time; we were told to switch to Denver Approach. Upon checking in with Denver Approach they changed our runway to 35L. At this point I was concerned about changing the approach in the FMC. I forgot to re-engage the VNAV. Because I forgot to re-engage the VNAV; the aircraft did not slow down to 250 kts for EVRLY. The aircraft also continued a descent below 12;000 feet.; which was the lowest altitude at TWNSN. The aircraft continue to descend until I notice the deviation. By this time I was leveling at 10;000 feet. and was below the 11;000 feet. altitude required for PNBAL. ATC advised me to slow the 210 knots; and gave me a vector for the final approach to Runway 35L. They also gave me a descent to 9;000 feet. The rest of the arrival went as planned.
B737 Captain reported distractions from a wake turbulence encounter on arrival into DEN contributed to altitude and speed deviations.