B737 Next Generation Undifferentiated
Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 182; Flight Crew Type 5500
Deviation - Altitude Excursion From Assigned Altitude; Deviation - Speed All Types; Inflight Event / Encounter Weather / Turbulence
Air Traffic Control Issued New Clearance; Flight Crew Took Evasive Action
Environment - Non Weather Related
At FL410 we were cruising with very light Mountain Wave (MTW) at 52 NM west of Pueblo (PUB) VOR; we then heard (other carrier) request altitude block and deviation for severe mountain wave encounter at FL390; altitude plus or minus 200 feet; airspeed plus or minus 30 knots. The location of encounter was at 45 NM west of Pueblo crossing the Rockies. I did notice very slight variations at FL410; when suddenly this wave hit us (45 NM west of PUB); full strength the airspeed went straight beyond the barber poll 10 knots into VMO/MMO [maximum operating speed]; speed attained was 252 KIAS or Mach .83. I did everything in my power to abate the acceleration; ATS-OFF; Power Idle; and SPEED BRAKES FLIGHT DETENT. Our altitude variation was over 50-180 feet; Denver ARTCC gave us a 30 degrees offsite vector to the right with a block altitude FL410-390; and we reported the severe mountain wave. I used Control Wheel Steering Pitch to maintain level attitude; thereafter over PUB the event receded. It lasted only four seconds; but was definitely severe and unforecasted at that location. Both Maintenance and Dispatch were advised and a write up was entered.Preventative Measures: Better MTW forecast and predictions. Alternate routing. But the MTW was unpredictable and very localized; seemed in the wake of Pike's Peak.
B737 Captain reported encountering severe mountain wave in the vicinity of PUB that resulted in speed and altitude excursions.