Fractional aircraft flight crew reported difficulty controlling the aircraft in severe turbulence at FL450; experiencing significant altitude and speed deviations over a 20-minute period.
Synopsis
Fractional aircraft flight crew reported difficulty controlling the aircraft in severe turbulence at FL450; experiencing significant altitude and speed deviations over a 20-minute period.
Narrative
Flight was located off the BRK VOR on a 280 radial 20 miles between HBU VOR and waypoint DANDD at XA53z at FL450. Reported turbulence was severe and there were severe mountain waves. The bank angle went up to 30 degrees to the right. The autopilot disengaged. The speed oscillated between .61M and .82M. Vertical speed was +/- 2300 ft per minute. The altitude fluctuation was between FL437 and FL462. Conditions continued for about 20 minutes before it settled down. Crew was able to reengage the autopilot at that time. Stall warnings were received twice during the event. ATC was notified of the conditions and other traffic in the area reported the same severe turbulence conditions at various flight levels. Once able; the crew checked on the passengers; no injuries were reported; and the passengers advised they were fine. The flight continued successfully.Suggestions: I recommend using our data to generate discussion/education; training; & ideally a simulator scenario based on the event for recurrent training.
Second reporter narrative
Flight was located off the BRK VOR on a 280 radial 20 miles between HBU VOR and waypoint DANDD at XA53z at FL450. Reported turbulence was severe and there were severe mountain waves. The bank angle went up to 30 degrees to the right. The autopilot disengaged. The speed oscillated between .61M and .82M. Vertical speed was +/- 2300 ft per minute. The altitude fluctuation was between FL437 and FL462. Conditions continued for about 20 minutes before it settled down. Crew was able to reengage the autopilot at that time. Stall warnings were received twice during the event. ATC was notified of the conditions and other traffic in the area reported the same severe turbulence conditions at various flight levels. Once able; the crew checked on the passengers and no injuries were reported and the passengers advised they were fine. The flight continued successfully and uneventfully.
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.