Narrative:

At FL200 in cruise to ZZZ; we were experiencing continuous moderate turbulence for the majority of the flight. The seat belt sign was on and the fas (flight attendants) were seated when we suddenly experienced severe/extreme turbulence 50 miles northeast of ZZZ1. The event lasted approximately 20 seconds and we encountered airspeed deviations of +/- 20 knots and altitude deviations of +/- 200 feet. The aircraft was briefly uncontrollable. We were maintaining 270 knots when we experienced this encounter. We did not experience any indications of an over-speed. During this encounter we immediately made a report with ATC and were cleared to descend to 17;000 MSL. We then confirmed the safety of our fas and passengers and then sent a message to dispatch via ACARS.we then continued in moderate turbulence and began a descent into ZZZ. At 13;000 feet over ZZZ2 we experienced approximately 10-15 seconds of severe/extreme turbulence again; made the notification to ATC and again confirmed everyone was stilled seated. We received reports from the preceeding aircraft on the approach into ZZZ; which indicated occasional moderate turbulence and a ceiling of approximately 1;000 feet. We continued the approach and landing at ZZZ with no further incident and immediately contacted dispatch and maintenance control at the gate.

Google
 

Original NASA ASRS Text

Title: EMB-175 Captain reported severe turbulence encounter resulting in momentary loss of control.

Narrative: At FL200 in cruise to ZZZ; we were experiencing continuous moderate turbulence for the majority of the flight. The seat belt sign was on and the FAs (Flight Attendants) were seated when we suddenly experienced severe/extreme turbulence 50 miles NE of ZZZ1. The event lasted approximately 20 seconds and we encountered airspeed deviations of +/- 20 knots and altitude deviations of +/- 200 feet. The aircraft was briefly uncontrollable. We were maintaining 270 knots when we experienced this encounter. We did not experience any indications of an over-speed. During this encounter we immediately made a report with ATC and were cleared to descend to 17;000 MSL. We then confirmed the safety of our FAs and passengers and then sent a message to Dispatch via ACARS.We then continued in moderate turbulence and began a descent into ZZZ. At 13;000 feet over ZZZ2 we experienced approximately 10-15 seconds of severe/extreme turbulence again; made the notification to ATC and again confirmed everyone was stilled seated. We received reports from the preceeding aircraft on the approach into ZZZ; which indicated occasional moderate turbulence and a ceiling of approximately 1;000 feet. We continued the approach and landing at ZZZ with no further incident and immediately contacted Dispatch and Maintenance Control at the gate.

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.