EMB ERJ 190/195 ER/LR
Flight Crew Multiengine; Flight Crew Instrument; Flight Crew Air Transport Pilot (ATP)
Deviation - Altitude Excursion From Assigned Altitude; Deviation - Speed All Types; Deviation - Track / Heading All Types; Inflight Event / Encounter Loss Of Aircraft Control; Inflight Event / Encounter Weather / Turbulence
Flight Crew Regained Aircraft Control; General Maintenance Action; General Flight Cancelled / Delayed
Weather
On descent; from approximately 11;000 to 5;000 feet on the arrival; we encountered severe to borderline extreme turbulence. The aircraft was configured with the gear up; flaps up; and airspeed bug speed set to 250 knots. The aircraft was on the autopilot in the flight level change mode and was unable to hold 250 knots. The airspeed varied by +/- 60 to 90 knots. The attitude was barely controllable and at one point the aircraft banked 30-40 degrees uncommanded. I used the touch control steering to attempt to control the attitude of the aircraft and decrease the airspeed; which at one point went well above redline. High speed warnings did occur. Then later in the descent; with the autopilot still engaged; the airspeed went as low as 220 knots. Loose items were thrown all over the place including EFBs; cell phones; the logbook; and even my headset was thrown from my head and hit the ceiling. Reports from the cabin were that some passengers hit the ceiling and the side walls; but no injuries were reported. At the beginning of the flight; everyone had been told to remain seated throughout the flight due to expected turbulence. The event occurred because of a large vertical shear as well as strong horizontal winds blowing in different directions below 16;000 feet. There were reports of severe turbulence in the form of SIGMETs in the flight paperwork; but there was no immediate or real time information available from ATC or dispatch. The flight plan turbulence index reported a 4 around [a waypoint on the arrival]; but as classification; this was not adequate. It should have been a 7. Before departing; I called dispatch to specifically ask about the weather enroute to ZZZ. Dispatch did not really give me much useful information in regards to the turbulence. In the future; it would be prudent for more attention to be paid to the PIREPs that caused the SIGMETs as they were very accurate as to location and intensity.
EMB190 Captain experiences severe turbulence caused by windshear during descent. Momentary loss of control occurs with airspeed varying from 220 knots to well above the barber pole while attempting to maintain 250 knots. The flight plan weather packet did not accurately portray the severity of the turbulence.