Citation Latitude (C680A)
Flight Crew Instrument; Flight Crew Multiengine; Flight Crew Air Transport Pilot (ATP)
Deviation - Altitude Excursion From Assigned Altitude; Inflight Event / Encounter Weather / Turbulence; Inflight Event / Encounter Loss Of Aircraft Control
Flight Crew Regained Aircraft Control; Flight Crew Took Evasive Action
Weather
Severe turbulence encountered during arrival into ZZZ. At 36;000 FT and approximately .72M we encountered strong mountain wave type activity and a rapid uncontrolled descent. Autopilot came off and we were able to keep the wings somewhat level. Pilot flying was pulling back forcefully on the control wheel but we were still descending at 4000 ft/min. Pilot Monitoring deployed the speed brakes but speed kept increasing. Finally regained control after losing 4;000 feet of altitude.
CE680 Captain reported loss of aircraft control due to severe turbulence during cruise.