Cessna Citation Undifferentiated or Other Model
Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine
Inflight Event / Encounter Wake Vortex Encounter; Inflight Event / Encounter Loss Of Aircraft Control
Flight Crew Regained Aircraft Control
Environment - Non Weather Related; Procedure
Approximately 20 nm north of LAMMA intersection on CWRLD4 Arrival; in the vicinity of OMN VOR descending through FL210. Severe turbulence encounter. No injuries. No emergency declared. Passengers were seated at the time of incident. Seat belt sign was off due to smooth ride before the incident. While descending through FL210; [we] encountered a sudden onset of severe turbulence with no warning. Airplane rolled uncommanded into a right bank of approximately 70 degrees in less than one second. Autopilot was on at the time and disconnected automatically due to the upset. Crew recovered back to level flight within 5 seconds. Some light turbulence after the initial roll and recovery. Total time of event from beginning to end was approximately 10 seconds. Smooth ride before and after the encounter. No convective activity or wind shear noted. Weather was clear VMC. Suspect wake turbulence encounter. No damage or issues from the incident were observed and crew elected to continue to planned destination airport and land. Severe turbulence reported to ATC due to momentary loss of control. Suspected wake turbulence encounter. ATC may not have provided the correct spacing between us and a heavy aircraft. Unknown what the spacing was; or the type of aircraft; but other traffic was noted on the TCAS display in the vicinity.
Citation Captain reported momentary loss of control from a wake turbulence encounter descending through FL210 inbound to ISM.