Citation III; VI; VII (C650)
Flight Crew Air Transport Pilot (ATP); Flight Crew Flight Engineer; Flight Crew Multiengine; Flight Crew Instrument; Flight Crew Flight Instructor
Air Traffic Control Radar 8; Flight Crew Last 90 Days 70; Flight Crew Total 19500; Flight Crew Type 600
Confusion; Distraction; Human-Machine Interface
Aircraft Equipment Problem Less Severe; Inflight Event / Encounter Loss Of Aircraft Control
Flight Crew Became Reoriented; Flight Crew Regained Aircraft Control
Aircraft; Human Factors
Descending to assigned altitude of 13;000 ft traffic with below at 12;000 ft. The aircraft leveled off with autopilot in alt hold at 13;000 ft. I looked down at the FMS; selected direct to assigned intersection; looked up and aircraft was in a descending right hand turn. The Co-pilot indicated autopilot had disconnected and applied back pressure to regain altitude but because of bank co-pilots back pressure increased bank from standard rate angle of bank to 45 degrees of bank. The Pilot applied unusual attitude recovery procedures. Leveled wings then increased back pressure to climb back to assigned altitude of 13;000 ft. There was a loss of 500 ft with altitude deviation.
Pilot reported the auto pilot disconnected causing a temporary loss of control and altitude loss.