Small Transport
Flight Crew Instrument; Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine
Flight Crew Last 90 Days 70; Flight Crew Total 4500; Flight Crew Type 1800
Deviation - Altitude Excursion From Assigned Altitude; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter Loss Of Aircraft Control; Inflight Event / Encounter Wake Vortex Encounter; Inflight Event / Encounter Weather / Turbulence
Air Traffic Control Issued Advisory / Alert; Flight Crew Returned To Clearance; Flight Crew Regained Aircraft Control
Weather; Environment - Non Weather Related; Procedure
We were cleared to 3;000 ft. on a wide base and a tight vector to ILS [Runway] 17L behind a heavy jet. It was very turbulent and our path put us downwind to the heavy jet. During the turbulence I lost control of the aircraft and we shot down about 500 ft. below our assigned altitude. I was in the process of correcting when the Approach Controller called out the fact we were off altitude. I told her we concurred and were correcting. I believe the issue was caused by the moderate to severe turbulence we were experiencing along with the wake from the heavy jet.
BE20 pilot reported loss of control resulting in uncommmanded 500' descent on arrival into SDF due to either severe turbulence or a wake encounter.