What happened
The pilot reported that during an instrument flight rules cruise at 13,000 feet, the aircraft was flying near the tops of ragged cumulus build-ups. He estimated being approximately 200 to 300 feet below the top of one cloud when severe turbulence was encountered. During this encounter, the aircraft experienced a loss of altitude between 1,500 and 2,000 feet and sustained substantial damage.
Following the event, the pilot noted that the 'gear up' light was not illuminated, the airspeed indicator was inoperative, and some rivets had popped on the wings. At the destination airport, he was unable to extend the landing gear using either the normal or emergency systems. He then diverted to Redbird Airport and made a wheels-up landing, which resulted in minimal additional damage.
The pre-flight weather briefing had called for turbulence along the route with occasional light to moderate activity below 8,000 feet. The pilot reported experiencing smooth conditions prior to the accident.
The investigation
After the aircraft was placed on jacks and the landing gear motor release handle was 'jiggled,' the normal and emergency gear extension systems operated normally.