What happened
The aircraft was conducting a landing approach under Instrument Meteorological Conditions (IMC). During the transition from IFR to VFR flight rules, airspeed decayed. The co-pilot assumed control of the aircraft, believing he had better visual reference to the runway than the pilot flying.
As the co-pilot lowered the nose and attempted to correct the aircraft's alignment for landing, it stalled approximately 5 feet above ground level. Despite the stall, the right wing dragged on the runway surface during touchdown. The aircraft eventually landed on the runway centerline and rolled out normally without further incident.
The flight crew remained unaware of the wing strike until a passenger inquired about sparks emanating from the right side of the plane. The co-pilot later stated that he believed his intervention prevented the situation from worsening.
Findings
Contributing factors included the loss of airspeed during the critical phase of transitioning between flight rules and the misalignment with the runway upon breaking out of clouds. The stall occurred due to improper pitch control during the recovery attempt.