Incident
During the flare to land, the captain and first officer reported that the right propeller beta light illuminated. Subsequently, the aircraft yawed to the right and descended with the right wing low, causing the right wing to contact the ground. The aircraft remained on the ground, traveled off the runway, and came to rest on grass adjacent to the runway.
Investigation
The aircraft was removed from the runway. The following day, under the supervision of the Federal Aviation Administration (FAA), the right engine and propeller were operationally tested. The tests revealed no evidence of malfunction in the propeller blade angle rigging, fuel flow, or worn flight idle gate.
According to the NTSB Form 6120.1/2, completed by the Director of Flight Operations, wake turbulence was suspected as a factor in the loss of control. However, no determination could be made as to the reason for the loss of control.