Incident Narrative
The pilot stated that while conducting an approach to runway 6 in dusk conditions, the aircraft suddenly developed an uncommanded sink rate. In response, he applied engine power and raised the nose to a climb attitude. Shortly thereafter, he perceived a "thud beneath the aircraft" and noticed that the indicator light for the right main landing gear no longer showed a down-and-locked status. Believing that the right main gear had detached, the pilot initiated a go-around.
Landing Sequence
For the subsequent landing on runway 24, the pilot shut down the engines and used aileron inputs to keep the right wing elevated for as long as possible. As the aircraft decelerated, the right wing gradually lowered, causing the aircraft to veer off the right side of the runway.
Evidence
Examination of the runway area short of the threshold of runway 6 revealed gouges consistent with the right main landing gear contacting the ground and separating from the aircraft.