What happened
During the landing phase of flight, the pilot extended the landing gear while on the downwind leg. The pilot reported observing the three green landing gear position lights illuminated in the cockpit. To further verify the configuration, the pilot used a mirror mounted on the left engine nacelle to visually confirm that the nose landing gear was in the extended position.
As the aircraft approached the runway, the main landing gear made contact with the surface. At this moment, the pilot began to release elevator back pressure. Immediately following the contact of the main gear, the nose landing gear collapsed as it struck the runway.