On July 22, 2020, about 1100 central daylight time, a Beech 400, N425BJ, was substantially damaged when it was involved in an accident at Montgomery Regional Airport (MGM), Montgomery, Alabama. The two pilots and one passenger were not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. According to the pilot, after extending the landing gear for landing, he did not receive a positive indication that the left main landing gear was down and locked. The pilot referred to the airplane’s emergency procedures for manual landing gear extension, but this procedure failed to extend the gear. The pilot then elected to shut down the left engine and land with the left main landing gear retracted. During landing, the pilot was able to keep the airplane on the runway surface. The left wing was substantially damaged from contact with the runway surface. During postaccident examination by a mechanic, the landing gear and doors would not retract or extend normally after multiple attempts. Troubleshooting identified the landing gear control unit as the possible source of the anomalies. The landing gear control unit was replaced, and the landing gear functioned normally.