The SBD was also flown by the United States Marine Corps, both from land air bases and aircraft carriers. The SBD is best remembered as the bomber that delivered the fatal blows to the Japanese carriers at the Battle of Midway in June 1942. The type earned its nickname "Slow But Deadly" (from its SBD initials) during this period. During its combat service, the SBD proved to be an excellent naval scout plane and dive bomber. It possessed long range, good handling characteristics, maneuverability, potent bomb load, great diving characteristics from the perforated dive brakes, good defensive armament, and ruggedness. One land-based variant of the SBD – omitting the arrestor hook — was purpose-built for the U.S. Army Air Forces, as the A-24 Banshee. Design work on the Northrop BT-1 began in 1935. In 1937, the Northrop Corporation was taken over by Douglas, and the active Northrop projects continued under Douglas Aircraft Corporation. The Northrop BT-2 was developed from the BT-1 by modifications ordered in November 1937, and provided the basis of the SBD, which first entered service in mid-1939. Ed Heinemann led a team of designers who considered a development with a 1,000 hp (750 kW) Wright Cyclone engine. The plane was developed at the Douglas El Segundo, CA plant, and that facility, along with the company's Oklahoma City plant, built almost all the SBDs produced. One year earlier, both the U.S. Navy and Marine Corps had placed orders for the new dive bomber, designated the SBD-1 and SBD-2 (the latter had increased fuel capacity and different armament). The SBD-1 went to the Marine Corps in late 1940, and the SBD-2 to the Navy in early 1941, replacing the SBU Corsair and Curtiss SBC Helldiver squadrons on US carriers. Distinctive perforated split flaps or "dive-brakes" had been incorporated into the BT-1 to eliminate tail buffeting during diving maneuvers. Unusual for carrier aircraft, folding wings were not chosen for the design, opting instead for structural strength. For more information on development and design, operational history and variants, click here.