In 1940, the U.S. Navy acquired the land that would eventually become Naval Air Station Oceana. At that time, the surrounding area was mainly farmland susceptible to flooding, but it served as a useful outlying field for the rapidly expanding Naval Air Force centered at NAS Norfolk and allowed units to work up for deployments away from the crowded base there. Airspace and airfield facility restrictions precluded NAS Norfolk from serving as the home station for tactical air units, and in the 1950s NAS Oceana was expanded to Master Jet Base-status to serve that purpose. NAS Oceana has grown to become one of the largest and most advanced air stations in the world, comprising 6,820 acres (including Dam Neck Annex). Obstruction clearances and flight easements total an additional . Its four runways, three measuring in length and one measuring 12,000 feet, are designed for high-performance aircraft. NAS Oceana's primary mission is to train and deploy the Navy's Atlantic Fleet strike fighter squadrons of F/A-18 Hornets and Super Hornets. Naval Aviators and Naval Flight Officers stationed at NAS Oceana fly approximately 219,000 training operations each year.