Field is also home to Aviation Technical Services (ATS), one of the nation's largest aviation maintenance facilities. ATS operates a facility, formerly operated by Goodrich (formerly known as Tramco), and sold to ATS in the fall of 2007. ATS does 'heavy' checks for a number of airlines and cargo companies. According to their web page, they average 443 aircraft redeliveries each year. Paine Field is home to four flight schools – Chinook Flight Simulations, Regal Air, Northway Aviation, and Everett Helicopters – making it a popular destination for flight training. There are also a number of flying clubs on the field. The FAA-operated control tower maintains limited hours, operating only between 7 AM and 9 PM local time. During times that the tower is operational, both runways are active, but after hours, only runway 16R-34L is open. The airport has several natural reserves and sanctuaries around its perimeter, including ponds that were certified in 2019 as Salmon-Safe. History Paine Field was originally constructed in 1936 as a Works Progress Administration project. At the time of development, it was envisioned that the Airport would create jobs and economic growth in the region by becoming one of the ten new "super airports" around the country. Paine Field was taken over by the U.S. Army Air Corps prior to entry into World War II as a patrol, air defense, and fighter training base and was later controlled by the U.S. Army Air Forces. With the end of the war, the airfield began to be returned to the civilian control of Snohomish County. In 1947, as transition activities were still underway, military control of the then-Paine Army Airfield was transferred to the newly established U.S. Air Force, with the facility renamed Paine Field. Transfer of the property to the Snohomish County government was completed in 1948, however, the Air Force continued to maintain various Air Defense Command units at the airport as military tenants. Before Snohomish County could start planning for the continued development of a "super airport", the United States was again involved in an armed conflict—this time in Korea and also the breakout of the Cold War with the Soviet Union. When the Pacific Northwest defense installations were reviewed House Representative Henry M. Jackson recommended more military presence in the area and Paine Field was reactivated as a military airbase. Paine Field was returned to USAF control in 1951, renamed Paine Air