An Economic Assessment by the Tennessee Valley Authority says Arnold Engineering Development Center contributed more than $609 million to the Southern Middle Tennessee economy in 2015. While employment at the facility has steadily declined over the past decade, Arnold still accounts for nearly 2,000 direct jobs. TVA says the test facility also secured another 1,600 secondary jobs in the area. The economic report considered direct payroll, and money spent on supplies, utilities, fuel and other services used by the aerospace test facility. AEDC is the world’s largest test base and has an estimated replacement value of $11.6 billion.