Aurora Capital Group on Friday completed its acquisition of National Technical Systems Inc., a product engineering and testing company. Aurora, in Los Angeles, purchased National Technical of Calabasas for $267 million. National Technical, formerly a publicly traded company, is now a subsidiary of Aurora, a private equity firm with $2 billion in assets. The acquisition marks a new chapter for the company, said Chief Executive William McGinnis. “We see Aurora as a new partner with proven expertise in many of the markets we serve and with the shared goals of delivering world-class technology, innovation and service to our customers,” McGinnis said in a prepared statement. McGinnis and his executive team will stay on at National Technical under the new ownership. National Technical provides testing and engineering services for the aerospace, defense and transportation industries at facilities throughout the United States, including a 150 acre site in Santa Clarita.