Player Embed Code: <iframe width='500' height='300' scrolling='no' frameborder='0' style='border: none; overflow: hidden; width: 500px; height: 300px;' allowtransparency='true' src='https://www.dvidshub.net/video/embed/155610'></iframe> Download Embed Share Osan units compete in Summer Safety Challenge Defense.gov Aug. 3, 2012 | 1:00 Units assigned to Osan Air Base compete in the annual Summer Safety Challenge. Practicing good operational risk management can not only help shape the mission, but also reduce mishaps.