U.S. Air Force AIRMAN 1ST Class Brad Frohner, of the 155th Air Refueling Wing, Nebraska Air National Guard, talks to a pilot during an Ability To Survive and Operate (ATSO) exercise at Lincoln Airport, Neb., on April 2, 2005. He is attired in Mission Oriented Protective Posture (MOPP) Level 4. (U.S. Air Force PHOTO by MASTER SGT. Alana Brown) (Released)