U.S. Air Force Combat Controller students do a thirty-foot low crawl under barbed wire. U.S. Air Force Combat Controller students do a thirty-foot low crawl under barbed wire during a confidence course at Hurlburt Field, Fla., on June 9, 2005. The students of Class 013, Advanced Skills Training, will graduate June 10th. SHARE: Download: Full Size (0.04 MB) Credit: VIRIN: 090756-D-GJO70-532.jpg Photo Gallery