In MILES (Multiple Integrated Laser Engagement System), and his Colt 5.56 mm M16A2 rifle at the ready, AIRMAN First Class Justin Mullins, USAF, 31st Security Forces Squadron, Aviano Air Base, Italy, approaches a mock town during a practice mission for the upcoming Defender Challenge Competition. Acting as the "Bad Guys" they also deploy to the field during the Ground Combat Skills, (GCS) training, a week long training regiment consisting of three days of classroom work and two days in the field where trainees receive instruction on land navigation, combat patrolling and field craft skills