Senior Airman Jared Callahan guides a passing A-10 on Jan. 16, 2013, during the Beverly Midnight excercise at Osan Air Base, South Korea. The exercise tests the airmen's ability to survive and operate in a war-time environment. Callahan was given the OK to take off his protective mask after wearing it for hours during the exercise. (Armando Limon/Stars and Stripes)

OSAN AIR BASE, South Korea — Throughout the year, U.S. servicemembers in South Korea holds exercises to help them keep their skills sharp and test their ability to respond to crises at a moment’s notice.

This week, airmen from Osan donned their Mission Oriented Protective Posture (MOPP) suits during Beverly Midnight Exercise 2013. The exercise allows leaders to evaulate the troops’ ability to survive and operate in a war-time environment. The training also tests the airmen’s ability to plan and execute an exercise.

Airmen are evaluated every quarter on their skills to survive and operate in a wartime environment, as well as defend the base, execute combat operations and receive follow-on forces, according to an Air Force news release.