U.S. Air Force airmen and Royal Australian air force airfield defense guards work to eliminate an opposing force as part of a combat scenario during exercise Cope North 15, on Feb. 23, 2015, at the Commando Warrior Pacific Regional Training Center on Andersen Air Force Base, Guam. (Jason Robertson/U.S. Air Force)

U.S. Air Force, Japan Air Self-Defense Force and Royal Australian air force aircraft fly in formation during Cope North 15, on Feb. 17, 2015, off the coast of Guam. (Jason Robertson/U.S. Air Force)

Members of the U.S. Air Forces in Europe Band interact with the crowd during the Fasching parade on Feb. 17, 2015, in Ramstein-Miesenbach, Germany. The USAFE Band and approximately 1,400 other participants marched in the parade for more than two hours. (Timothy Moore/U.S. Air Force)

Students of the 364th Training Squadron's electrical systems course practice climbing power poles as part of a familiarization and trust exercise with the safety equipment on Feb. 3, 2015, at Sheppard Air Force Base, Texas. (Danny Webb/U.S. Air Force)

Honor guardsmen practice live-firing party movements on Feb. 9, 2015, at Ellsworth Air Force Base, S.D. (Zachary Hada/U.S. Air Force)

An F-15D Eagle takes off on Feb. 19, 2015, from Portland Air National Guard Base, Ore. The F-15 is assigned to the 142nd Fighter Wing. (John Hughel/U.S. Air National Gu)

Retired Air National Guard Chief Warrant Officer 2 Robert Hertel, laughs while under the wing of a P-47 Thunderbolt during the Heritage Flight Training and Certification Course on Feb. 28, 2015, at Davis-Monthan Air Force Base, Ariz. Hertel, a 92-year-old World War II veteran, was given the opportunity to visit the aircraft he used to fly. (Jensen Stidham/U.S. Air Force)