U.S. Army Cpl. Terrence Patterson, a crew member assigned to B Company, 5th Battalion (General Support) Aviation, 159th Aviation Regiment, looks out the crew door of a CH-47 Chinook during a training mission at Felker Army Air Field, Fort Eustis, Va., Nov. 18, 2015. The training mission tested the Joint Survival Air Mask rotary wing variant next generation gas mask, which is designed to make Mission-Oriented Protective Posture Level 4 convenient, but effective. With the new gas mask, Soldiers only have to place the removable face plate on in the event of a chemical, biological or radiological threat. (U.S. Air Force photo by Senior Airman Breonna Veal)