U.S. Air Force Senior Airman Audrey Allen, 86th Aeromedical Evacuation Squadron aeromedical evacuation technician and flight instructor, applies a chest cover to a mannequin at Ramstein Air Base, Germany, Aug. 5, 2021. When air is being sucked into a person’s chest from a hole other than the trachea, chest covers are used to treat it and seal the hole. The training she facilitates helps the 86 AES provide aeromedical support throughout the European theater. (U.S. Air Force photo by Airman 1st Class Madelyn Keech)