consists of 366 students, with 11 classes conducted per year. The vast majority of Ranger students have already graduated from Airborne School, and will make multiple jumps during the course. However, a small number of students have entered and completed Ranger School without being Airborne qualified. These individuals completed tasks assigned by cadre instead of taking part in the jumps alongside their classmates. Following the graduation of Captain Kristen Marie Griest and First Lieutenant Shaye Lynne Haver in August 2015, the Army announced that Ranger School would henceforth be open to female students. While acknowledging that in the past he "would have doubted a woman could pass the rigorous course", Brigade Command Sergeant Major Curtis Arnold described Griest and Haver as "tough soldiers" who "proved their mettle beyond a doubt" and "absolutely earned the respect of every ranger instructor". In October 2015, Major Lisa Jaster also graduated from Ranger School, becoming the first female Army Reserve officer to receive a Ranger tab. In 2019, First Lieutenant Chelsey Hibsch became the first female Air Force officer to graduate from Ranger School. Training Ranger School training has a basic scenario: the flourishing drug and terrorist operations of the enemy forces, the "Aragon Liberation Front," must be stopped. To do so, the Rangers will take the fight to their territory, the rough terrain surrounding Fort Benning, the mountains of northern Georgia, and the swamps and coast of Florida. Ranger students are given a clear mission, but they determine how to best execute it. The purpose of the course is learning to soldier as a combat leader while enduring the great mental and psychological stresses and physical fatigue of combat; the Ranger Instructors (RIs) – also known as Lane Graders – create and cultivate such a physical and mental environment. The course primarily comprises field craft instruction; students plan and execute daily patrolling, perform reconnaissance, ambushes, and raids against dispersed targets, followed by stealthy movement to a new patrol base to plan the next mission. Ranger students conduct about 20 hours of training per day, while consuming two or fewer meals daily totaling about , with an average of 3.5 hours of sleep a day. Students sleep more before a parachute jump for safety considerations. Ranger students typically wear and carry some of weapons, equipment, and training ammunition while patrolling more than throughout the course. Benning phase The first phase of Ranger School is