M*A*S*H - Season 1 Episode 17
Sometimes You Hear the Bullet

Frank throws his back out whilst spending the evening with Margaret, and ends up in traction. He promptly applies for the Purple Heart, having been technically wounded at a frontline unit. Tommy Gillis, an old friend of Hawkeyes, is writing a book about the war, and pays him a visit. Later, Tommy is brought into the camp, seriously wounded, and Hawkeye cant save him. A 15-year-old kid is in the hospital to have his appendix out. He joined up to be a hero back home, but Hawkeye has him sent home, giving him Franks purple heart.