The Legend of Korra - Book 3 (Change)
Episode 7: "Original Airbenders"
Description: At the Northern Air Temple, Tenzin finds it increasingly difficult to teach the new airbenders about the peaceful ways and culture of the Air Nomads. Bumi suggests that he become more demanding and back-up his new recruits with an iron fist. Unfortunately, this causes tension between them all, leading Bumi to quit and all of the other airbenders to feel overworked and wish to return home to their families.