The Dodo Bird

 The Flying Nun 106 Flight Of The Dodo Bird

She explains her ability to fly by stating, "When lift plus thrust is greater than load plus drag, anything can fly." In one episode, she tries to gain weight so she could stay grounded, but the attempt fails. Additionally, in the first-season episode "Young Man with a Cornette," she specifically tells a young boy who intended to use her cornette to fly that there were many factors other than her weight (which was distributed differently from that of the boy) that made her flying possible. She was unable to take off when heavy rains caused her starched cornette to lose its shape, when she had to wear something that would keep her grounded at all times, or, on one occasion in the episode titled "The Flying Dodo", when an inner ear infection caused her to lose her balance.

For a series often accused of being outlandish (often by its title rather than its true content), The Flying Nun treated Sister Bertrille's gift of flight more realistically than other fantasy comedies of the era. Usually on fantasy series of the 1960s, there were frantic and elaborate attempts to hide and keep secret the special powers, a constant dilemma on Bewitched, I Dream of Jeannie and My Favorite Martian. In most cases, The Flying Nun dealt with its premise more logically. Quite often, Sister Bertrille and the nuns freely admitted her ability to fly, asking for discretion in hopes that it would not draw attention to the needs and efforts of the convent. Secrecy was only necessary (and occasionally humorously so) for any characters who would not understand, or might make the situation exploitative, widely public, subject to ridicule, or otherwise disruptive.