A dirigible was a type of aircraft used on Earth up to and during the 20th century. It used helium, which is lighter than air, to achieve flight.
While he was playing his holosuite program, Julian Bashir, Secret Agent, Doctor Bashir fell out of a dirigible, which made the character Anastasia Komananov believe he was dead. However, he had a parachute with him and found a submarine waiting for him when he landed. (DS9: "Our Man Bashir")