Before the events of Mortal Engines, the people of Airhaven got tired of constantly running from predator cities, so they inflated gas bags and flew into the air. The town travels through the air, visiting different cities.
As Airhaven was neutral, it had both Tractionists and Anti-Tractionists. During the events of 1007 TE, it was damaged by the Stalker Shrike and had to land on the Black Island to be repaired. When it was being repaired, the pirate town Tunbridge Wheels made an unsuccessful attempt to eat it.
In 1026 TE, it had become divided between Tractionists and Anti-Tractionists. Hester Natsworthy and Theo saved Lady Naga from a slave trader, Napster Varley. On the way out Shrike stabbed a guard through the foot from below and helped them escape. Nimrod Pennyroyal fell onto the safety net along with a rival news journalist.
The net gave way and they both fell. Nimrod landed on an airship and was rescued by Shrike, while the journalist plunged to his death.
In the Mortal Engines film, Airhaven is not a town, but instead a gigantic, skeletal station for airships held aloft by a single giant balloon. The station has a number of docks, shops and restaurants built into it, but due to its skeletal nature can be very dangerous to visit, as no safety precautions are installed to save those who have fallen.
Similar to the novel, Airhaven is attacked by Shrike, who had caused a number of small explosions as a diversionary tactic. One of these explosions managed to reach the upper level of the station, causing the balloon system to rupture and sending Airhaven plummeting from the sky. The remains of the station combusted upon making contact with the Earth's surface, completely destroying it.