Before the events of Mortal Engines, the people of Airhaven got tired of constantly running from predators. So they inflated gas bags and flew into the air. The town travels through the air,
visiting different cities. The upper classes would be able to take trips up to visit the floating town.
It is the central place in the sky. As Airhaven is neutral, it has both tractionists and anti-tractionists. During the events of Mortal Engines, it is damaged by the stalker Shrike and it has to land on the ground to be repaired. When it is on the ground, Airhaven was almost devoured by the pirate town Turnbridge Wheels and only escapes due to Anna Fang in the Jenny Haniver.
In A Darkling Plain, even though it is a neutral town it houses mostly tractionists. Hester and Theo save Lady Naga from a slave trader. On the way out Shrike stabs a guard through the feet from below and
helps them escape. Nimrod Pennyroyal falls onto the safety net along with a rival news journalist.
The net breaks and they both fall down. Nimrod is rescued by Shrike while the jornalist plunges to his death.
It is unknown what happened to Airhaven after that.