The Air Survival skill is used passively it allows you to fly over surfaces and areas that might otherwise be inaccessible.
Air Survival can be used instead of Water or Fire Survival for accessing specific tiles, although it may not be used to access such places within buildings as there may not be enough room to take over.
Air Survival can not be used to replace Cold survival as it is assumed that the cold temperatures will hamper your ability to fly.
The different terrains are shown below together with the skills they are linked to.
Additional Information
As with all of the survival skills Air Survival can be obtained from finding items that contain the Air Survival bonus on them.
Air Survival can also be acquired through mounting any of the following pets:
You can also consume certain food items and/or potions to acquire the Air Survival skill.