This is the 4449th most frequent Russian word.
воздушном
"Воздушном" means "air" or "airy" in the sense of relating to air or atmosphere.
In this sentence, 'воздушном' is used as an adjective describing 'музее' (museum), meaning it pertains to air or aviation, specifically an air museum.
Мы встретились в воздушном музее.
We met at the air museum.
Here, 'воздушном' modifies 'пейзажем' (scenery), describing it as light, airy, or ethereal, characteristic of open air.
Она наслаждалась воздушным пейзажем за окном.
She enjoyed the airy scenery outside the window.
In this sentence, 'воздушном' refers to 'пространстве' (space), denoting that it is related to the air or the aerial environment.