Meanings

autumn sky

air cooling

conventional aircraft carrier (i.e. non-nuclear)

anti-aircraft gun

empty gun

anti-aircraft gun

vacant constituency

morning sky

air cargo

aeronautical engineering

air traffic control tower

blue sky

changeable weather

seismic gap

anti-aircraft weapon

flight (plane)

crematorium smoke rising in the sky

aviation insurance

blank email (e.g. for signing up to an email list)

air traffic controller