aviation vs air travel

aviation and air travel both are nouns.

Word	Noun	Adjective	Verb	Adverb
aviation	Yes	No	No	No
air travel	Yes	No	No	No

As nouns, aviation and air travel are synonyms defined as:

Other synonyms of aviation include air.

aviation (noun)	air travel (noun)
travel via aircraft	travel via aircraft
the art of operating aircraft
the aggregation of a country's military aircraft
the operation of aircraft to provide transportation