flight path vs air lane

flight path and air lane both are nouns.

Word	Noun	Adjective	Verb	Adverb
flight path	Yes	No	No	No
air lane	Yes	No	No	No

As nouns, flight path and air lane are synonyms defined as:

flight path and air lane: a designated route followed by airplanes in flying from one airport to another

Other synonyms of flight path include airway, skyway.

flight path (noun)	air lane (noun)
a designated route followed by airplanes in flying from one airport to another	a designated route followed by airplanes in flying from one airport to another
the path of a rocket or projectile or aircraft through the air