ground crew vs ground-service crew

ground crew and ground-service crew both are nouns.

Word	Noun	Adjective	Verb	Adverb
ground crew	Yes	No	No	No
ground-service crew	Yes	No	No	No

As nouns, ground crew and ground-service crew are synonyms defined as:

ground crew and ground-service crew: the crew of technicians and mechanics who service aircraft on the ground

ground crew (noun)	ground-service crew (noun)
the crew of technicians and mechanics who service aircraft on the ground	the crew of technicians and mechanics who service aircraft on the ground