ground crew vs gang

ground crew and gang both are nouns.

Word	Noun	Adjective	Verb	Adverb
ground crew	Yes	No	No	No
gang	Yes	No	Yes	No

As nouns, gang is a hypernym of ground crew; that is, gang is a word with a broader meaning than ground crew:

ground crew: the crew of technicians and mechanics who service aircraft on the ground
gang: an organized group of workmen

Other hypernyms of ground crew include crew, work party.

ground crew (noun)	gang (noun)
the crew of technicians and mechanics who service aircraft on the ground	tool consisting of a combination of implements arranged to work together
	an organized group of workmen
	an association of criminals
	an informal body of friends

ground crew (verb)	gang (verb)
	act as an organized group