cargo helicopter vs helicopter

cargo helicopter and helicopter both are nouns.

Word	Noun	Adjective	Verb	Adverb
cargo helicopter	Yes	No	No	No
helicopter	Yes	No	No	No

As nouns, helicopter is a hypernym of cargo helicopter; that is, helicopter is a word with a broader meaning than cargo helicopter:

cargo helicopter: a helicopter that carries cargo
helicopter: an aircraft without wings that obtains its lift from the rotation of overhead blades

Other hypernyms of cargo helicopter include chopper, eggbeater, whirlybird.

cargo helicopter (noun)	helicopter (noun)
a helicopter that carries cargo	an aircraft without wings that obtains its lift from the rotation of overhead blades