group captain vs senior pilot

group captain and senior pilot both are nouns.

Word	Noun	Adjective	Verb	Adverb
group captain	Yes	No	No	No
senior pilot	Yes	No	No	No

As nouns, senior pilot is a hypernym of group captain; that is, senior pilot is a word with a broader meaning than group captain:

group captain: a commissioned officer (especially one in the Royal Air Force) equivalent in rank to a colonel in the army
senior pilot: the pilot in charge of an airship

Other hypernyms of group captain include captain.

group captain (noun)	senior pilot (noun)
a commissioned officer (especially one in the Royal Air Force) equivalent in rank to a colonel in the army	the pilot in charge of an airship