The other aircraft referred to by New York Center was United 175.
( ( ( The ( other aircraft ) ) ( ( referred to ) ( by ( New ( York Center ) ) ) ) ) ( ( was ( United 175 ) ) . ) )
(ROOT (S (NP (NP (DT The) (JJ other) (NN aircraft)) (VP (VBN referred) (S (VP (TO to))) (PP (IN by) (NP (NNP New) (NNP York) (NNP Center))))) (VP (VBD was) (NP (NNP United) (CD 175))) (. .)))
New York Center mentioned two aircrafts, including United 175.
( ( New ( York Center ) ) ( ( mentioned ( ( ( two aircrafts ) , ) ( including ( United 175 ) ) ) ) . ) )
(ROOT (S (NP (NNP New) (NNP York) (NNP Center)) (VP (VBD mentioned) (NP (NP (CD two) (NNS aircrafts)) (, ,) (PP (VBG including) (NP (NNP United) (CD 175))))) (. .)))