That aircraft was United 93.
( ( That aircraft ) ( ( was ( United 93 ) ) . ) )
(ROOT (S (NP (DT That) (NN aircraft)) (VP (VBD was) (NP (NNP United) (CD 93))) (. .)))
United 93 was headed for New York.
( ( United 93 ) ( ( was ( headed ( for ( New York ) ) ) ) . ) )
(ROOT (S (NP (NNP United) (CD 93)) (VP (VBD was) (VP (VBN headed) (PP (IN for) (NP (NNP New) (NNP York))))) (. .)))