At 9:27, after having been in the air for 45 minutes, United 93 acknowledged a transmission from the Cleveland Center controller.
( ( At 9:27 ) ( , ( ( after ( having ( ( been ( in ( the air ) ) ) ( for ( 45 minutes ) ) ) ) ) ( , ( ( United 93 ) ( ( ( acknowledged ( a transmission ) ) ( from ( the ( Cleveland ( Center controller ) ) ) ) ) . ) ) ) ) ) )
(ROOT (S (PP (IN At) (NP (CD 9:27))) (, ,) (PP (IN after) (S (VP (VBG having) (VP (VBN been) (PP (IN in) (NP (DT the) (NN air))) (PP (IN for) (NP (CD 45) (NNS minutes))))))) (, ,) (NP (NNP United) (CD 93)) (VP (VBD acknowledged) (NP (DT a) (NN transmission)) (PP (IN from) (NP (DT the) (NNP Cleveland) (NNP Center) (NN controller)))) (. .)))
At 9:27, United 93 interacted with the Cleveland Center controller.
( ( At 9:27 ) ( , ( ( United 93 ) ( ( interacted ( with ( the ( Cleveland ( Center controller ) ) ) ) ) . ) ) ) )
(ROOT (S (PP (IN At) (NP (CD 9:27))) (, ,) (NP (NNP United) (CD 93)) (VP (VBD interacted) (PP (IN with) (NP (DT the) (NNP Cleveland) (NNP Center) (NN controller)))) (. .)))