The controller checked his radio equipment and contacted another controller at 8:53, saying that we may have a hijack and that he could not find the aircraft.
( ( The controller ) ( ( ( ( ( ( checked ( his ( radio equipment ) ) ) and ) ( ( contacted ( another controller ) ) ( at 8:53 ) ) ) , ) ( saying ( ( ( that ( we ( may ( have ( a hijack ) ) ) ) ) and ) ( that ( he ( ( could not ) ( find ( the aircraft ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (DT The) (NN controller)) (VP (VP (VBD checked) (NP (PRP$ his) (NN radio) (NN equipment))) (CC and) (VP (VBD contacted) (NP (DT another) (NN controller)) (PP (IN at) (NP (CD 8:53)))) (, ,) (S (VP (VBG saying) (SBAR (SBAR (IN that) (S (NP (PRP we)) (VP (MD may) (VP (VB have) (NP (DT a) (NN hijack)))))) (CC and) (SBAR (IN that) (S (NP (PRP he)) (VP (MD could) (RB not) (VP (VB find) (NP (DT the) (NN aircraft)))))))))) (. .)))
The controller had contacted another controller.
( ( The controller ) ( ( had ( contacted ( another controller ) ) ) . ) )
(ROOT (S (NP (DT The) (NN controller)) (VP (VBD had) (VP (VBN contacted) (NP (DT another) (NN controller)))) (. .)))