The controller tracking American 77 told us he noticed the aircraft turning to the southwest, and then saw the data disappear.
( ( ( The controller ) ( tracking ( American 77 ) ) ) ( ( ( told us ) ( ( ( ( he ( noticed ( ( the aircraft ) ( turning ( to ( the southwest ) ) ) ) ) ) , ) and ) ( then ( saw ( ( the data ) disappear ) ) ) ) ) . ) )
(ROOT (S (NP (NP (DT The) (NN controller)) (VP (VBG tracking) (NP (NNP American) (CD 77)))) (VP (VBD told) (NP (PRP us)) (SBAR (S (NP (PRP he)) (VP (VBD noticed) (NP (NP (DT the) (NN aircraft)) (VP (VBG turning) (PP (TO to) (NP (DT the) (NN southwest))))))) (, ,) (CC and) (S (ADVP (RB then)) (VP (VBD saw) (SBAR (S (NP (DT the) (NNS data)) (VP (VBP disappear)))))))) (. .)))
According to the controller, the data for the aircraft disappeared after it turned to the southwest.
( ( According ( to ( the controller ) ) ) ( , ( ( ( the data ) ( for ( the aircraft ) ) ) ( ( disappeared ( after ( it ( turned ( to ( the southwest ) ) ) ) ) ) . ) ) ) )
(ROOT (S (PP (VBG According) (PP (TO to) (NP (DT the) (NN controller)))) (, ,) (NP (NP (DT the) (NNS data)) (PP (IN for) (NP (DT the) (NN aircraft)))) (VP (VBD disappeared) (SBAR (IN after) (S (NP (PRP it)) (VP (VBD turned) (PP (TO to) (NP (DT the) (NN southwest))))))) (. .)))