In the succeeding minutes, controllers were attempting to ascertain the altitude of the southbound flight.
( ( In ( the ( succeeding minutes ) ) ) ( , ( controllers ( ( were ( attempting ( to ( ascertain ( ( the altitude ) ( of ( the ( southbound flight ) ) ) ) ) ) ) ) . ) ) ) )
(ROOT (S (PP (IN In) (NP (DT the) (VBG succeeding) (NNS minutes))) (, ,) (NP (NNS controllers)) (VP (VBD were) (VP (VBG attempting) (S (VP (TO to) (VP (VB ascertain) (NP (NP (DT the) (NN altitude)) (PP (IN of) (NP (DT the) (JJ southbound) (NN flight))))))))) (. .)))
Controllers were able to see the altitude of the flight.
( Controllers ( ( were ( able ( to ( see ( ( the altitude ) ( of ( the flight ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NNS Controllers)) (VP (VBD were) (ADJP (JJ able) (S (VP (TO to) (VP (VB see) (NP (NP (DT the) (NN altitude)) (PP (IN of) (NP (DT the) (NN flight))))))))) (. .)))