They assumed the fighter escort would be discreet, vectored to a position five miles directly behind the hijacked aircraft, where it could perform its mission to monitor the aircraft's flight path.
( They ( ( assumed ( ( the ( fighter escort ) ) ( would ( be ( ( ( ( discreet , ) ( vectored ( to ( ( a position ) ( ( five miles ) ( directly ( behind ( the ( hijacked aircraft ) ) ) ) ) ) ) ) ) , ) ( where ( it ( could ( perform ( its ( mission ( to ( monitor ( ( the ( aircraft 's ) ) ( flight path ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (PRP They)) (VP (VBD assumed) (SBAR (S (NP (DT the) (NN fighter) (NN escort)) (VP (MD would) (VP (VB be) (NP (NP (NN discreet)) (, ,) (VP (VBN vectored) (PP (TO to) (NP (NP (DT a) (NN position)) (ADVP (NP (CD five) (NNS miles)) (RB directly) (PP (IN behind) (NP (DT the) (JJ hijacked) (NN aircraft))))))) (, ,) (SBAR (WHADVP (WRB where)) (S (NP (PRP it)) (VP (MD could) (VP (VB perform) (NP (PRP$ its) (NN mission) (S (VP (TO to) (VP (VB monitor) (NP (NP (DT the) (NN aircraft) (POS 's)) (NN flight) (NN path)))))))))))))))) (. .)))
The mission was to be right behind the plane, not five miles away.
( ( The mission ) ( ( was ( to ( ( ( ( be right ) ( behind ( the plane ) ) ) , ) ( ( not ( five miles ) ) away ) ) ) ) . ) )
(ROOT (S (NP (DT The) (NN mission)) (VP (VBD was) (S (VP (TO to) (VP (VB be) (ADJP (JJ right)) (PP (IN behind) (NP (DT the) (NN plane))) (, ,) (ADVP (NP (RB not) (CD five) (NNS miles)) (RB away)))))) (. .)))