FAA headquarters had by this time established an open line of communication with the Command Center at Herndon and instructed it to poll all its centers about suspect aircraft.
( ( FAA headquarters ) ( ( ( had ( by ( this time ) ) ) ( ( ( ( ( established ( ( an ( open line ) ) ( of communication ) ) ) ( with ( the ( Command Center ) ) ) ) ( at Herndon ) ) and ) ( instructed ( it ( to ( ( poll ( all ( its centers ) ) ) ( about ( suspect aircraft ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NNP FAA) (NNS headquarters)) (VP (VBD had) (PP (IN by) (NP (DT this) (NN time))) (VP (VP (VBN established) (NP (NP (DT an) (JJ open) (NN line)) (PP (IN of) (NP (NN communication)))) (PP (IN with) (NP (DT the) (NNP Command) (NNP Center))) (PP (IN at) (NP (NNP Herndon)))) (CC and) (VP (VBN instructed) (S (NP (PRP it)) (VP (TO to) (VP (VB poll) (NP (PDT all) (PRP$ its) (NNS centers)) (PP (IN about) (NP (NN suspect) (NN aircraft))))))))) (. .)))
FAA headquarters refused to communicate with the Command Center at Herndon.
( ( FAA headquarters ) ( ( refused ( to ( ( communicate ( with ( the ( Command Center ) ) ) ) ( at Herndon ) ) ) ) . ) )
(ROOT (S (NP (NNP FAA) (NNS headquarters)) (VP (VBD refused) (S (VP (TO to) (VP (VB communicate) (PP (IN with) (NP (DT the) (NNP Command) (NNP Center))) (PP (IN at) (NP (NNP Herndon))))))) (. .)))