He then discovered, to his surprise, that the Langley fighters were not headed north toward the Baltimore area as instructed, but east over the ocean.
( He ( then ( ( ( ( ( discovered , ) ( to ( his surprise ) ) ) , ) ( that ( ( the ( Langley fighters ) ) ( ( were not ) ( ( headed ( north ( toward ( the ( Baltimore area ) ) ) ) ) ( ( as instructed ) ( , ( but ( east ( over ( the ocean ) ) ) ) ) ) ) ) ) ) ) . ) ) )
(ROOT (S (NP (PRP He)) (ADVP (RB then)) (VP (VBD discovered) (, ,) (PP (TO to) (NP (PRP$ his) (NN surprise))) (, ,) (SBAR (IN that) (S (NP (DT the) (NNP Langley) (NNS fighters)) (VP (VBD were) (RB not) (VP (VBN headed) (ADVP (RB north) (PP (IN toward) (NP (DT the) (NNP Baltimore) (NN area)))) (UCP (SBAR (IN as) (S (VP (VBD instructed)))) (, ,) (CC but) (ADVP (JJ east) (PP (IN over) (NP (DT the) (NN ocean)))))))))) (. .)))
The fighters were going in the wrong direction. 
( ( The fighters ) ( ( were ( going ( in ( the ( wrong direction ) ) ) ) ) . ) )
(ROOT (S (NP (DT The) (NNS fighters)) (VP (VBD were) (VP (VBG going) (PP (IN in) (NP (DT the) (JJ wrong) (NN direction))))) (. .)))