Repeatedly between 10:14 and 10:19, a lieutenant colonel at the White House relayed to the NMCC that the Vice President had confirmed fighters were cleared to engage inbound aircraft if they could verify that the aircraft was hijacked.
( ( Repeatedly ( between ( ( 10:14 and ) 10:19 ) ) ) ( , ( ( ( a ( lieutenant colonel ) ) ( at ( the ( White House ) ) ) ) ( ( ( relayed ( to ( the NMCC ) ) ) ( that ( ( the ( Vice President ) ) ( had ( confirmed ( fighters ( were ( cleared ( to ( ( engage ( inbound aircraft ) ) ( if ( they ( could ( verify ( that ( ( the aircraft ) ( was hijacked ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) . ) ) ) )
(ROOT (S (PP (ADVP (RB Repeatedly)) (IN between) (NP (CD 10:14) (CC and) (CD 10:19))) (, ,) (NP (NP (DT a) (NN lieutenant) (NN colonel)) (PP (IN at) (NP (DT the) (NNP White) (NNP House)))) (VP (VBD relayed) (PP (TO to) (NP (DT the) (NN NMCC))) (SBAR (IN that) (S (NP (DT the) (NNP Vice) (NNP President)) (VP (VBD had) (VP (VBN confirmed) (SBAR (S (NP (NNS fighters)) (VP (VBD were) (VP (VBN cleared) (S (VP (TO to) (VP (VB engage) (NP (JJ inbound) (NN aircraft)) (SBAR (IN if) (S (NP (PRP they)) (VP (MD could) (VP (VB verify) (SBAR (IN that) (S (NP (DT the) (NN aircraft)) (VP (VBD was) (VP (VBN hijacked))))))))))))))))))))) (. .)))
Fighters were confirmed by the Vice President to engage aircraft that were hijacked.
( Fighters ( ( were ( ( confirmed ( by ( the ( Vice President ) ) ) ) ( to ( engage ( aircraft ( that ( were hijacked ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NNS Fighters)) (VP (VBD were) (VP (VBN confirmed) (PP (IN by) (NP (DT the) (NNP Vice) (NNP President))) (S (VP (TO to) (VP (VB engage) (NP (NP (NN aircraft)) (SBAR (WHNP (WDT that)) (S (VP (VBD were) (VP (VBN hijacked))))))))))) (. .)))