The operation was not cost  the United States lost two planes.
( ( The operation ) ( ( ( was not ) ( cost ( ( the ( United States ) ) ( lost ( two planes ) ) ) ) ) . ) )
(ROOT (S (NP (DT The) (NN operation)) (VP (VBD was) (RB not) (VP (VBN cost) (SBAR (S (NP (DT the) (NNP United) (NNPS States)) (VP (VBD lost) (NP (CD two) (NNS planes))))))) (. .)))
The operation ruined two US planes which crashed in Libya and were destroyed.
( ( The operation ) ( ( ruined ( ( two ( US planes ) ) ( which ( ( ( crashed ( in Libya ) ) and ) ( were destroyed ) ) ) ) ) . ) )
(ROOT (S (NP (DT The) (NN operation)) (VP (VBN ruined) (NP (NP (CD two) (NNP US) (NNS planes)) (SBAR (WHNP (WDT which)) (S (VP (VP (VBD crashed) (PP (IN in) (NP (NNP Libya)))) (CC and) (VP (VBD were) (VP (VBN destroyed)))))))) (. .)))