To our knowledge none of them had ever flown an actual airliner before.
( ( To ( our knowledge ) ) ( ( none ( of them ) ) ( ( ( had ever ) ( ( flown ( an ( actual airliner ) ) ) before ) ) . ) ) )
(ROOT (S (PP (TO To) (NP (PRP$ our) (NN knowledge))) (NP (NP (NN none)) (PP (IN of) (NP (PRP them)))) (VP (VBD had) (ADVP (RB ever)) (VP (VBN flown) (NP (DT an) (JJ actual) (NN airliner)) (ADVP (RB before)))) (. .)))
They were all expert pilots.
( They ( ( ( were all ) ( expert pilots ) ) . ) )
(ROOT (S (NP (PRP They)) (VP (VBD were) (RB all) (NP (NN expert) (NNS pilots))) (. .)))