Uh, they're speculating it's from the aircraft.
( Uh ( , ( they ( ( 're ( speculating ( it ( 's ( from ( the aircraft ) ) ) ) ) ) . ) ) ) )
(ROOT (S (ADVP (RB Uh)) (, ,) (NP (PRP they)) (VP (VBP 're) (VP (VBG speculating) (SBAR (S (NP (PRP it)) (VP (VBZ 's) (PP (IN from) (NP (DT the) (NN aircraft)))))))) (. .)))
They think it is from the aircraft.
( They ( ( think ( it ( is ( from ( the aircraft ) ) ) ) ) . ) )
(ROOT (S (NP (PRP They)) (VP (VBP think) (SBAR (S (NP (PRP it)) (VP (VBZ is) (PP (IN from) (NP (DT the) (NN aircraft))))))) (. .)))