Planes, as in plural.
( Planes ( , ( ( as ( in plural ) ) . ) ) )
(ROOT (FRAG (NP (NNS Planes)) (, ,) (PP (RB as) (IN in) (NP (NN plural))) (. .)))
Thirty or forty planes.
( ( ( ( Thirty or ) forty ) planes ) . )
(ROOT (S (VP (VB Thirty) (CC or) (VB forty) (NP (NNS planes))) (. .)))