sucker on the plane

gullible person, will believe anything, will go along with any plan

He fell for the prank. He's a sucker on the plane.

sucker on the plane

BBC article: Dutch student boards a plane believing it was a plane to Australia, but turns out it was to Sydney, Nova Scotia.

This is a good example of a sucker on the plane. The student was gullible, trusting, and boarded a plane.

Quoting the above situation.
The dutch student is such a sucker on the plane!