The first PBY-1 and the first production PBY. Can't quite make out the stencilled lettering at the near end of the wing - "Never [something]", I think.
Photo: 72-AC-55B-1 (1939-Mar-01)
Caption: Assembled airplane - port side. Photograph showing flap trailing edge. Flap installation upon completion of Trial Board changes on a Vought-Sikorsky aircraft.
(Photo courtesy of the Naval Historical Center, US Navy)