The Besson MB.35 Passe Partout was a French two-seat spotter and observation floatplane, designed by Besson.

It was intended to serve on Surcouf a very large (for its day) submarine, stowed in a sealed hangar.

[1] The first aircraft was destroyed during trials and the second was converted to the MB.41, prototype of the Besson MB.411, which did serve on Surcouf.

[2] Data from Jane's all the World's Aircraft 1928,[3] Biplanes, Triplanes, and Seaplanes,[1] Submarines with wings : the past, present and future of aircraft-carrying submarines[2]General characteristics Performance