The Rohrbach Ro XI Rostra was a flying boat built in Germany in 1928 for use as a transatlantic mail plane.

[1] The Ro XI shared the same general configuration its predecessor, the Ro V Rocco: a conventional, high-wing flying boat with cruciform empennage and two engines mounted tractor-fashion in nacelles mounted on struts above the wing.

[1] The aircraft featured a set of masts and sails that could be deployed for extended travel on water in the event of a forced landing.

[4] In middle of 1929, the Rostra made a preliminary 1,760 km (1,090 mi) round trip between Travemünde and Stockholm carrying ten passengers, and a longer-range flight to Iceland was planned.

[5] Data from Rohrbach Ro XI Rostra - Histaviation [6]General characteristics Performance