High Quality Content by WIKIPEDIA articles! The Ikarus IO (for Izvidjac Obalni, "Coastal Reconnaissance") was a biplane flying boat produced in Yugoslavia in the late 1920s. It was a conventional flying boat design for its day, featuring a large single-bay wing cellule, the staggered wings of slightly uneven span braced with N-struts. The pilot and observer sat side-by-side in an open cockpit, and a gunner sat in an open position ahead of them, on the bow. The pusher engine and frontal radiator were carried on struts in the interplane gap.