The Fokker S. IX was a military trainer aircraft produced in the Netherlands in the mid 1930s designed at a Royal Netherlands Navy request for a machine to replace the obsolete Fokker S. IIIs then in service. It was a conventional single-bay biplane with staggered wings of unequal span braced with N-struts. The pilot and instructor sat in tandem open cockpits and the undercarriage was of fixed tailskid type with divided main units.
Made by Fokker.