The prototype of the Fokker F.II, German c/n 4056, Dutch c/n 1500. From 1920 it was used as a research aircraft by the Netherlands civil aviation authority, RSL, without a registration - they could get away with that! Only in 1931 it was registered PH-RSL. Registration cancelled in 1936. Aircraft was bought back by Fokker and painted as early KLM machine H-NABC. Photo taken at airshow at Schiphol in 1938. Aircraft destined for prospective aviation museum but lost during the war. The real H-NABC (c/n 4057) became O-BAIC / OO-AIC with Sabena. Photo from: Amsterdam City Archives