High Quality Content by WIKIPEDIA articles! The Blackburn Iris was a British three-engined biplane flying boat of the 1920s. Although only five Irises were built, it was used as a long-ranged maritime reconnaissance aircraft by the Royal Air Force, where it equipped a squadron for 4 years, being used to carry out a number of notable long-distance flights. The final version of the Iris, the Iris Mark V was developed into the aircraft that replaced it in Squadron service, the Blackburn Perth.