The Chelidon (Χελιδών, meaning 'Swallow' in Greek, also spelled in English as Helithon) was the first airplane developed by the Greek EAF (later known as KEA) aircraft factory (with factory management still provided by Blackburn Aircraft Limited). Its development was completed in a virtually record time of 8 weeks, and first flight was made on February 11, 1927. According to some sources, a British engineer participated in the Greek design team, which developed the plane according to the Greek Navy specifications. It was a two-seater military biplane designed for advanced training and other roles including surveillance, requiring only basic maintenance facilities. It could also be transformed into a hydroplane. It used a Salmson 120hp engine (future variants were to use Armstrong Siddeley Lynx engine) and had a maximum speed of 150 km/h. No further production followed, as, after testing, it was considered inferior to alternative models proposed for the Greek Navy. The one built was mostly used for training and was retired in 1938.