During the 1920s, Greece took its first tangible steps towards an indigenous aeroplane manufacturing capability with the establishment of its State Aircraft Factory (SAF). its first offering became the "Velos" of 1926 based in the Blackburn "Dart" torpedo bomber biplane. Following this modestly successful debut was the "Chelidon" (translating to "Swallow") of 1927 which was developed, again with assistance from Blackburn, to satisfy a Hellenic Navy requirement - this time for a two-seat advanced trainer / reconnaissance platform. However, despite some eighteen units ordered by the Navy service, only a single prototype ever materialized.
After just eight weeks of design and development work, the aircraft was unveiled for its first flight on February 20th, 1927. Key design features included its single-bay biplane wing arrangement, twin tandem seating, and Salmson 9AC 9-cylinder air-cooled radial piston engine of 120 horsepower installed at the nose. The engine drove a two-bladed propeller in typical fashion and ground-running was accomplished through a "tail-dragger" arrangement featuring a fixed twin-wheeled support at forward center mass and a simple skid at the rear. Like the Velos before it, the Chelidon was designed as configurable, from a land-based plane to seaplane and back again as needed.
As finalized, the aircraft sported a running length of 19 feet and a wingspan of 26.9 feet. Maximum speed, as tested, reached 93 miles-per-hour, suitable for the roles envisioned of the machine. Future serial production was to involve the Armstrong Siddeley "Lynx" engine for improved power and performance but was not to be.
Before the end of 1926, the Hellenic Navy committed to an order for eighteen of the type until it was found, through additional testing, that the design was more-or-less obsolescent when compared to contemporaries of the day. As such, the sole completed prototype example was relegated to training for SAF company personnel and managed to survive until 1938 before being given up for good.