FARMAN HF.20

History

A French reconnaissance platform built shortly before and during the First World War, the Farman HF.20 took to the skies first in 1913, and was produced in a number of variants. 

A single example was purchased by the Hellenic Navy in mid to late 1912, initially based in Larissa in October 1912. Transferred in mid-November to Nikopolis in North-West Greece, the aircraft formed the Epirus Air Service Detachment alongside a number of Farman MF.7s. 

Throughout the following month it was used on multiple reconnaissance sorties during the First Balkan War, but it would ultimately be short-lived, as in late December the aircraft was lost in a crash.

The HF.22, essentially a modification of the HF.20 with added two pontoons thus turning the aircraft into a hydroplane, featured a slightly increased wingspan, but was otherwise identical to its predecessor. 3-4 of these aircraft were ordered in late 1914, used as trainers in the Naval Flying Corps at Palaio Faliro in Athens. These aircraft remained in service until at least 1918, when they are last mentioned by records as being stationed at Palaio Faliro. 

The Farman HF.27 introduced a further increased wingspan, all metal fittings in the booms, and a Canton-Unné R9 9-cylinder engine, which upped power to 155 horsepower and remedied the lack of power of previous variants. These aircraft would see service with the Hellenic Aviation Service during the First World War. 4 were ordered, equipping the "Z" Squadron in the Aegean Sea until being replaced by the Sopwith 1 1⁄2 Strutter in 1917. In action, one of the HF.27s (piloted by Dimitrios Argyropoulos) was shot down by a German Fokker.

After the war, the three remaining aircraft were returned to Greece, though in poor condition after extensive use, and so were scrapped sometime afterwards.

Design

Built of wooden frames and struts, skinned in canvas, the HF.20 featured a central gondola, occupied by the pilot and observer, behind which was located the Gnome Lambda rotary engine. The bottom wing, significantly shorter in span than the top, which slung under the gondola, whilst the rear fuselage was left unskinned. 

The aircraft was considered underpowered, the Gnome Lambda producing only 70 horsepower. This was not adequately addressed until the introduction of the 155 horsepower Canton-Unné R9 engine - though by the time this modification was trialled the aircraft was already considered obsolete.