The Jero/Farman H.F.23bis was a longer-range development of the H.F.20 for which the wingspan has been increased from 13.50m to 16 m (5 more wing spars outside the oblique strut) and a larger fuel tank was added (the tank sits on top of the fuselage sides instead of in between them). These modifications allowed flights of up to 4.30 hours or some 400 km.  The additional weight however restricted speeds to 95 km/h. The original power plant of the H.F.23bis was the 80 hp Gnome Monosoupape rotary engine, later on some aircraft had their engine replaced by a 80hp Le Rhône engine . At least eight H.F.23bis' were delivered in 1914 before the start of World War I and 2 more followed in August 1914.