Farman F.121 Jabiru / F.3X / F.4X

The nine-passenger F.121 was originally known as the F.3X and was a high-mounted wing, deep slab-sided fuselage aircraft powered by four 134kW Hispano-Suiza 8Ac engines in tandem pairs. The F.121 won the 1923 French Grand Prix des Avions Transports and 500,000 francs. At least three different radiator arrangements were tried in attempts to cure the Jabiru's chronic cooling problems.

Four flew on the Farman airline's Paris-Brussels-Amsterdam route from 1926 and Danish Air Lines used a few between Amsterdam and Copenhagen. Four even uglier F.4X six-passenger aircraft followed, each with three uncowled 223.5kW Salmson Az.9 engines, two engines mounted above the landing gear on the lower stub wings and one in the upper fuselage nose. These served with Compagnie Internationale de Navigation Aerienne (formerly CFRNA) along with the more attractive Caudron 81 and Potez 32.

Passengers sat in wicker chairs angled towards the centre, and had a view from the continuous row of windows around the cabin.

Military Jabirus also appeared as prototype heavy bombers and escort fighters with stepped noses, each carrying twin Lewis guns on a Scarff ring in a nose cockpit and light bombs in a fuselage bay. Heavier bombs or, a torpedo could be carried under the fuselage.

Engine: 4 x HS 8AC, 132kW
Max take-off weight: 5000 kg / 11023 lb
Empty weight: 3000 kg / 6614 lb
Wingspan: 19.0 m / 62 ft 4 in
Length: 13.7 m / 44 ft 11 in
Wing area: 80.0 sq.m / 861.11 sq ft
Max. speed: 180 km/h / 112 mph
Ceiling: 4000 m / 13100 ft
Range w/max.fuel: 600 km / 373 miles
Crew: 1-2
Passengers: 9