O.Thetford, P.Gray German Aircraft of the First World War (Putnam)
Friedrichshafen FF 44
This was the FF 34 aircraft (No. 117) rebuilt with a normal fuselage which bore the same naval number. It was a two-seat patrol seaplane in which a 240 h.p. Maybach Mb IV engine, fitted with reduction gears, was installed. Span, 18.4 m. (60 ft. 4 1/2 in.). Length, 10.85 m. (35 ft. 7 1/8 in.). Height, 4.25 m. (13 ft. 11 3/8 in.). Area, 68.5 sq.m. (740 sq.ft.). Weights: Empty, 1,562 kg. (3,436 lb.). Loaded, 2,305 kg. (5,071 lb.). Climb, 1,000 m. (3,280 ft.) in 8.8 min., 2,000 m. (6,560 ft.) in 22.1 min. Duration, 5 hr. Armament, one manually operated Parabellum machine-gun in rear cockpit.
J.Herris Friedrichshafen Aircraft of WWI (A Centennial Perspective on Great War Airplanes 21)
The FF34 was returned to Friedrichshafen on 22 April 1916 and delivered a second time on 4 May 1917, but was still determined to be insufficiently robust. The Friedrichshafen FF44 was rebuilt from the pusher FF34 using the same wings and engine and retained the Marine Number, 117, that had been assigned to the FF34. Like the FF34, the FF44 was built as a class CHFT.
The FF44 followed typical Friedrichshafen design practice except for its vertical tail surfaces, which featured a balanced rudder without fixed fin, a feature shared with some FF33L aircraft.
To improve propeller efficiency, the FF44 was designed with a reduction gear to reduce propeller speed. The large, slow-turning propeller was expected to improve performance. The FF44 was delivered on 24 October 1917, and this prolonged interval after return of the FF34 was likely due to difficulty getting the propeller reduction gears for the powerful Maybach engine. However, the FF44 did not demonstrate the performance improvement expected and it was cancelled on 31 March 1918, after a single prototype was built.
Friedrichshafen built three two-seat reconnaissance floatplane designs powered by a single 240 hp Maybach Mb.IV, the FF34 pusher, the FF40 with engine in the fuselage driving two propellers via bevel gears and shafts, and the FF44 of conventional configuration with reduction gear. These prototypes were likely built to evaluate and compare these different configurations.
All production Friedrichshafen reconnaissance floatplanes had the conventional configuration of the FF44, clearly indicating its superiority, but no production Friedrichshafen used the 240 hp Maybach. Instead, the much more readily available and significantly more reliable Benz engines, first of 150 hp and later of 200 hp, were used.
Friedrichshafen FF44 Specifications
Engine: 240 hp Maybach Mb.IV
Wing: Span Upper 18.40 m
Span Lower 16.80 m
Area 68.5 m2
General: Length 10.85 m
Height 4.25 m
Empty Weight 1,552 kg
Loaded Weight 2,305 kg
Maximum Speed: 145 km/h
Range: 600 km
Climb': 500 m 6.8 min
1,000 m 8.9 min
2,000 m 22.1 min
Flight, October 23, 1919.
SOME FRIEDRICHSHAFEN "MILESTONES"
"The F.F. 44
(Fig. 26) was an experimental machine, fitted with a 240 h.p. Maybach engine, driving the screw through reduction gearing."