Friedrichshafen FF.35

FF.35
	The FF.35 with axles installed underneath its floats
Role	Floatplane torpedo bomber
Manufacturer	Flugzeugbau Friedrichshafen
First flight	1916
Primary user	Imperial German Navy
Number built	1
Developed into	Friedrichshafen FF.41

The Friedrichshafen FF.35 was a German three-seat

Friedrichshafen Flugzeugbau built for the Imperial German Navy's (Kaiserliche Marine) Naval Air Service (Marine-Fliegerabteilung). Only one prototype was constructed in 1916 and it saw limited operational use during the war in Courland

.

Development

After the

airstrip with such a large weight of explosives. At the beginning of 1915 the Naval Office ordered the development of seaplanes capable of carrying torpedoes and the Seaplane Experimental Command (Seeflugzeug-Versuchs-Kommando (SVK)) issued requirements for these aircraft. They had to be twin-engine airplanes armed with a machine gun for self-defense and with a crew of two or three men: a pilot and observer for torpedo missions and a pilot, bombardier and gunner for bombing missions.^[1]

Friedrichshafen's submission was similar in general design to their

kW) Mercedes D.III straight-six engines were positioned between the wings in pusher configuration with the two-blade propellers behind the engines and the radiators at the front. The engines were supported by a pair of struts in an inverted V configuration.^[2]

The torpedoes used by the FF.35 and other German torpedo bombers were not designed for aerial use and had very narrow parameters for a successful launch, namely that the aircraft had to be flying straight and level and at an altitude of no more than 10 meters (33 ft). To give pilots a method by which all of these conditions could be judged, the aircraft were fitted with an

electrical circuit.^[3]

Operational history

The SVK placed an order for one prototype in February 1915,[Note 1] but construction was significantly delayed by Friedrichshafen's existing commitments and did not begin until 2 February 1916. It was delivered to the SVK in May for testing which was completed on 24 May and the aircraft received the serial number (Marine-nummer) 300.^{[Note 2]} The performance of the FF.35 was deemed satisfactory, but it was structurally obsolete by the time it was delivered. Although no further examples were built, the FF.35 formed the basis for the more successful and streamlined FF.41.^[6]

The Naval Air Service began flying bombing missions with the FF.35 from the

Naval Air Station (Seeflugstation) at Engure, Latvia, (Angern, Courland) on the western shore of the Gulf of Riga before the end of May. The floatplane also was extensively used by the SVK for trials; the last reference to it is from September when it was noted as being equipped with a radio and a machine gun.^[7]

Specifications

Data from Flugzeugbau Friedrichshafen GmbH: Diplom-Ingenieur Theodor Kober;[8] Friedrichshafen Aircraft of WWI: A Centennial Perspective on Great War Airplanes^[5]

General characteristics

Crew: 3
Length: 13.5 m (44 ft 3 in)
Upper wingspan: 23.74 m (77 ft 11 in)
Lower wingspan: 21.02 m (69 ft 0 in)
Height: 4.5 m (14 ft 9 in)
Wing area: 100 m² (1,100 sq ft)
Empty weight: 2,292 kg (5,053 lb)
Gross weight: 3,543 kg (7,811 lb)
Powerplant: 2 × Mercedes D.III water-cooled straight-six engines, 120 kW (160 hp) Originally measured as 160 PS each
Propellers: 2-bladed pusher propellers

Performance

Maximum speed: 114 km/h (71 mph, 62 kn)
Range: 770 km (480 mi, 420 nmi)

Armament

Guns: 1 or 2 × 7.92 mm (0.312 in)
Parabellum MG14
machine-guns
Bombs: 1 × 726 kg (1,601 lb) torpedo

Notes

^ Aviation historian Siegfried Borzutzki claims that the aircraft was ordered on 24 March.^[4]
^ Some sources say that another aircraft was built with Marine-nummer 310, but aviation historian Jack Herris states that SVK records show that the entire block of 301–400 numbers was never used.^[5]

Footnotes

^ Schmeelke, pp. 3, 10, 21
^ Herris, pp. 186–187
^ Schmeelke, p. 10
^ Borzutzki, p. 51
^ ^a ^b Herris, p. 187
^ Herris, p. 186
^ Schmeelke, p. 22
^ Borzutzki, pp. 119–120

Bibliography

Borzutzki, Siegfried (1993). Flugzeugbau Friedrichshafen GmbH: Diplom-Ingenieur Theodor Kober [Friedrichshafen Aircraft Company: Diploma-Engineer Theodore Kober] (in German). Berlin: Burbach.
ISBN 3-927513-60-1
.

Herris, Jack (2016). Friedrichshafen Aircraft of WWI: A Centennial Perspective on Great War Airplanes. Great War Aviation Centennial Series. Vol. 21. n.p.: Aeronaut Books.
ISBN 978-1-935881-35-3
.

Schmeelke, Michael (2020). "Torpedo Los!": The German Imperial Torpedo-Flieger. n.p.: Aeronaut Books.
ISBN 978-1-953201-17-1
.

[5] Aviation historian Siegfried Borzutzki claims that the aircraft was ordered on 24 March.^[4]

[7] Some sources say that another aircraft was built with Marine-nummer 310, but aviation historian Jack Herris states that SVK records show that the entire block of 301–400 numbers was never used.^[5]

[1] Schmeelke, pp. 3, 10, 21

[2] Herris, pp. 186–187

[3] Schmeelke, p. 10

[4] Borzutzki, p. 51

[h2-6] Herris, p. 187

[8] Herris, p. 186

[9] Schmeelke, p. 22

[10] Borzutzki, pp. 119–120

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[Note 2]

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