O.Thetford, P.Gray German Aircraft of the First World War (Putnam)

Brandenburg W 25
   Further development of K.D.W. single-seat seaplane with normal interplane bracing. Only one example was constructed, No. 2258, first with ailerons on top wing only, later (as illustrated) with ailerons at all wingtips connected by a link strut. Engine, 150 h.p. Benz Bz III. Span, 10.4 m. (34 ft. 1 1/2 in.). Length, 8.8 m. (28 ft. 10 1/2 in.). Height, 3.45 m. (11 ft. 3 7/8 in.). Area, 36.53 sq.m. (395 sq.ft.). Weights: Empty, 918 kg. (2,221 lb.). Loaded, 1,182 kg. (2,600 lb.). Speed, 160 km.hr (100 m.p.h.). Climb, 1,000 m. (3,280 ft.) in 6 1/2 min. Duration, 2 1/2 hr. Armament, two Spandau machine-guns.

W.Green, G.Swanborough The Complete Book of Fighters

BRANDENBURG W 25 Germany

   The last of the Heinkel-designed single-seat fighter float seaplanes built by the Hansa- und Brandenburgische Flugzeug-Werke, the W 25, produced as a single prototype late in 1917, was the final development of the KDW. Reverting to the 150 hp Benz Bz III engine used by the prototype and pre-production KDWs, the W 25 possessed an essentially similar fuselage, but discarded the "star" interplane strut arrangement in favour of normal strut bracing. Initially the prototype flew with ailerons on the upper wing only, but these were subsequently added to the lower wing, each pair being joined at the wingtip by link struts. Armament comprised two synchronised 7,92-mm LMG 08/15 machine guns. Having by this time lost interest in single-seat fighter floatplanes, the German Navy did not foster further development of the W 25.

Max speed, 99 mph (160 km/h).
Time to 3,280 ft (1 000 m), 6.5 min.
Empty weight, 2,024 lb (918 kg).
Loaded weight, 2,606 lb (1182 kg).
Span, 34 ft 1 1/2 in (10,40 m).
Length, 28 ft 10 1/2 in (8,80 m).
Height, 11 ft 3 7/8 in (3,45 m).
Wing area, 393.22 sq ft (36,53 m2).

C.Owers Hansa-Brandenburg Aircraft of WWI Vol.2: Biplane Seaplanes (A Centennial Perspective on Great War Airplanes 18)

Brandenburg W.25
  
   Another attempt to find a replacement to the KDW, the W.25 was an elegant single seat fighter floatplane in Class C2MG. Unusually only a single example, MN 2258, of the 150-hp Benz Bz.III powered fighter was constructed. The reason may have been that the Navy was now interested in two-seat fighters. The W.25 had conventionally braced wings of equal span and chord initially with ailerons only on the upper wing. Manoeuvrability must have been unsatisfactory as the machine was modified with ailerons, connected by a link strut, on both wings. It was retested in this form and this is how it was illustrated in the Atlas. Armament was a pair of synchronised Maxim 08/15 machine guns. The SVK tested the machine in February 1918. Nothing further is known of this machine which must have tested as unsatisfactory, however one source indicates that it was fitted with a 160-hp Maybach engine and used as a school machine. It was recorded at the Hage Repair Depot in November 1918.


Brandenburg W.25 Specifications
Source Typenschau Gray & Thetford Brandenburg 3-View SVK MN 2258
Span, m 10.40/10.40 10.4 10.400/10.400 10.400/10.400
Chord, m 1.80 - 1.800 1.800
Length, m 8.80 8.8 8.791 8.800
Height, m - 3.45 - 3.450
Areas, m2
Wings 30.53 36.53 36.118 30.53
Ailerons 1.80 - 4x0.85 1.80
Elevators 1.20 - 1.3 1.20
Rudder 0.55 - 0.47 0.55
Empty Wt, kg 912 918 840 912
Loaded Wt, kg 1,182 1,182 1,160 1,182
Performance
Speed in km/hr 160 160 16 160
Time to 800 m 4.7 minutes - - 4.7 minutes
Time to 1000 m 6.5 minutes 6.5 minutes - 6.5 minutes
Endurance - 2.5 hours - -
Engine - - 150-hp Benz 150-hp Benz

J.Herris German Seaplane Fighters of WWI (A Centennial Perspective on Great War Airplanes 2)

Brandenburg W25

   The final Brandenburg single-seat floatplane fighter design was the W25, a development of the KDW with conventional wing bracing. The W25, with its revised wing bracing, ailerons on all four wings, and increased wing span and area, was clearly an attempt to improve on the maneuverability, flight characteristics, and field of view of the KDW. Weight
was reduced slightly due to replacement of the star struts, but with the same 150 hp Benz Bz.III engine and the larger wing with its greater drag, both speed and climb rate were actually less than the KDW. Due to its inferior performance compared to the KDW only a single aircraft, Marine Number 2258, was produced.