Pfalz – Fighter Aircraft from Rheinland the Wine Country


In the summer of 1916, the Pfalz works began working on their D-type aircraft. The design bore resemblance to the Pfalz E – a wooden truss fuselage with a square cross-section and a top wing based on the Roland D.I, attached to the fuselage. The Pfalz D.4 was powered by a water-cooled 110kW (150hp) Benz Bz.III in-line engine. The engine was entirely encased and featured a front car-type radiator. The fuselage and top wing had cut outs to improve visibility. The vertical tail unit comprised a triangular stabilizer and a trapezium-shaped rudder with two rounded tips. The aircraft was armed with twin machine guns entirely covered by the engine cowling. Flight tests were conducted in the summer of 1916. The fighter’s performance was much worse than that of the Halberstadt and Albatros aircraft. It was not mass produced. One of the most interesting designs was created by the L.F.G Roland works. It was the Roland D.I with a wooden, semi-monocoque fuselage structure typical for the company.
The L.F.G. factory burned down on September 6, 1916. The fire was allegedly started by the British intelligence. A new factory was built in Charlottenburg. To maintain aircraft production and to save the collapsing15 Pfalz works, the Idflieg ordered 20 Roland D.I aircraft to be built in the Pfalz Flugzeugwerke.
The machines received military numbers 1680–1699/16. To produce the Rolands the company adopted the WICKELRUMPF semi-monocoque technique which became a standard for the Pfalz factory. In September 1916 they began making aircraft under designation Pfalz D.I or Roland16 D.I (Pfal). The aircraft was powered by a six-cylinder, water-cooled, 118kW (160hp) Mercedes D.III in-line engine and reached speeds up to 180km/h.
The Roland D.I had the same disadvantage as the Roland C.II – poor forward and downward visibility that made dogfights and landings difficult. The flaw was remedied and the Roland D.II created. To improve visibility, the top wing attachment point was rebuilt, its thickness was reduced by 10cm. The design also featured radiators installed in the upper wing and a lowered pilot’s seat. Tests were successfully concluded in October 1916 and the Pfalz works received an order for 100 Roland D.II aircraft. The machines received numbers 2830–2929/16. They were built under the initial designation Pflaz D.II (Roland D.II [Pfal]). During the production process, the Mercedes17 was replaced by a 132kW (180hp) Argus AS.III engine. The aircraft powered by that engine was designated Pfalz D.IIa. The the Pfalz works received the Idflieg order for further 100 planes with numbers 300–399/17. Initially they were designated Pfalz D.IIa which was later changed to Roland D.IIa (Pfal).

Pipe radiator of the Pfalz D.XII. [Krzyżan’s collection]


The Pfalz company launched production of another Roland version. It was the Roland D.III with the upper wing placed above the fuselage which greatly improved forward visibility. The Idflieg ordered 100 new machines under designation Roland D.III (Pfal). Only 30 fuselages had been built before the production was cancelled. The construction was a great lesson for the designers and workers of the Speyr factory.
Soon a new French fighter aircraft appeared over the front at Verdun. The Nieuport 11C1 and later the Nieuport 16C1 and 17C1 proved superior to the Fokker and Pfalz monoplanes and the D-type18 biplanes which were less manoeuvrable. Captured Nieuports were thoroughly tested by the Idflieg specialists. They became obsessed with the Nieuport which resulted in an order for an aircraft of a similar sesquiplane design. Some of the German aviation producers like Euler and Siemens Schuckert chose the easy way and presented copies of the Nieuport as their own designs. The Albatros and Pfalz prepared their original constructions.

Pfalz D.III – brain child of the Gehringer – Paulus – Golmacher team
At the beginning of 1917, the Pfalz company employed engineer Rudolf Gehringer who had been working under supervision of engineer Theodor Kober at the Friedrichshafen Flugzeugbau works. He became the chief constructor and remained in the position until the end of the war. His closest co-workers were engineers Paulus and Goldmacher. A captured Nieuport was delivered to Speyr. It was thoroughly tested and measured. Following the Idflieg requirements, the team began working on a new fighter aircraft in the sesquiplane configuration. With a perfect semi-monocoque fuselage already designed, the constructors decided to use that kind of structure in a new aircraft. It was powered by the 118kW (160hp) Mercedes D.III engine. Wooden, two-spar wings were connected by U-shaped struts that made the construction resistant to the flutter effect that plagued the Nieuports and Albatros D.III and D.V fighters. The armament consisting of two Spandau LMG 08/15 machine guns was installed in the fuselage to limit drag. The semi-monocoque (wickelrumpf) fuselage structure demanded huge efforts which significantly extended19 the construction time. First, two halves of the fuselage were formed with stripes of plywood glued around a mold – 1mm thick and 9cm wide veneer was placed obliquely to the axis of symmetry at 45° angle. The next layer was laid in the opposite direction. Attachment points were strengthened with fabric stripes.

Pfalz D.III side and front view, drawing from the spare part catalogue. [Factory drawing]

The construction used cold glue technique. Both halves were attached to a light wooden structure made of frames and longerons. A wooden engine mount was in the front section of the fuselage. The whole structure was thoroughly polished and covered with fabric. The vertical stabilizer was an integral part of the fuselage similarly to the lower wing attachment points. The fuselage shape was very aerodynamic and the engine, protruding forward, was covered with aluminum fairing. The trapezoid-shaped, two-spar upper and lower wings were made of wood. The upper wing was attached to the fuselage with an inverted U-shaped strut. The lower wing was attached with special braces. The wing cellule was stiffened by steel wires. The upper wing housed a Teves und Brown radiator with manually operated shutters and an auxiliary header fuel tank. The wooden horizontal stabilizer was an inverted airfoil section that made it easier to recover from a dive. The elevator and rudder had a metal structure covered with fabric. The rudder of the prototype aircraft was a slightly rounded rhomboid and was unbalanced. The wooden unbalanced ailerons were installed only in the upper wing. The classical two-leg undercarriage and the wooden tail skid had rubber wire shock absorbers.

PFALZ D-III (4004/17): Flown by Obltn. Rudolf Berthold, Staffelfuhrer Jagdstaffel 18; Harlebeke, Belgium; October 1817. [Paintings by Ronny Bar]

The aircraft was test flown in the spring of 1917 and after minor corrections presented to the Idflieg. Its performance was similar to the Albatros D.III and, as it later turned out, was not subject to the flutter effect of the lower wing. In April 1917 the Idflieg, or Flugzeugmeisterei der Inspektion der Fliegertruppen20, ordered 70 Pfalz D.III fighters and further 300 in June 1917 after the aircraft had successfully passed the Typenprüfung. The orders saved the factory from financial catastrophe. The first three Pfalz D.III aircraft were sent to Jasta 10 at the end of July and at the beginning of August 1918. Pilots who flew the fighter reported difficulties reaching guns in case of a jam. They also claimed that horizontal speed was lower than that of the Albatros D.III and D.V, however they liked the fighter’s performance in a dive that was superior to the Albatros. Visibility and climb rate was very good. The Pfalz was less manoeuvrable than the Albatros.  

PFALZ D-XII (1394/18)  Jagdstaffel 77b; Vouziers, France; August 1918. [Paintings by Ronny Bar]


In the autumn of 1917, Manfred von Richthofen wrote a letter to Anthony Fokker which contained features that should characterize a fighter aircraft: high horizontal speed, climb rate is not important, full throttle turn without altitude loss, high diving speed and easy recovery, machine guns placed together atop a fuselage at pilot’s eye level. The Pfalz D.III implemented only some of those features.
The construction team from Speyr experimented constantly to improve the aircraft’s performance. Trials included a 143kW (195hp) V-8 Benz Bz.IIIb engine and an eight-cylinder, 147kW (200hp) Adler Ad.IV. Lack of perspectives to acquire the engines made the constructors suspend the trials. It is highly probable that the aircraft were the Pfalz D.IV and Pfalz D.V, however it is difficult to find any information about them.
A D-type fighter, called “wireless” was also designed.[…]

 

 

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