Pfalz E.I/E.II/E.IV/E.V/E.VI

 

The Pfalz E series were a development from the French Morane-Saulnier G and H of which Pfalz obtained a production license just before the outbreak of World War 1. The Fokker monoplanes (Fokker E series) which actually entered service months before the Pfalz Es, outperformed them in climb rate, maneuverability and handling characteristics. Therefore, the Fokkers were preferred over the Pfalzs. Fokker was accused of simply copying the French design, but taking into account that Fokker's designs were superior to those of Pflaz's the statement can't be true. Both monoplanes looked similar, yes, but designs were significantly different in detail. As both monoplanes looked similar, Allied pilots referred them both as just Fokkers.

The E-Type was divided into various variants:

• Pfalz E.I: The Pfalz E.I was created by mounting a synchronized Spandau LMG on a Pfalz-built Morane-Saulnier H (which although it was a license-built version, it wasn't completely identical to the French machine). It was powered by an 80 hp Oberursel U.0 engine. Only 45 aircraft were made and they arrived too late to make any significant impact in the war, therefore most of them were assigned to training and flying school units, specially in Bavaria.
• Pfalz E.II: This variant was a slightly enlarged version of the E.I, powered by a more powerful 9-cylinder Oberursel U.1 engine which yielded 100 hp of power. Wingspan was enlarged too, in order to provide more lifting power for the heavier engine. The wing was also braced by three flying wires, instead of two like the E.I. The fuselage was also enlarged to balance the heavier engine. Performance was better than the E.I as it was faster and had better climb rate and 130 were manufactured. 
  One E.II was offered to the Austo-Hungarian Navy by the financer Camillo Castiglioni in 1916. It was tested from 17th August 1916 until it crashed on 1st March 1917 during landing in Fazana. As we could only find text references to this machine, the drawing should be considered as speculative.
• Pfalz E.IV: This variant was powered by the 14-cylinder Oberursel U.III engine which yielded 160 hp of power. This rotary engine had a double row of cylinders and was much heavier than the preceding ones. As a development of the E.II as it was, the E.IV had the same wing but a slightly longer fuselage to balance the heavier engine. Thanks to its engine, its performance improved drastically, when compared to the E.II, even with two machine guns mounted. However, the Oberursel U.III engine had cooling problems with its second row of cylinders and wasn't as reliable as the previous ones. A total of 46 machines were built, but only five reached the frontlines at its peak number in April 1916, indicating that the type was outdated and saw barely any action.
• Pfalz E.V: The Pfalz E.V was powered by a 100 hp Mercedes D.1 inline six-cylinder engine, cooled by a nose-mounted, automobile-type radiator, giving it a distinctive appearance. It was based on the E.IV airframe and was faster in spite of its less powerful engine. However, the pre-war original Morane-Saulnier design wasn't capable of further development and was already obsolete by July 1916 when the prototype was tested. Furthermore, to compensate for the extra weight of the liquid-cooled engine, it was armed with a single machine gun. By July 1916 the Halberstadt D.II were already operating in the frontlines and their performance was superior and, therefore, only 20 machines were built, basically to keep Pfalz's factory active. A maximum of three were recorded to be at the frontlines in June 1916 and of those three, two were later transferred to the Imperial German Navy.
• Pfalz E.VI: This was the final variant of the Pfalz E-Types. It was basically an E.II powered by the same Oberursel engine, but having a different rudder shape and two sets of bracing wires, instead of the three employed in the E.II. It was tested also in July 1916 and a total of 20 machines were completed to keep Pfalz's factory active. They were used for training because they were obsolete for combat and none was recorded in the frontlines.

As the Fokker and other types were superior, only few numbers of Pfalz E-Types fighters were admitted into service, and even fewer were sent to the frontlines, where they were generally unpopular among pilots. Their service lasted until August 1916 when they were ordered to be retired from service and be cannibalized for spare parts, after many fatal crashes. Around 100 Pfalz E-Types were destroyed and the production stopped. Therefore, as Pfalz lacked a suitable replacement, Pfalz was assigned with the production of LFG-Roland biplane fighters.

Sources:

1. Flying Machines Press -  Pfalz Aircraft of World War I

2. http://www.theaerodrome.com/forum/showthread.php?t=20866

3. https://en.wikipedia.org/wiki/Morane-Saulnier_H