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

Pfalz Dr I
   This stocky triplane fighter stemmed from the D VII and in fact was virtually a D VII fitted with triplane wings. Official type test was in October 1917. Reports on the number of these triplanes built vary, but the most reliable figure seems to indicate that no more than ten were constructed. The performance did not offer sufficient improvement over that of the Fokker triplane. Engine, 160 h.p. Siemens-Halske Sh III. Span, 8.55 m. (28 ft. 0 5/8 in.). Length, 5.5 m. (18 ft. 0 5/8 in.). Height, 2.76 m. (9 ft. 0 5/8 in.). Area, 17.2 sq.m. (186 sq.ft.). Weights: Empty, 510 kg. (1,122 lb.). Loaded, 705 kg. (1,551 lb.). Climb, 1,000 m. (3,280 ft.) in 1.7 min., 3,000 m. (9,840 ft.) in 6.2 min. Armament, twin Spandau machine-guns.

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

PFALZ DR I Germany

   Official interest in the potential of the triplane configuration for single-seat fighters prompted Pfalz to develop the Dr I. Powered by a 160 hp Siemens Halske Sh III 11-cylinder geared rotary engine, this underwent Typen-Prufung in October 1917. Armed with twin synchronised LMG 08/15 guns, the Dr I was of sufficient promise to warrant a pre-series evaluation batch of 10 aircraft, all of which arrived at the Front by the end of April 1918. Service pilots considered the Dr I too slow and its Sh III engine insufficiently reliable for frontline use, and no further examples were produced.

Max speed, 118 mph (190 km/h) at 13,125 ft (4 000 m).
Time to 16,405 ft (5 000 m), 13.5 min.
Endurance, 1.5 hrs.
Empty weight, 1,124 lb (510 kg).
Loaded weight, 1,554 lb (705 kg).
Span, 28 ft 0 2/3 in (8,55 m).
Length, 18 ft 0 1/2 in (5,50 m).
Height, 9 ft 0 2/3 in (2,76 m).
Wing area, 185.14 sqft (17,20 m2).


PFALZ DR II Germany

   Developed in parallel with the Dr I, the Dr II was a smaller and lighter single-seat fighter triplane utilising the well-proven Oberursel Ur II rotary of 110 hp. A second prototype, the Dr IId, differed in having a 110 hp Siemens Halske Sh I rotary, but neither offered sufficient promise to warrant further development. The following data relate to the Ur II-powered aircraft.

Time to 9,840 ft (3 000 m), 10.2 min.
Endurance, 1.5 hrs.
Empty weight, 882 lb (400 kg).
Loaded weight, 1,314 lb (596 kg).
Span, 23 ft 7 1/2 in (7,20 m).
Length, 19 ft 6 1/4 in (5,95 m).
Height, 9 ft 6 1/8 in (2,90 m).

J.Herris Pfalz Aircraft of WWI (A Centennial Perspective on Great War Airplanes 5)

Pfalz Dr.I

   The first Pfalz fighter designed from the beginning as a triplane was the Dr.I. The attractive Dr.I, powered by the then experimental 160 hp Siemens-Halske Sh.III counter-rotary engine, was well streamlined and had few bracing wires. During flight trials in August 1917 the Pfalz Dr.I demonstrated the fastest climb rate of any German WWI aircraft. It reached 5,000 meters in 11.5 minutes compared to the 35 minutes required by the Albatros D.V, then the standard German fighter. This stunning result generated great interest in introducing the Dr.I into combat in quantity. However, the Sh.III engine was too unreliable at the time, so production was limited to an evaluation batch of 10 Pfalz Dr.Is which were produced and sent to the front in April 1918. Although the aircraft had flown months before, engine unreliability prevented earlier deliveries.
   The Pfalz Dr.I proved to have less maneuverability than the Fokker Dr.l and was too slow compared to contemporary biplane fighters. Its limited speed and engine development problems prevented mass production.

Pfalz Dr.I Specifications
Engine: 160 hp Siemens Sv Halske Sh.III
Wing: Span Upper 8.55 m
Span Middle 8.10 m
Span Lower 7.82 m
Chord Upper 1.10m
Chord Middle 0.50 m
Chord Lower 0.70 m
Gap upper 0.78 m
Gap lower 0.75 m
Stagger 0.70 m
Area 17 sq m
General: Length 5.50 m
Height 2.70 m
Empty Weight 510 kg
Loaded Weight 705 kg
Climb: 1000m 1.5 min
2000m 3.0 min
3000m 5.5 min
4000m 8.5 min
5000m 11.5 min
6000m 14.5 min


Pfalz Dr.II and Dr.IIa

   Encouraged to develop the triplane configuration with a combat-ready engine, Pfalz followed the Dr.I with the slightly smaller Dr.II fitted with the proven 110 hp Oberursel Ur.II and the Dr.IIa fitted with the 110 hp Siemens-Halske Sh.I, which was more reliable than its more powerful development. Using low-powered engines, neither the Dr.II nor Dr.IIa had sufficient performance to merit production.
   Although the Pfalz Dr.I, and its smaller derivatives the Dr.II and Dr.IIa, were not operational successes, the basic Dr.I design evolved into the Pfalz D.VII and D.VIII biplane fighters, both of which were placed into production.

Pfalz Dr.II & Dr.IIa Specifications
Engine: Dr.II - 110 hp Oberursel Ur.II
Dr.IIa - 110 hp Siemens-Halske Sh.I
Wing: Span Upper 7.20 m
Chord Upper 1.20 m
Chord Middle 0.50 m
Chord Lower 0.80 m
Gap Upper 0.82 m
Gap Lower 0.69 m
Stagger 0.73 m
General: Length 5.95 m
Dr.II: Empty Weight 400 kg
Loaded Weight 596 kg
Dr.IIa: Empty Weight 395 kg
Loaded Weight 568 kg
Climb: Dr.IIa: 1000m 3 min
2000m 6.5 min
3000m 10.2 min
4000m 14.4 min
5000m 19.4 min
6000m 28.9 min

P.Grosz, G.Haddow, P.Shiemer Austro-Hungarian Army Aircraft of World War One

Pfalz Dr.I

  In September 1917, the Pfalz Dr.I prototype triplane fighter clocked the fastest rate of climb ever recorded by a German aircraft. A pre-production batch of ten fighters was ordered for combat evaluation by the German air service. Based on the outcome, the LFT planned to assign the MAG company the license manufacture of the Pfalz Dr.I powered by a 145 hp Oberursel Ur.Ill rotary engine. The project was dropped when frontline experience in early 1918 showed that the Dr.I was structurally deficient, not to mention the unavailability of rotary-engine lubricant.

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The best-known of German triplanes after the Fokker Dr.I emerged from the Pfalz factory at Speyer on the Rhine. The design was of typical Pfalz construction; the Wickelrumpf or wrapped-skin fuselage structure was built up on a light framework of stringers by a series of thin three-ply strips and cloth tape. The result, as evidenced in the D.III, was strength but increased weight. The Dr.I was based on the Pfalz D.VII, a relatively unsuccessful product, and was compact and well-proportioned. Powered by a 160 hp Siemens Sh III engine, it began flight tests in August 1917 and recorded the best rate of climb of any German aircraft up to that time, superior to the Fokker Dr.I. Probably three prototypes were built, 3050 and 3051/17 with 3052/17 as a static test.
   On 12 December 1917 Manfred von Richthofen left his Geschwader to visit the Pfalz works, accompanied by his technical officer Lt Krefft. Such well-known pilots as Hpt Willy Meyer, von Tutschek and Ernst Schlegel also arrived to evaluate the new types. Von Richthofen was very impressed with the capabilities of the Dr I, and it is probable that as a result of his recommendations the Pfalz was ordered into small-scale production for front-line evaluation. It was further planned to build 100 Dr.I's, and to expose them all along the front simultaneously in January 1918, presumably with the purpose of demoralizing the enemy. This scheme was evidently dropped, for only ten were constructed. Nine went to the front, so presumably one Dr.I was retained at Speyer. Photographs exist of 221 and 222/17, but beyond that there is no record of other production examples or any service details of the nine that reached the front.
   The Pfalz Dr.I arrived too late to compete seriously with the Fokker Dr.I and its quicker production techniques. The official reason for its rejection was its slow speed, and indeed this would seem to have been its main disadvantage.
  
  
Description: Single seat fighter
Manufacturer: Pfalz Flugzeug-Werke, G.m.b.H. Speyer am Rhein (Pfal.)
Engine: 160 hp Siemens-Halske Sh. III
Dimensions:
   Span 8.6 m (28 ft. 1 in.)
   Length 5.6 m. (18 ft. 1 in.)
   Height 2.9 m. (9 ft. 1 in.)
   Area 17.2 sq m. (186 sq. ft.)
Weights:
   Empty 498 kg (1,122 lbs)
   Loaded 704 kg (1,551 lbs)
Performance:
   Climb to
   1,000 m 1 min 12 secs
   2,000 m 3 mins 12 secs
   3,000 m 5 mins 24 secs
   4,000 m 7 mins 48 secs
   5,000 m 10 mins 48 secs
   6,000 m 14 mins
   Ceiling 6,500 m ( 21,325 ft)
   Endurance 1 1/2 hrs
Armament: Twin Spandau machine-guns
Serials Prototypes: Dr 13050/17, 3051/17
Production: Dr 1221/17, 222/17. Five more examples built