O.Thetford, P.Gray German Aircraft of the First World War (Putnam)
L.F.G. Roland D XIII
Next in the long series of Roland prototypes was the D XIII serialled 3002/18, there being no record of D X, XI or XII. This was little more than the second version of the D VII with a 195 h.p. Korting vee-eight engine with reduction gearing. Span, 9 0 m. (29 ft. 6 3/8 in.). Area, 23 sq.m. (248 sq.ft.). Armament, twin Spandau machine-guns.
L.F.G. Roland D XV (first version)
As the first of four D XV prototypes, No. 3004/18 still perpetuated the use of clinker-built fuselage first used on the D IV. The wings had no bracing cables and considerably more stagger than any of the previous prototypes which probably improved forward and downward visibility from the cockpit, but omission of centre-section cut-out could not have given very good upward and forward field of view. Engine, 160 h.p. Mercedes D III. Span, 8.64 m. (28 ft. 4 1/4 in.). Area, 23.8 sq.m. (257 sq.ft.). Weights: Empty, 730 kg. (1,606 lb.). Loaded, 910 kg. (2,002 lb.). Armament, twin Spandau machine-guns.
L.F.G. Roland D XV (second version)
The second D XV prototype. No. 3006/18, was basically a D VI airframe with a new wing cellule braced solely with single I-struts, no cables being used. The top wing was of greater chord while the chord of the lower wing was considerably reduced. This was the last of the Roland fighter series to feature the clinker-planked fuselage. Engine, 180 h.p. Mercedes D IIIa. Span, 9.0 m. (29 ft. 6 3/8 in.). Area, 23 sq.m. (248 sq.ft.). Armament, twin Spandau machine-guns.
L.F.G. Roland D XV (third version)
The third and fourth versions of the D XV were alike except for engine installation. In construction they were very different to their precursors, slab-sided plywood-covered fuselages being used and the wings braced with tubular steel "N" struts. There were no flying or landing wires bracing the wing cellule. This model is said to have been a copy of the Fokker D VII, which may or may not be true. Certainly it was no slavish although a certain similarity of outline must be admitted. Engine, 185 h.p. B.M.W. III (third version), 200 h.p. Benz Bz IIIa V (fourth version). Armament, twin Spandau machine-guns.
W.Green, G.Swanborough The Complete Book of Fighters
LFG ROLAND D XIII Germany
In March 1918, after the experimental 195 hp Korting Kg III eight-cylinder water-cooled Vee-type engine had completed a 24-hour duration test, an example of this power plant fitted with reduction gear was delivered to the Luft-Fahrzeug Gesellschaft for installation in the prototype of a new single-seat fighter, the D XIII. Based on the D VII and ordered in April 1918, the D XIII entered flight test in May 1918, but crankshaft cooling proved inadequate and difficulties were experienced with the oil system. In July, the Kg III engine was removed from the prototype and returned to the manufacturer for modification. It was destined not to be re-installed, however, as the D XIII was one of 10 prototypes destroyed in a hangar fire on 25 July 1918. The D XIII was fitted with two synchronised LMG 08/15 machine guns. No performance data were recorded.
Span, 29 ft 6 1/3 in (9,00 m).
Wing area, 247.58 sq ft (23,00 m2).
LFG ROLAND D XV Germany
Three prototypes of the D XV were ordered in April 1918, the original intention being to fit each aircraft with a different engine for comparison purposes. The D XV perpetuated the use of the Klinkerrumpf (clinker-built) fuselage first used on the D IV. The wing cellule was of the "wireless” type, having no bracing cables, and featured appreciably more stagger than that of any preceding LFG fighter. The first D XV was powered by a 160 hp Mercedes D IIIa engine and was completed before the end of April, but flight testing was interrupted in May by the decision to return the prototype to the factory for modifications. A second, similarly-powered, D XV appeared in June 1918, the principal changes being replacement of the paired interplane struts by single I-type struts and the introduction of overhanging ailerons on the upper wing. This prototype was flight tested with both the Mercedes engine and a 185 hp BMW IIIa, demonstrating a good turn of speed, but proving deficient in climb rate. In September 1918, Idflieg demanded further modifications in the light of the trials conducted with the first two prototypes. Instead, the LFG designed a completely new fighter which retained the D XV designation. The following data relate to the initial version of the D XV with the Mercedes D IIIa engine.
Empty weight, 1,609 lb (730 kg).
Loaded weight, 2,006 lb (910 kg).
Span, 28 ft 4 1/8 in (8,64 m).
Wing area, 256.19 sqft (23,80 m2).
LFG ROLAND D XV (II) Germany
Rather than introduce the modifications in the D XV demanded by Idflieg, LFG produced an entirely new fighter bearing no relationship to its predecessor, but, nevertheless, retaining the D XV designation. Bearing a strong similarity to the Fokker D VII and claimed by some to be no more than an unauthorised copy of that fighter, the new D XV was of different construction. The clinker-built fuselage gave place to one of rectangular cross section with plywood skinning, tubular steel N-type interplane bracing struts were employed and two prototypes were built. The first of these appeared late in October 1918 with a 185 hp BMW IIIa engine, and the second was rolled out shortly afterwards with a 200 hp Benz Bz nia. Neither prototype participated in the 3rd D-type contest, and further development was halted by the Armistice. No data relating to the second D XV design are available.