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

L.V.G. D IV
   Continuing the streamlined, ply-covered fuselage trend, the L.V.G. D IV featured a wing cellule similar to that of the earlier D II, with single-spar lower wing and vee interplane struts. The nose, of blunter proportions but still neatly spinnered, housed the vee-eight type, direct-drive, 195 h.p. Benz Bz IIIb engine. The machine participated at the second D types Competition at Adlershof in June 1918. Span, 8.5 m. (27 ft. 10 3/4 in.). Length, 6.28 m. (20 ft. 7 1/4 in.). Height, 2.7 m. (8 ft. 10 1/4 in.). Area, 18.06 sq.m. (195 sq.ft.). Weights: Empty, 680 kg. (1,496 lb.). Loaded, 935 kg. (2,057 lb.). Climb, 5,000 m. (16,400 ft.) in 28 min. at loaded weight of 911 kg. (2,004 lb.).

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

LVG D IV Germany

   Retaining the aerodynamically clean, plywood-covered semi-monocoque fuselage style of the D III and a generally similar wing cellule, with single-spar lower wing and Vee-type interplane struts, the LVG D IV was in the final stages of assembly in September 1917, according to an Idflieg report. Serving as a test-bed for the new 185 hp Benz Bz IIIbo eight-cylinder Vee-type direct-drive engine, the D IV was flight tested intermittently until, on 5 January 1918, the crankshaft broke in flight. The aircraft caught fire and was destroyed. A second D IV prototype was completed in late January, but suffered recurrent engine problems. Nevertheless, it was entered in the 1st D-type contest at Adlershof, but on 29 January, the first day of the competition, the engine caught fire and the aircraft was destroyed, further development being discontinued.

Time to 16,405 ft (5 000 m), 28 min.
Empty weight, 1,499 lb (680 kg).
Loaded weight, 2,061 lb (935 kg).
Span, 27 ft 10 2/3 in (8,50 m).
Length, 20 ft 7 1/4 in (6,28 m).
Height, 8 ft 10 1/4 in (2,70 m).
Wing area, 194.4 sqft (18,06 m2).

J.Herris LVG Aircraft of WWI. Vol.3: Types C.VI-C.XI & Fighters (A Centennial Perspective on Great War Airplanes 36)

LVG D.IV

  The LVG D.IV prototype followed quickly on the D.III. Reported as nearing completion in September 1917 according to an Idflieg report, it was flying later in 1917. The Albatros and LVG main factories were next door to one another at Berlin-Johannisthal, separated only by an airship hangar, and the influence of the Albatros D.V on the LVG D.IV is apparent. Both types had similar wing structures with single-spar lower wings and V-struts, and the tailplanes were also similar. In fact, the LVG D.IV resembled a V-8 powered Albatros.
  The LVG D.IV served as a flying testbed for the experimental 185 hp Benz Bz.IIIb V-8 engine. During a test flight on 5 January 1918 the crankshaft broke in flight and the D.IV caught fire and was destroyed. Another D.IV was completed later that month but suffered continuing engine problems. Despite this it was entered in the first fighter competition at Adlershof. On 29 January 1918, the first day of the competition, the engine in the second prototype D.IV caught fire and this prototype was also destroyed. At that point there was no possibility of another D.IV prototype entering the competition and further D.IV development was abandoned.
  With the exception of the single-spar lower wing, the D.IV makes a good impression with its good streamlining and V-8 engine - which was still experimental itself and thus the Achilles Heel of the aircraft. One wonders why LVG would change to a single-spar lower wing despite widespread knowledge of the lower wing failures in the Albatros fighters with similar single-spar lower wings.


LVG Fighter Specifications
LVG D 10 LVG D.II LVG D.III LVG D.IV LVG D.V LVG D.VI
Engine 120 hp Mercedes D.II 160 hp Mercedes D.III 185 hp NAG C.III 195 hp Benz Bz.IIIb 195 hp Benz Bz.IIIb 195 hp Benz Bz.IIIb
Span, Upper - - 10.00 m 8.50 m - -
Wing Area - - 26.20 m2 18.06 m2 - -
Length - - 7.53 m 6.28 m - -
Empty Weight - - 773 kg 680 kg - -
Loaded Weight - - 1,028 kg 935 kg - -
Max. Speed - - 175 km/h - - -
Climb 5000 m - - 25 minutes 28 minutes - -

M.Dusing German Aviation Industry in WWI. Volume 1 (A Centennial Perspective on Great War Airplanes 84)

Luftverkehrsgesellschaft mbH, Berlin-Johannisthal, (LVG)

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  After these unsuccessful attempts, the company initially refrained from further in-house developments. LVG made successful efforts to obtain licenses from the Army Administration to build Albatros Alb D.II and DFW C.V aircraft.
  A machine with a 200 hp Benz Bz.IV engine designed during these license constructions, internally perceived as a Type D XIII, also led to no success.
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