The LVG D.IV was a somewhat unlucky fighter, suffered from two engine failures that destroyed the two prototypes, ending development of the type.
LVG had produced a series of experimental fighters. The LVG D 10 of 1916 had featured an unusual tall and narrow fuselage that filled the gap between widely separated wings. This was followed by the LVG D.II, which had a more conventionally sized fuselage, although with the wings still mounted directly onto it. The D.II suffered an accident during testing and was abandoned.
LVG then moved onto the D.III. This was a larger aircraft, with an aerodynamically clean plywood covered semi-monocoque fuselage, a gap between the fuselage and the upper wing, 'N' wing struts and semi-rigid wing bracing, using wire bracing for the flying wires but struts in place of the landing wires. Type testing of the D.III ended on 2 June 1917 and the Idflieg judged it to be too big and too heavy to be an effective fighter.
LVG moved onto the D.IV. This retained the aerodynamically clear plywood covered semi-monocoque fuselage, although the 195hp Benz Bz IIIb V-8 direct drive engine allowed for a cleaner nose than the NAG C III engine of the D.III. It retained the single axle main undercarriage of the D.III and had a similar tail structure.
The wings were similar to those used on the D.II. The D.IV was a single bay biplane with V struts between the wings. It used landing and flying wires. Both wings were straight edged and equal chord. The upper wing had straight edges, a wider span and wider chord, the lower wing had curved tips. The pilot's cockpit was below the rear half of the upper wing, with a curved cut-out for the pilot.
The D.IV was smaller and lighter than the D.III, with a reduction of nearly 5ft in wing span and 209lb in loaded weight. Unfortunately the top speed does not appear to have been recorded, but with less weight and a more powerful engine it would probably have been faster than the D.III.
Two prototypes of the D.IV were built, but it was an unlucky design. The first prototype was destroyed on 5 January 1918 when the crankshaft broke in flight, causing a fire. The second prototype made it to the first of the 'D-type' contests at Adlershof, but on 29 January the engine caught fire and the aircraft was destroyed. This ended development of the D.IV. LVG went on to produce two further fighter designs, the D.V and D.VI, but these were both new designs.
Engine: Benz Bz IIIb direct drive V-8
Span: 27ft 10.75in
Length: 20ft 7.25in
Height: 8ft 10.25in
Empty Weight: 1,496lb
Loaded Weight: 2,057lb
Climb rate: 28min to 16,400ft