This aircraft was a biplane version of the E V monoplane. It was to the Walfisch format, with deep gap-filling fuselage and car-type radiator at the nose. Although not confirmed, the engine is thought to have been 100 h.p. Mercedes D I.
The Pfalz D 4 was the first biplane fighter design from Pfalz. With a fuselage resembling the earlier Pfalz E.V, the D 4 was powered by a 150 hp Benz Bz.III engine. The cutouts in the sides of the cockpit gave the pilot better visibility downwards to the front.
The Pfalz D 4 version without fixed fin or headrest is shown here. The exhaust pipe was also longer than that of the version with fixed fin and headrest. Iron crosses are painted on both sides of the elevators like Pfalz E-types.
All Aero 