Albatros D.IV

The Albatros D.IV was a German single‑seat fighter developed by the Albatros Flugzeugwerke in early 1916 as a minor evolution of the successful D.III. Its design retained the D.III’s characteristic sesquiplane wing layout but incorporated a strengthened lower wing spars and a revised aileron system to improve structural integrity after the D.III’s notorious wing failures. Powered by the 180 hp (134 kW) Mercedes D.IIIa inline engine, the D.IV could reach a top speed of about 175 km/h (109 mph) and offered a climb rate comparable to contemporary Allied aircraft. Armament consisted of two synchronized 7.92 mm LMG 08/15 machine guns, the standard for German front‑line fighters. Only a handful of D.IVs were built; most were quickly converted back to D.III standard or abandoned in favor of the newer D.V series. Nevertheless, the D.IV played a pivotal role in highlighting the weaknesses of the sesquiplane concept, prompting Albatros engineers to reinforce wing structures and adopt a full‑span lower wing for later models. Its brief service illustrated the rapid pace of aviation development during World War I and contributed to the evolution of German fighter design. Today, very few examples survive, making the D.IV a rare collector's interest for aviation historians.