Junkers J.I

The Junker J.I was a German two‑seat, all‑metal sesquiplane introduced late in World War I. Developed by the Junkers Motorenbau und Junkers Flugzeugwerk, it first flew in August 1916 and entered service with the Luftstreitkräfte in early 1917. Its most distinctive characteristic was the pioneering use of a corrugated duralumin skin, a structural technique invented by Hugo Junkers that gave the aircraft exceptional strength and rigidity while keeping weight low. The J.I featured a single Oberursel rotary engine of 110 hp, a forward‑facing crew compartment, and a rear gunner’s position protected by an armored hull. This layout made it one of the earliest armored ground‑attack planes, capable of low‑level reconnaissance, close‑support bombing, and strafing missions over the Western Front. Although only a few hundred were built before the Armistice, the J.I demonstrated the viability of metal construction and armor in combat aircraft. Its design directly influenced the later Junkers D‑1 and the all‑metal fighters of the interwar period, establishing a legacy that shaped modern military aviation. Pilots valued its robust construction and good visibility, and the armored cockpit protected crews from ground fire, influencing post‑war metal aircraft studies.

Junkers Motorenbau und Junkers Flugzeugwerk

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