In late 1916, the demand for a durable observation aircraft capable of performing ground attack missions led to the introduction of the Junkers J.I. Developed in early 1917, it was the world's first all-metal aircraft produced in quantity. Eliminating the need for external bracing wires, the fuselage, wings and tail were constructed of Duralumin while the engine and two-man crew were protected by a nose-capsule of 5-mm chrome-nickel sheet-steel. Although this unique design resulted in a strong and durable aircraft capable of surviving the effects of enemy ground fire, the Junkers J.I was heavy, cumbersome and took forever to get off the ground.