. "1"^^ . "1915Z"^^ . "1915Z"^^ . "The Junkers J 1, nicknamed the Blechesel (\"Tin Donkey\" or \"Sheet Metal Donkey\"), was the world's first practical all-metal aircraft. Built early in World War I, when aircraft designers relied largely on fabric-covered wooden structures, braced with struts and exposed rigging lines, the Junkers J 1 was a revolutionary development in aircraft design, being built and flown only 12 years after the Wright Brothers had first flown the \"Flyer I\" biplane in December 1903."@en .