![](https://random-writings.com/WordPress/wp-content/uploads/2021/02/k31_junkers_d1.jpg)
An indication of how quickly aircraft design evolved during the four years of war can be gained by comparing the previous photo to this all-metal Junkers D1 monoplane developed late in the war. (Wikimedia Commons https://commons.wikimedia.org/wiki/File:Junkers_D.I_fighter_in_1918.jpg)