By the end of World War I, V12s were well established in aviation, powering some of the newest and largest fighters and bombers and being produced by companies such as Renault and Sunbeam. Many Zeppelins had 12-cylinder engines from German manufacturers Maybach and Daimler. Austro Daimler of the Austro-Hungarian empire, produced also V12, designed by Ferdinand Porsche, with first 300 and later 345 hp, used with the big flying boats of the A-H Naval Air force.