 Many of these new routes had few facilities such as modern runways, and this era also became the age of the great flying boats such as the German Dornier Do X, American Sikorsky S-42 and British Short Empire, which could operate from any stretch of clear, calm water.This period also saw the growth of barnstorming and other aerobatic displays which produced a corps of skilled pilots who would contribute to military air forces during World War II on all sides of the conflict.Recreational gliding flourished, particularly in Germany through Rhön-Rossitten.