May 27, Swiss professor Auguste Piccard and his assistant Kipfer take a stratosphere-balloon to 15,781 m, starting in Augsburg and landing on a glacier in Austria.
June
June 11 - The 40 passenger Handley Page HP-42 four-engine biplane enters service with British airline Imperial Airways, setting new standards of passenger service and comfort.
October 1 - KLM begins a regular service between Amsterdam and Batavia by Fokker F.XII. At 13,744 km (8,540 miles) this is the longest regular air route in the world at the time.