Keywords: D-57 Airship Pony Blimp.lower view.jpg en D-57 Airship Pony Blimp lower view 1920 Maurer Maurer 1987 Aviation in the US Army 1919-1938 United States Air Force Historical Research Center Office of Air Force History United States Air Force Washington D C United States Air Force other versions PD-USGov Uploaded with UploadWizard D-57 Airship Pony |