 Complete the following phrase:  LZ 129 Hindenburg ; Registration: D-LZ 129 was a German commercial passenger-carrying rigid airship, the lead ship of the Hindenburg class, the longest class of flying machine and the largest airship by envelope volume. She was designed and built by the Zeppelin Company Luftschiffbau Zeppelin GmbH on the shores of Lake Constance in Friedrichshafen, Germany, and was operated by the German Zeppelin Airline Company Deutsche Zeppelin-Reederei. The airship flew from March 1936 until it was 