1909, the world's first airline was founded in Frankfurt am Main: The Deutsche Luftschiffahrts-Aktiengesellschaft (DELAG). DELAG then built the first airport in Frankfurt, called Airship Base at Rebstock, which was located in Bockenheim in the western part of the city and was primarily used for airships in the beginning. It opened in 1912 and was extended after World War I, but in 1924, an expert's report already questioned the possibility of further expansions at this location. With the foundation of Deutsche Luft Hansa in 1926, a rapid boom of civilian air travel started, and soon the airship base became too small to handle the demand. Plans for a new and larger airport located in the Frankfurt City Forest south-west of Schwanheim were approved in 1930 but were not realized due to the Great Depression. After the Machtergreifung in 1933, the government revived the plans and started the construction of the new airport. Second airport A two-storey station building with a six-storey tower originated in 1935 on the northern part of the airport, as well as other operating and outbuildings for maintenance and storage of aircraft. The approximately 100 hectares runway received a grass cover. The official opening of the new Flug- und Luftschiffhafen Rhein-Main took place on 8 July 1936. The first plane that landed was a Ju 52/3m. Six days later, on 14 July 1936, LZ 127 Graf Zeppelin landed at the airport. In 1936, 800 tons of cargo and 58,000 passengers were transported, and in 1937 these figures increased to 70,000 passengers and 966 tons of cargo. In the coming years, the new airport was the home base for the two largest German airships, LZ 127 Graf Zeppelin and LZ 129 Hindenburg. In 1938, Frankfurt was a central distribution point for the transport of airmail to North America. On 6 May 1937, the Hindenburg, flying from Frankfurt to New York, exploded shortly before it was scheduled to dock at Lakehurst. 36 people died. The accident marked the end of scheduled airship traffic and the end of the airship era. World War II After the beginning of World War II in 1939, all foreign airlines left the airport, and control of air traffic was transferred to the Luftwaffe. The airships were dismantled and their huge hangars demolished on 6 May 1940 during conversion of the base to military use. Luftwaffe engineers subsequently extended the single runway, and erected hangars