sentences:  De Havilland DH.50
  
  The de Havilland DH.50 was a 1920s British large single-engined biplane transport built by de Havilland at Stag Lane Aerodrome, Edgware, and licence-built in Australia, Belgium and Czechoslovakia.In the early 1920s, Geoffrey de Havilland realised that war surplus aircraft would need replacing, so his company designed a four-passenger-cabin biplane, the "DH.50", using experience gained with the earlier de Havilland DH.9.