De Havilland DH.9

As a successor to the successful DH.4, Geoffrey de Havilland designed a biplane, the DH.9, at Airco in 1916, which was subsequently used as a bomber during World War I. Unfortunately, it was not a successful aircraft, although as many as 4,000 were built in total. After the war, several bombers are rebuilt for use in civil aviation. Space is created in front and behind the pilot for two passengers and mail, and the type designation is changed to DH.9B. The passengers sit in an open cabin and are therefore issued thick leather jackets, flight caps, gloves and aviator goggles before departure.

One of the companies that will fly the DH.9 is England's Aircraft Transport and Travel (AT&T). Beginning in May 1920, AT&T operates flights for KLM between London and Amsterdam. At the end of 1920, KLM itself purchased DH.9s with which to fly to London in over 2 hours starting in 1921. KLM's first two DH.9s were given the registrations H-NABP and H-NABO, followed later in 1921 by H-NABE and H-NABF. The DH.9s are in service from 1921 to 1924 and make a total of 450 flying hours during this period.