Editing Morse code (section)

===Radiotelegraphy and aviation===
In the 1890s, Morse code began to be used extensively for early [[radio]] communication before it was possible to transmit voice. In the late 19th and early 20th&nbsp;centuries, most high-speed international communication used Morse code on telegraph lines, undersea cables, and radio circuits.

Although previous transmitters were bulky and the [[Spark-gap transmitter|spark gap system of transmission]] was dangerous and difficult to use, there had been some early attempts: In 1910, the U.S. Navy experimented with sending Morse from an airplane.<ref name=Howeth-1963/> However the first regular aviation radiotelegraphy was on [[airship]]s, which had space to accommodate the large, heavy radio equipment then in use. The same year, 1910, a radio on the airship [[America (airship)|''America'']] was instrumental in coordinating the rescue of its crew.<ref name=K2TQN-blog/>

During [[World War I|World War&nbsp;I]], [[Zeppelin|Zeppelin airships]] equipped with radio were used for bombing and naval scouting,<ref name=Pop-Sci-1918-04-Zeppelin/> and ground-based radio direction finders were used for airship navigation.<ref name=Pop-Sci-1918-04-Zeppelin/> Allied airships and military aircraft also made some use of radiotelegraphy.

However, there was little aeronautical radio in general use during [[World War I]], and in the 1920s, there was no radio system used by such important flights as that of [[Charles Lindbergh]] from [[New York City|New York]] to [[Paris]] in 1927. Once he and the ''[[Spirit of St. Louis]]'' were off the ground, Lindbergh was truly incommunicado and alone. Morse code in aviation began regular use in the mid-1920s. By 1928, when the first airplane flight was made by the [[Southern Cross (aircraft)|''Southern Cross'']] from California to Australia, one of its four crewmen was a radio operator who communicated with ground stations via [[wireless telegraphy|radio telegraph]].

Beginning in the 1930s, both civilian and military pilots were required to be able to use Morse code, both for use with early communications systems and for identification of navigational beacons that transmitted continuous two- or three-letter identifiers in Morse code. [[Aeronautical chart]]s show the identifier of each navigational aid next to its location on the map.

In addition, rapidly moving field armies could not have fought effectively without radiotelegraphy; they moved more quickly than their communications services could put up new telegraph and telephone lines. This was seen especially in the [[blitzkrieg]] offensives of the [[Nazi German]] [[Wehrmacht]] in [[Poland]], [[Belgium]], [[France]] (in 1940), the [[Soviet Union]], and in [[North Africa]]; by the [[British Army]] in [[North Africa]], [[Italy]], and the [[Netherlands]]; and by the [[U.S. Army]] in France and Belgium (in 1944), and in southern Germany in 1945.