Anon
This official War Office manual, issued in July 1916, was produced to assist troops in identifying aircraft operating over the front and to reduce incidents of friendly fire. It includes photographs, silhouettes, and national markings of British, French, Belgian, and German aircraft and airships. The manual’s principal instruction-'Troops should on no account fire on an aeroplane unless the German black cross is distinctly visible'-reflects the challenges of early aerial recognition.At the outbreak of war in August 1914, the Royal Naval Air Service deployed unarmed reconnaissance aircraft to France, but ground forces lacked reliable means of distinguishing friendly machines. Early misidentification led to British aircraft being fired upon by their own troops. As an interim measure, Union Jack insignia were painted on the undersides of wings to signal friendly status; these markings were soon replaced by the roundels that became standard among Allied air services as the war progressed.