Queen Mary visits aero. shed - Glass negative photogrpah. Public domain.

Photograph shows Queen Mary of Teck leaving the aerodrome at Royal Flying Corps Headquarters at St. Omer, France on July 5, 1917, during World War I. (Source: Flickr Commons project, 2015 and similar image on Imperial War Museums website: http://www.iwm.org.uk/collections/item/object/205078934 )