Between 1909 and the outbreak of World War I in 1914, Blériot produced about 900 aircraft, most of them variations of the Type XI model. Blériot monoplanes and Voisin-type biplanes, with the latter's Farman derivatives dominated the pre-war aviation market. There were concerns about the safety of monoplanes in general, both in France and the UK. The French government grounded all monoplanes in the French Army from February 1912 after accidents to four Blériots, but lifted it after trials in May supported Blériot's analysis of the problem and led to a strengthening of the landing wires. The brief but influential ban on the use of monoplanes by the Military Wing (though not the Naval Wing) in the UK was triggered by accidents to other manufacturer's aircraft; Blériots were not involved.