A Russian Ka-52 military helicopter participates in a flying display during the 50th International Paris Air Show at the Le Bourget airport in Paris, France, June 18, 2013. The Paris Air Show runs from June 17 to 23. [Photo/Xinhua]

A Russian Ka-52 military helicopter participates in a flying display during the 50th International Paris Air Show at the Le Bourget airport in Paris, France, June 18, 2013. The Paris Air Show runs from June 17 to 23. [Photo/Xinhua]