United States army soldiers sit on a AH-64D Longbow Apache helicopter manufactured by Boeing Co. during a media preview of the Seoul International Aerospace &amp; Defense Exhibition 2011 at Seoul Airport in Seongnam, South Korea, on Monday, Oct. 17, 2011. Armored vehicles, trainer jets and weapons will be on display this week at South Korea's biggest aerospace and defense exhibition, as the nation works to triple annual military exports by the end of the decade. Photographer: SeongJoon Cho/Bloomberg Photo: SeongJoon Cho, Bloomberg