Spc. Jose Palomino, Spc. James Cobb, and Spc. Kenneth Waller, look at a modified M240 machine gun that is mounted in a mock-up door frame from a CH-47 Chinook helicopter during the 2011 Army Aviation Association of America's Annual Professional Forum and Exposition in Tennessee. The M240's turret mount has been modified to ensure the weapon doesn't hit the window frame.