Birmingham, Ala., native Staff Sgt. Christopher Doss, center, the maintenance sergeant, Company D, 1st 'Attack' Battalion, 227th Aviation Regiment, 1st Air Cavalry Brigade, 1st Cavalry Division, jokes with his Soldiers Spc. James Kelley, left, an Apache mechanic from Buellton, Calif., and Sgt. Jesse Coble, right, an Apache mechanic and squad leader from Paducah, Ky., as they work on the rotor head of an Apache helicopter at Camp Taji, Iraq. Doss will often resort to humor to keep his Soldiers moods light and to help them work through the oppressive heat.