U.S. Marine Corps Cpl. Erik C. Valencia, right, an F-35B fixed-wing aircraft mechanic with Marine Fighter Attack Squadron 121 (VMFA-121), 3rd Marine Aircraft Wing, observes the first ever hot load on the F-35B Lightning II in support of Weapons and Tactics Instructor Course (WTI) 1-17 at Marine Corps Air Station Yuma, Ariz., Sept. 22, 2016. The exercise is part of WTI 1-17, a seven-week training event hosted by Marine Aviation Weapons and Tactics Squadron One (MAWTS-1) cadre. MAWTS-1 provides standardized tactical training and certification of unit instructor qualifications to support Marine Aviation Training and Readiness and assists in developing and employing aviation weapons and tactics. (U.S. Marine Corps photograph by Chief Warrant Officer 3 Jorge Dimmer, MAWTS-1 COMCAM)