A Marine with Marine Fighter Attack Squadron 122, Marine Aircraft Group 31, 2nd Marine Aircraft Wing, cleans the window of an F/A-18 Hornet before its departure to participate in a Weapons and Tactics Instructor course event aboard Marine Corps Air Station Yuma, Ariz., April 8, 2015. WTI is a seven-week exercise sponsored by Marine Air Weapons and Tactics Squadron 1 designed to provide advanced tactical training scenarios for fleet Marine force units and their sponsored WTI candidates.