Two MV-22B Ospreys with Marine Medium Tiltrotor Squadron (VMM) 166 get refueled before continuing a training exercise at the Grand Canyon, July 24. The Grand Canyon was the turning point during the exercise with VMM-166. - Two MV-22B Ospreys with Marine Medium Tiltrotor Squadron (VMM) 166 get refueled before continuing a training exercise at the Grand Canyon, July 24. The Grand Canyon was the turning point during the exercise with VMM-166.