MARINE CORPS BASE CAMP PENDLETON, Calif. -- An MV-22B Osprey with Marine Medium Tiltrotor Squadron 161 "GreyHawks" waits to lift off as members from multiple uniits board the aircraft to conduct fast roping excercises aboard Marine Corps Base Camp Pendleton Calif., Oct 1. The units practice with the Osprey due to the differences in the rotor wash compared to other rotary aircraft. - MARINE CORPS BASE CAMP PENDLETON, Calif. -- An MV-22B Osprey with Marine Medium Tiltrotor Squadron 161 "GreyHawks" waits to lift off as members from multiple uniits board the aircraft to conduct fast roping excercises aboard Marine Corps Base Camp Pendleton Calif., Oct 1. The units practice with the Osprey due to the differences in the rotor wash compared to other rotary aircraft.