Marines from across I Marine Expeditionary Force post security during fast rope inserts on Marine Corps Base Camp Pendleton, Calif. May 9, 2016. This training was a part of a helicopter rope suspension techniques training package facilitated by 1st Air Naval Gunfire Liaison Company, I MEF. Marines and Royal British Commandos practiced these techniques on a rappel tower prior to fast roping out of helicopters hovering nearly 40 feet off the ground. - Marines from across I Marine Expeditionary Force post security during fast rope inserts on Marine Corps Base Camp Pendleton, Calif. May 9, 2016. This training was a part of a helicopter rope suspension techniques training package facilitated by 1st Air Naval Gunfire Liaison Company, I MEF. Marines and Royal British Commandos practiced these techniques on a rappel tower prior to fast roping out of helicopters hovering nearly 40 feet off the ground.