News: GPS-guided parachutes increase safety in re-supply
by Lance Cpl. James B. Hoke
AL ASAD, Iraq (April 18, 2006) -- The cargo bay doors of a KC-130J Hercules opened, bringing the night air into view, as a chill wind circulated through the inside of the plane. Five Marines braced themselves against the front of the cargo bay watching the two remaining parachute systems attentively.
The massive plane jumped as its airspeed slowed to half of what it had been moments before. A heavy hum vibrated through the walls of the aircraft, as the pilots powered up its engines and aimed it toward the stars. The two crates slid from the bay and disappeared into the darkness.
For the past five years, the Marine Corps has been utilizing a different style of parachute than the traditional round system used to airdrop heavy packages. This new parachute system, the Sherpa, has the ability to guide itself to the drop zone from up to 25,000 feet in the air and 15 miles away, landing within 100 yards of the targeted point of impact while carrying up to 2,200 pounds of supplies.
"The Sherpa is one system of precision-guided airdrop systems," said Staff Sgt. Christine Weber, an assistant air delivery project officer with Infantry Weapons Section, Raids and Reconnaissance, Marine Corps Systems Command. "There are many systems in the family of precision-guided systems that utilize the Global Positioning System to 'fly' to a target."
Equipped with a 1,200-square-foot canopy, the Sherpa is programmed with the information of where it needs to go, as well as how long after it falls from the aircraft before it opens the parachute.
After it is programmed, the GPS-guided parachute attached to its cargo is loaded aboard an aircraft, repeatedly checked for safety issues, flown close to the drop zone and tossed from the plane to make the rest of the way on its own.
"The main canopy steering lines are connected to the control lines in the airborne guidance unit, which operates with two servo motors," said Weber, a 30-year-old native of Charlotte, N.C. "The motors turn to 'reel in' the control lines, allowing for the parachute to turn. The turns are determined by the mission that is programmed into it and based on winds and the target point. The GPS allows for the system to know where it is in the sky and then determine how it needs to get to where it is going."
According to Cpl. Christopher M. Bird, an air delivery specialist with 1st Air Delivery Platoon, Combat Logistics Company 117, Combat Logistics Battalion 7, Combat Logistics Regiment 1, 1st Marine Logistics Group, the Sherpa can also be controlled manually by the service members who will be receiving the supplies it is carrying.
"If they couldn't get to the target point where the Sherpa was supposed to land and wanted to get it closer to them, they could flip a switch to beacon mode on the hand controller," said Bird, a Jonesboro, Ark., native. "The Sherpa will come towards the hand controller emitting the beacon. The operator can also operate it manually with a joystick on the hand controller."
However, the Sherpa isn't considered the parachute to use for everything the Marine Corps needs parachutes for.
"The Sherpa is not good for all missions," said Weber, a resident of Fredericksburg, Va. "It has its own applications. It is good for clandestine operations where you want to reduce detection, as well as for areas that are small and remote."
According to Bird, another setback the Sherpa has is that it cannot wield as much weight as conventional parachutes.
"You can't drop as much weight with them as you can with a regular parachute," said Bird, a 24-year-old graduate from West Side High School. "We can drop things as large as a Humvee with the regular parachutes, but we wouldn't be able to drop something like that with the Sherpa because it would max out the weight."
According to Weber, the Marine Corps Warfighting Lab first purchased five Sherpa systems in 2001 for evaluation.
"The systems were maintained and tested by the Marines of 5th Air Delivery Platoon, which is now disbanded," said Weber, a Charlotte Catholic High School graduate. "The Sherpa has been used in Iraq since 2004 when U.S. Army Natick Soldier Center fielded two units to the Marines of 1st Air Delivery Platoon for use in the area of responsibility.
"Those systems were an older model, the Sherpa 900s, which delivered smaller weights than the 1200 models we have now," she added. "Based on the use of those systems, an Urgent Universal Needs Statement was submitted to Headquarters Marine Corps, expressing a need for this capability. As a result, the Marine Requirements Oversight Council awarded $2 million to purchase 20 of our current Sherpa 1200 systems."
Although 20 of the Sherpa systems were purchased, only 10 have been fielded in Iraq.
"Right now, the systems have been used by Marines with 2nd Air Delivery Platoon out of Camp Lejeune, North Carolina, and by 1st Air Delivery Platoon from Camp Pendleton, California," said Weber. "The plan is to keep these systems over here in Iraq through the different rotations, as has been done up to this point."
It states on the Global Security site at http://www.globalsecurity.org, the Joint Precision Air Drop Systems are being further developed in hopes of one day achieving a family of computer-guided cargo parachutes capable of supporting 21-ton loads.
The website further explained that smaller versions of the system that can support between 2,200 and 10,000 pounds aren't due to be fielded until 2008.
However, the Sherpa is not yet expected to completely take over airdrops by the Marines who use them.
"The Sherpa and other GPS-guided systems can prove to be valuable assets to have in special cases that require precision and the need to keep aircraft out of the immediate threat level of small-arms fire. I don't think that they will completely replace conventional airdrop due to shear cost," Weber stated. "To deliver large quantities of gear, the conventional method still packs more bang for the buck."
According to Bird, the Sherpa system is a blessing to the Marines on the ground.
"If it ever happened where a team was out there and needed to be re-supplied, but could only be re-supplied by the air, as they were cut off or couldn't get ground supplies, we could do it with the Sherpa," Bird concluded. "This system allows us to get it to them by the air, as close as possible and without it falling into the wrong hands."