Army Aims for More Precise Ways to Drop Troops, Cargo.
The Soldier Center is part of the U.S. Army Soldier and Biological Chemical Command, headquartered at the Aberdeen Proving Ground, Md., just outside of Washington, D.C.
"Airdrop is not going to be just for the airborne, kick-down-the-door force any more," Doucerte told an industry briefing sponsored recently in Sparks, Nev., by the National Defense Industrial Association. Instead, he said, airdrops are going to be used much more widely within the Army.
The new parachutes make use of emerging technologies to put troops and equipment more precisely where they are needed, with fewer casualties or damage, Doucette claimed. "Dumb airdrop--the way we do it today--is at the mercy of the wind," he said. "Accuracy is nonexistent."
Now, Doucette explained, "we're looking at gliding, steerable parachutes, with dramatically reduced rates of descent." Some examples:
* The Advanced Tactical Parachute System (ATPS)--a replacement for the T-10 parachute, used by U.S. airborne troops since the 1950s--will reduce a jumper's rate of descent by 25 percent, limiting the impact and chances of injury when the trooper hits the ground.
* The Guided Parafoil Air Delivery System (GPADS), a gliding system, uses autonomous steering to deliver loads of cargo ranging from 700-pound bundles of food to 5-ton trucks.
* The Wind-Supported Air Delivery System-Leaflet Delivery System (WSADLDS) is a powered parafoil, with its own self-guided navigation system for psychological operations forces to use in dropping leaflets or other products.
* The Semi-Rigid Deployable Wing (SDW), resembling a glider, delivers bulk cargo under 600 pounds from a height of 25,000 feet or a distance of 15 miles.
* The Affordable Guided Airdrop System (AGAS) uses four pneumatic "muscles" to protect a parachute's cargo from being damaged while landing.
The concept of the parachute dates back 500 years to the Renaissance inventor, Leonardo da Vinci. It had little utility, however, until World War I, when an Austrian pilot on the Russian front in 1916 made the first parachute jump from a burning aircraft.
Later in that same war, U.S. Army Brig. Gen. Billy Mitchell first propose transporting troops and equipment by air and landing behind enemy lines.
During World War II, the concept was adopted widely, both by Allied and Axis powers throughout the European and Pacific theaters. For example, the U.S. Army's first airborne division--the 82nd--made four combat jumps while fighting its way from Sicily, through France and into Germany.
From the earliest days, however, airdrops have been vulnerable to the wind, which can blow parachutes away from the target zone, and a rapid rate of descent, which can result in casualties and cargo damage.
"In Bosnia, the winds were notorious," Doucette explained. The wind data available to the aircrews was 12 hours old, he said. As a result, "the airdrops were thousands of meters off--maybe more.
"We were trying to drop humanitarian rations and other supplies to refugees surrounded by enemy troops," Doucette said. "Often, we didn't know whether the parachutes were going to land on-target or among the enemy.
The old T-10 parachute, used by paratroopers for nearly half a century, was designed to handle a gross weight of 250 pounds, including the soldier, weapon, pack and other equipment and personal supplies. Today's soldiers are bulkier than previous generations, and so are their loads, Doucette noted. Each parachute, he said, now must carry nearly 400 pounds.
The T-10s can handle the increased weight, but they descend at a faster rate--an average of 21 feet per second--and hit the ground harder, all to often resulting in sprained ankles or even broken legs.
The new ATPS reduces the rate of descent to 16 feet per second, shrinking the number of injuries by more than 50 percent.
This change is a real "combat multiplier," said Doucette, because injuries of-ten reduce the combat force by three--the injured soldier and two comrades, who help him get safely off the battlefield.
The Army selected the design for the ATPS in May after tests at Yuma Proving Grounds, Ariz. The winning design-by Para-Flite Inc., of Pennsauken, N.J.--"looks a lot different," compared to the round-topped T-10, explained Doucette. "It looks like a box," he said, with four deep sides and a relatively flat top.
The new version is substantially larger than the T-1O and is "very, very stable," he said. The reserve parachute can be deployed using either hand. A new harness mounts the reserve near the shoulders, instead of the waist, for improved safety.
A total of 52,000 of the new parachutes are to be fielded to all the services, beginning in 2005, Doucette said.
The Army also is developing a small automatic-opening device to make sure the reserve canopy opens if the main chute fails and the jumper is incapacitated or disoriented. To determine when to open, the device uses sensors that measure such factors as acceleration along three axes and barometric pressure.
The device is still in development. Results, thus far, are promising, Doucette said, but it is important that the technology be reliable.
"If the reserve parachute were to open prematurely--inside the plane, for example--it would be a tremendous hazard," he noted.
The new cargo parachutes rely upon global-positioning systems (GPS) to keep track of where they are in the sky and to guide themselves more precisely to relatively small drop zones, Doucette explained.
The new parachutes can deliver loads to within 100 meters of a target, he said. They can be dropped from heights up to 25,000 feet--well beyond the range of small arms and shoulder-fired surface to air missiles. They can glide as far as 12 miles after being dropped, helping aircraft and their crews stay out of harm's way.
The Army also is developing a system for low-level airdrops. Currently, Doucette said, airdrop systems require a minimum of 750 to 2,000 feet for heavy equipment drops. Survivability studies, however, indicate that airdrop operations above 500 feet significantly increase the risks to aircraft from hostile ground fire.
Thus, Doucetre said, the Army is working on a 500-foot Low-Velocity Airdrop Delivery Capability (500' LVADC), which would make it possible to drop heavy equipment from altitudes 30 percent lower than at present, offering greater accuracy and reduced load dispersion.
The leaflet system uses a parafoil, a 100-horse-power-engine, an airborne guidance unit and software for mission planning and execution. It can deliver up to 600 pounds of leaflets, one at a time, in stages, or at different locations. It can be deployed from a C-130 or launched from a ground vehicle, such as a HMMWV (Humvee). Once it is deployed, it uses GPS navigation to reach its target, and once the mission is complete, the leaflet system can return to its base. "It really is a poor man's UAV (unmanned air vehicle)," said Doucette.
AGAS is a soft-landing system designed for use with existing parachutes and standard airdrop packages, according to Glen Brown, president of Vertigo Inc., of Lake Elsinore, Calif., which developed it for the Army. The use of existing systems reduces airdrop costs, he said.
AGAS employs four pneumatic muscle actuators (PMAs) to help protect airdrop loads from the shock of landing, Brown explained. Airdropped cargo hits the ground even harder than a paratrooper--at speeds of up to 28 miles per hour. The results can be smashed crates and damaged equipment, he noted.
To protect cargo from this fate, the Army in recent years has used "honeycomb kits" of insulation, but the packing process is costly in terms of labor and time, especially under the deadline pressures imposed by combat.
AGAS replaces the insulation with PMAs, which are braided, high-strength fiber tubes that connect the four corners of the pallet with the parachute. When inflated at very high pressure, just before landing, the PMAs contract forcefully, negating the impact of landing.
"The PMAs are very powerful," Brown said. "They really jerk up the pallet."
The Army has tested this system successfully with cargo weights of up to 2,200 pounds. In September, tests will be conducted at Yuma with two parachutes and a weight of a HMMWV, approximately 10,000 pounds, Brown said. Next year, the Army plans to test a 20,000-pound drop, he said. The Army plans to field AGAS in 2007.
The Army is developing a system, using a cluster of 12 parachutes, to airdrop up to 60,000 pounds, the weight of some combat vehicles. The 60,000-pound Low-Velocity Airdrop System-still years away from fielding--would make it much easier to move heavy combat and construction into combat zones, Brown said. The maximum that a C-130--the most common military air transport--can carry is 42,000 pounds, he pointed out.
"One of our ultimate goals is to eliminate the platforms that the cargo sirs on during the drop," Brown said. The parachute rig would be hooked directly to the cargo, he explained, and without the platform the whole load would be much lighter.
"Eventually," added Doucette, "we might drop vehicles with the crews inside of them. And they could just drive away as soon as they land, sort like a 21st century glider force."
The airdrop research and development program cost about $10 million, Doucette said. But the technologies that it has spawned promise to make airdrop operations much more widely available throughout the military services within the next few years, he added.
"As it becomes safer, easier and cheaper to use airdrop, more and more commanders are going to discover that it is becoming an increasingly attractive way to get troops and equipment quickly into hot spots around the world."
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|Title Annotation:||new parachute design and airdrop safety|
|Date:||Aug 1, 2001|
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