1 / 2 Show Caption + Hide Caption – (Photo Credit: U.S. Army) VIEW ORIGINAL
2 / 2 Show Caption + Hide Caption – Soldiers from the 4th Battalion, 27th Field Artillery Regiment from Fort Bliss, Texas, remove the Precision Guidance Kit (PGK) canard cover and ensure the canards spin before firing the round during Early User EUA at Yuma Proving Ground, Ariz., Octob... (Photo Credit: U.S. Army) VIEW ORIGINAL

PICATINNY ARSENAL, N.J. -- As American troops prepare for the spring fighting season in Afghanistan, they have been training with a new capability to suppress insurgents.

This March Picatinny Arsenal began delivering troops the XM1156 Precision Guidance Kit (PGK), a new artillery technology that will keep American troops safer and reduce collateral damage in urban areas.

"PGK allows the current stockpile of conventional ammunition to be transformed into near-precision capability, allowing for more precise fires," explained Lt. Col. Will McDonough, Product Manager for Guided Precision Munitions and Mortar Systems (PdM GPM2S).

Soldiers install the PGK fuze into the fuze well of conventional 155 mm high explosive M549A1 and M795 cannon artillery projectiles, replacing the standard fuze. This allows troops to turn their conventional artillery rounds into "smart" munitions.

The fuze performs in-flight course correction of the round to improve accuracy. Its near-precision accuracy will reduce the number of projectiles required to hit targets, which in turn reduces collateral damage and risk to civilians.

With PGK, the round's accuracy improves to less than 50 meters Circular Error Probable (CEP), regardless of range to the target. Fifty meters CEP means that if you drew a circle around a target at 50 meters radius, the rounds have to fall inside the circle 50 percent of the time.

Conventional artillery rounds have an accuracy of 267 meters CEP at maximum ranges.


PGK also reduces the risk of fratricide because it enables safer final protective fires.

Final protective fire is the term for U.S. artillerymen firing rounds downrange to create a defensive barrier around infantry units in order to stop enemies from approaching the unit. Final protective fires are traditionally considered risky because the artillery targets are close to U.S. troops.

However, PGK has a "fail safe" built in. If the PGK equipped artillery round does not go close to the target, it will not detonate.

"PGK ensures that any rounds that would normally land more than 150 meters (from the target) fail safe," McDonough said. "Fail safe is when a round continues on its trajectory and lands, but it does not explode."

"About five seconds out it makes an 'arm decision' on whether it expects (to hit the target). If it's within 150 meters it will detonate, if it's going to be outside of 150 meters it fail safes," McDonough said.

This reduced fear of misfires, "gives infantrymen the confidence to call in indirect fires on more occasions," McDonough said.


Soldiers from field artillery units will set PGK using the Enhanced Portable Inductive Artillery Fuze Setter (EPIAFS).

Once the fuze is set, the shell is loaded in the same fashion standard 155 mm rounds are loaded. Once fired, the fuze uses accurate position data from satellites to adjust the round's canards and steer the round to the target.

PGK was fielded via an Urgent Materiel Release.

New equipment training with troops in Afghanistan began in March, with its first successful firing in training April 2. Initial fielding will be complete by the end of June.

The prime contractor for PGK is Alliant Techsystems (ATK), which is contracted to produce and deliver approximately 2,400 XM1156 PGKs for the U.S. Army and 700 for the U.S. Marine Corps.

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