Thermal Weapon Sight II

Army, Sep 2005 by Gourley, Scott R

The U.S. Army's AN/PAS-13 thermal weapon sight (TWS) family is a second-generation forward-looking infrared (FLIR) weapon sight that provides today's warfighters with substantial advantages over alternative image-intensified night sight designs. Over the past few years, the TWS family has been fielded in support of Operation Enduring Freedom (OFF) and Operation Iraqi Freedom (OIF) where it has provided users with a new dimension of tactical capability and flexibility.

Manufactured by Raytheon, the original TWS I family includes three different models-light, medium and heavy-with approximate operational ranges of 550 meters, 1,100 meters and 2,200 meters, respectively.

In December 2003, while simultaneously fielding TWS I systems to both OEF and OIF warfighters, the Army recognized an expanded need for thermal sight capabilities and resolicited the TWS I sight program. The resulting TWS II contract awards were made in March 2004.

"The [TWS II] award went equally to two contractors-DRS and BAE-in terms of the quantities and the scope of the work," explained Dan Kitts, thermal director for Product Manager Sensors and Lasers. Both contractors were awarded base quantity and award options that total up to almost 30,000 systems over four or five years.

As with the TWS I family, the TWS II program encompasses three models from each of the two contractors: light, medium and heavy. The light thermal weapon sight will primarily be used on M16/M4-series weapons; the medium thermal weapon sight will be used on the M249 squad automatic weapon and M240-series machine gun; and the heavy thermal weapon sight will be used on the M2 .50-caliber machine gun, Mk 19-series 40 mm automatic grenade machine gun, and M107 .50-caliber long-range sniper rifle. In addition, the heavy variant of the sight will be fielded to platoon and squad leaders for enhanced situational awareness.

According to Lt. Col. Jim Smith, U.S. Army Product Manager, Sensors and Lasers, TWS II represents a leap ahead in multiple technologies over the current TWSI designs.

"They both provide the same basic function: a thermal image with reticle, mated to an individual weapon, to allow for engagements in limited visibility conditions," Smith said. "The big differences between TWS I and TWSII include the fact that the TWS II family is significantly lighter and it enjoys some technology that makes the image clearer; and, because we've got two producers on the contract, we have competition that also allows us to procure the systems for a lower price."

Another significant advantage of the TWS II design involves power requirements.

"We use AA batteries in all three sights: light, medium and heavy," Smith added. "On the previous TWS I, the medium and heavy models used a military-specific battery-BA 5347-[in both disposable and rechargeable versions]. But, through feedback from soldiers, we've moved all three of the sights to AA batteries. Also, the TWS II uses less battery power than the TWS I version, so it provides better power management. For instance, the TWS I light version, while it did use AAs, used eight AAs. In contrast, TWSII uses four AAs for the light version."

While the decreased battery requirements and enhanced performance issues will certainly meet with warfighter approval, the most appreciated benefit will likely be the overall weight reduction. The current light model with batteries weighs 2.7 pounds. The new ones will be 1.9 pounds. The current medium is 5.0 pounds and will come down to 2.8 pounds in TWS II. The heavy weight will drop from 5.3 pounds to 3.8 pounds. Equivalent weight reductions apply to both the BAE and DRS models.

As of this writing, contractor testing is under way for both BAE and DRS models, with government developmental testing starting in mid-July 2005. Current plans call for a subsequent limited user test to be conducted in the September time frame.

"That [limited user test] will serve as the operational test to justify materiel release and fielding," Smith said. "There are new technologies and new vendors, and we want to make sure that we get the systems into soldiers' hands for testing prior to putting it into the field."

While the new systems will retain the same primary AN/PAS-13 designator as the TWS I, the BAE models will be further identified as AN/PAS-13C and the DRS models will be AN/PAS-13D. (The current TWS I systems are designated AN/PAS-13B.)

Based on the anticipated success of the limited user testing, the first "C" and "D" models will arrive in the hands of warfighters in November 2005. Both contractor teams are understandably proud of their participation in this significant warfighter enhancement.

According to Bruce Zukauskas, BAE Systems' IR Imaging Systems (IRIS), director, Military Programs, "The TWS II thermal weapon sights that BAE Systems' IRIS business unit, located in Lexington, Mass., is producing will provide the warfighter with enhanced night targeting and firing capability, independent of darkness, smoke and other common battlefield obscurants.