Avenger fills the Line of Sight-Rear (LOS-R) portion of the Forward Area Air Defense System (FAADS). It has a two man crew and can operate in day or night, clear or adverse weather conditions. The system incorporates an operator's position with displays, fire control electronics, and the Standard Vehicle Mounted Launcher (SVML). The SVML supports and launches multiple Stinger missiles (Basic Stinger, Stinger-POST (Passive Optical Seeker Technique), or Stinger-RMP (Reprogrammable MicroProcessor). Additionally, the SVML incorporates a .50 caliber machine gun and necessary fire control sensors for both weapons. The contribution this highly mobile, short range air defense system makes to the Army's full-dimensional protection enhances the ground components prospects for dominant maneuver by preserving key elements of the force.

The Avenger weapon system includes a 360°, rotating turret mounted on a heavy HMMWV chassis with an upgraded suspension and 200 amp alternator. The baseline configuration consists of a gunner's turret with missile pods mounted on each side. Each missile pod, called the standard vehicle-mounted launcher, can hold four missiles that can be removed and fired in the MANPAD employment configuration. The rotation of the turret and the elevation of the standard vehicle-mounted launcher is accomplished by electric motors powered by batteries carried in the base of the weapons system. The vehicle's power system is in parallel with the Avenger battery set. The .50 caliber machine gun affords a measure of self-protection by providing additional coverage of the Stinger missile's inner launch boundary.

The Avenger weapons system has an unobstructed, 360° field of fire and can engage at elevations between -10 and +70°. The modular design of Avenger allows complementary missiles and/or rockets to be installed on the launch arms in addition to (or in place of) Stinger missiles. The gunner has sufficient visibility out of the turret for visual target acquisition, tracking, and engagement. A combination glass sight is used through which the gunner looks to aim the missiles and on which a driven reticle display is projected. The driven reticle indicates the aiming point of the missile seeker to confirm to the gunner that the missile seeker is locked onto the desired target.

Avenger's sensor package includes a forward-looking, infrared (FLIR), carbon dioxide, eye-safe laser range finder and a video autotracker. These sensors provide Avenger with a target acquisition capability in battlefield obscuration at night and in adverse weather. Range data from the laser range finder is processed by the Avenger fire control system to provide a fire permit for missile and gun use. A driven reticle and other data are displayed on the forward-looking infrared display in the same manner as the optical sight.

The turret drive is gyro-stabilized to automatically maintain the missile pod aiming direction regardless of the vehicle motion. The turret drive control is operated by the gunner with a hand controller on which the missile and gun controls are placed. The gunner can transfer tracking control to an automatic turret drive control system that uses signals for the uncaged missile seeker of the FLIR video autotracker to track the target until the gunner is ready to fire. The firing sequence is entirely automated, including superelevation and lead, so that the gunner need merely push the fire button to initiate the fire sequence and immediately select and prepare the next missile for firing. These systems enable Avenger to accurately and rapidly launch missiles.

Avenger is equipped with two VHF-FM frequency-hopping radios (i.e., SINCGARS) and an integrated remote terminal unit. When this capability is tied into the Marine air command and control system, Avenger can be configured to automatically slew to a target that appears on the radar display. This capability is known as "slew to cue." Targets pointed out by ground-based air defense units, tactical air operations center operators, or the LAAD section leader can be accepted or rejected by the gunner. Until the gunner responds to the cue, the gunner maintains complete control of the Avenger turret. If the gunner accepts a pointer, the turret automatically slews to the azimuth of the target. The gunner then resumes control of the turret and completes the engagement process by acquiring, tracking, and engaging the target. "Slew to cue" is a capability inherent to any radar picture.

Avenger completed a two phase IOT&E in 1989. Phase I consisted of acquisition and tracking trials at Fort Hunter-Liggett. Phase II consisted of Stinger missile firings at White Sands Missile Range. The Avenger system was found to be operationally effective by DOT&E in the B-LRIP to Congress dated February 28, 1990. Avenger was found to be operationally suitable with some limiting factors. These limiting factors were: back blast damage to the cab at some firing azimuths and elevations; excessive hydrogen chloride gas levels in the cab; need for a improved voltage regulator; and the need for an environmental control unit/ primary power unit (ECU/PPU) for the gunner's cupola.

The Army reports that they have corrected the limiting factors. Prior to fielding, Boeing reinforced the vehicle doors to prevent back blast damage. Also, cab openings and doors received new seals or gaskets to reduce the HCL gas levels. A retrofit was performed to address the voltage regulator problem. A redesigned regulator and a larger alternator were installed on all fielded vehicles, while the new items were cut into production.

An ECU/PPU design was tested and found to address the heat build-up in the cupola. During testing, the ECU/PPU was found to create an EMI problem with the Forward Looking Infrared (FLIR) and the Radar Control Unit Video. Before fixes could be incorporated, the SBA contracted firm producing the ECU went bankrupt. An alternate source was identified when another firm purchased the defaulter. Fixes have been explored as part of the contract restart. A follow-on test was completed by Redstone Technical Test Center to verify ECU/PPU performance and compatibility. First production units have been accepted.

The new ECU/PPU underwent environmental testing at RTTC, Huntsville. Since the testing used a fixture, not the system, the testing did not provide sufficient operational data needed by OPTEC and DOT&E to provide an adequate evaluation of this issue.

OPTEC (OEC) is working with the PM to plan an ECU/PPU environmental test which satisfies the data requirements for the operational evaluators. The test and evaluation of the Avenger in accordance with the DOT&E approved TEMP dated 20 June 1987 will conclude once the ECU/PPU limiting factors outlined in the B-LRIP dated 28 February 1990 have been adequately addressed. Army testing of alternate source ECUs will examine the following questions: (1) Does the ECU cool the gunner's turret in extreme temperatures? (2) Is the ECU reliable? (3) Are there any safety problems with the ECU? (4) Does the ECU degrade the operational capabilities of the Avenger, for example, the range of the SINCGARS radios? Technical testing to date has addressed these questions, however the Army has yet to test a "production representative" item. When Army technical testing is complete, data will be provided to OPTEC and DOT&E for review and assessment. When the B-LRIP limiting factors have been completely addressed, Avenger will be dropped from DOT&E oversight.

The AVENGER is operated by a two-man crew. The gunner operates from inside the turret, and the driver operates from the driver's compartment. The health hazard assessment identified heat stress as a potential health hazard. Testing indicated that both the gunner and driver became uncomfortably hot following 60 minutes of firing when the outside temperatures near 85¡F. When the gunner and driver operated in Mission-Oriented Protective Posture (MOPP), significantly higher heat loads were observed. Actual firing missions for the AVENGER may last up to 12 hours, and the associated heat loads on the gunner and driver may be well in excess of acceptable levels. The health hazard assessment report recommended installation of a cooling system at all crew positions.

In early 1999 the Army exercised a $14.6 million option on future production of an upgrade kit for Avenger air defense units that will greatly increased their effectiveness beginning 1st Qtr FY00. The Slew-To-Cue (STC) subsystem, a major upgrade enhancement to the Avenger, is expected to improve Avenger's target acquisition, tracking and engagement range by about 50 percent while increasing the number of engagements and kills by more than 50 percent. The system will also significantly improve Avenger's battlespace performance. Using STC, the Avenger will be able to accept digital early warning data and automatically slew the turret in both azimuth and elevation, centering the target in the gunner's field of view. Targeting data is provided by Forward Area Air Defense (FAAD) Command, Control, Communications and Intelligence (C3I). The FAAD C3I equipment provides early warning/alerting, a complete air picture, slew-to-cue and target IFF information. This improvement not only improves the efficiency and effectiveness of the Avenger, but also allows it to kill the broadening spectrum of 21st century threats, including CMs and UAVs. The $14.6 million contract is for low-rate initial production, full production, contractor logistic support for approximately 100 Avenger fire units.