CHAPTER 2

The Stinger Weapon

To be able to direct and guide Stinger personnel, Stinger section chiefs and platoon leaders must know the weapon itself. This chapter briefly describes the makeup of the Stinger weapon system. It also describes the basic steps the gunner follows in the engagement process. For a more detailed discussion of weapon characteristics and team firing procedures, refer to FM 44-18-1 and (SNF) FM 44-1A (U).

SECTION I

THE STINGER WEAPON SYSTEM

Stinger is a man-portable, shoulder-fired, infrared-homing (heat seeking) guided missile system. It requires no control from the gunner after firing. Stinger has an identification, friend or foe (IFF) subsystem which aids the gunner and team chief in identifying friendly aircraft. Operations at night or in bad weather are restricted by the gunner's ability to see and identify the target.

The Stinger weapon system is composed of four basic items: weapon round, IFF subsystem, shipping and storage containers, and harness.

THE WEAPON ROUND

The Stinger weapon round is made up of a missile round (consisting of a Stinger missile housed within a launch tube) mated to a separable gripstock. A battery/coolant unit (BCU) is inserted into the weapon round to provide prelaunch power to the system. You must have all three items -- missile round, separable gripstock, and BCU -- to have an operational weapon. For IFF capability, an IFF interrogator is connected the launch tube.

A basic load of Stinger weapons consists of four weapon rounds and two missile rounds.

MISSILE ROUND

The missile round is composed of two major parts: the missile and a launch tube. The missile is ejected from the launch tube by a missile launch motor. The launch motor is expended and drops from the missile outside to the weapon. Once the missile coasts to a safe distance from the gunner, the missile flight motor fires and continues to propel the missile in flight. Should target intercept not occur within 15-19 seconds after launch, the missile will self-destruct.

CONTENTS Section I The Stinger Weapon System The Weapon Round Stinger Identification, Friend of Foe, Subsystem COMSEC Items Shipping and Storage Containers Transport Harness Section II The Engagement Process Launch and Intercept Boundaries Engaging Aircraft

The fiberglass launch tube, which houses the missile, provides the main support for all other parts of the weapon round. Both ends of the launch tube are sealed with breakable disks. The front disk is transparent to ir radiation, allowing the radiation to reach the heat-sensitive missileseeker. Both the front and rear disks break when the missile is launched.

SEPARABLE GRIPSTOCK

The separable, reusable gripstock consists of the gripstock assembly and the IFF antenna assembly.

The gripstock contains all the necessary circuits and assemblies that allow the gunner to prepare and launch the missile. Located on the gripstock assembly are the safety and actuator device, uncaging switch, firing trigger, IFF challenge switch, IFF interrogator connector, and BCU receptacle. After a missile is launched, the separable gripstock is removed from the launch tube for reuse. The gripstock can be reused until failure. When the IFF antenna assembly is unfolded and the IFF interrogator is connected to the weapon, it is capable of interrogating aircraft and receiving coded replies.

BATTERY/COOLANT UNIT

The battery/coolant unit (BCU) contains a thermal battery to provide power for preflight operation of the system and a supply of argon gas to cool the infrared detector in the missile seeker. Once activated, the BCU supplies electrical power and seeker coolant to the weapon until launch or for a maximum of 45 seconds. When the system is activated, a BCU is expended. When a BCU is inserted in the weapon, the BCU is considered expended as soon as it is removed. For this reason, three are packed with each missile-round.

STINGER IDENTIFICATION, FRIEND OR FOE, SUBSYSTEM

The Stinger identification friend or foe (IFF) subsystem is a part of the Stinger weapon system. Components of the IFF subsystem used by the gunner are the interrogator and interconnecting cable.

The gunner connects the IFF interrogator to the weapon by using the IFF interconnecting cable. When connected with the Stinger weapon round, the IFF interrogator is capable of transmitting a challenge (interrogation) to a potential target. If an improperly coded reply is received, the aircraft is classified as an "unknown" (possibly a foe). (Detailed IFF interrogation procedures are in FM 44-18-1.)

A programmer/battery charger, code input computer, shipping and storage containers, and code keys are used to support the IFF subsystem. This equipment is located at the section headquarters.

The interrogator is programmed with an interrogation code. It can be programmed to operate in Mode 4 secure mode for 4 days. Within 4 days, a new or recharged battery must be installed and the unit reprogrammed. Unless it is reprogrammed, the system automatically shifts from Mode 4 to Mode 3. It remains in this mode of operation until the batteries are discharged or the system is reprogrammed. Two IFF interrogators are issued per team and four interrogators are kept at the section headquarters for spares. Before an IFF interrogator is reprogrammed, a freshly charged battery pack must be inserted. The battery will be charged for a minimum of 4 hours prior to reprogramming of interrogators. A 4-hour charge will normally allow for 800 interrogations. Operating instructions are found in TM 9-1425-429-12.

COMSEC ITEMS

In addition to the IFF programmer, certain communications security items are required to program the codes into the IFF interrogator.

The TSEC/K1-1A system is the communications security (COMSEC) component of the MARK XII IFF system. Specifically, it provides the cryptographic security necessary for operating in Mode 4. It is not used to operate in Modes 1, 2, or 3/A. The TSEC/K1-1A system consists of the AKAK 3662 code key list (AKAK), the KIK-18A/T SEC code changer key (KIK), and the KIR-1A\TSEC interrogator computer (KIR) shown below.

The AKAK 3662 is the operational code key list for the TSEC/K1-1A system. Editions are composed of 28 operational and two emergency tables providing code settings on a 28-day basis. The two emergency tables are not authorized for use. Individual tables consist of 64 metal pins in the KIK. Each table provides two key settings designated "A" + "B" (Day 1 and Day 2) so that aircraft which are airborne at key change time (2400Z) may shift to the next cryptovariable without rekeying their kit. Editions of the AKAK are classified CONFIDENTIAL and are marked CRYPTO. Individual tables are classified CONFIDENTIAL.

The KIK-18A/TSEC, code changer key is a mechanical device used to cryptographically key the KIR or KIT. The metal pins, which protrude from one end of the device, plug into the code changer assembly of the KIR or KIT to set the code. Once the pins are manually set, the KIK may be used to key any number of KIRs or KITs. The KIK is classified CONFIDENTIAL when set with a code and UNCLASSIFIED when not set.

The KIR-1A\TSEC interrogator computer is used primarily in the ground/surface interrogator of MARK XII-equipped IFF systems. After being cryptographically keyed by the KIK, the KIR can compute individually unique interrogations that are transmitted as challenges through an interrogator to an unidentified aircraft. It also verifies the validity of the coded replies from the aircraft's transponder. The KIK is classified CONFIDENTIAL. Handling instructions are contained in TB 380-41 and NSA manual KAM 25.

SHIPPING AND STORAGE CONTAINERS

The weapon-round container is a reusable aluminum box used for storing an operational weapon round, two spare BCUs, and a set of ear plugs. Four of these containers are issued to each team as part of its basic load. When the weapon-round containers are arranged in the team's 1/4-ton trailer, the two top weapon-round containers are converted into "ready racks." The latches the two top containers are released after securing the containers in the trailer, thereby making the weapons readily accessible to team members.

The missile-round container is a wooden box containing a missile round, three BCUs, and one set of ear plugs. Two missile-round containers are issued to each team as part of its basic load. As rounds are expended, the gunner simply opens a missile-round container, removes the missile round, mates the gripstock of the expended round to the new missile round, and inserts a BCU. He of then has a complete weapon round to use if needed. The empty box is then returned to the trailer. Replacement missile rounds are stored at ammunition supply points (ASP).

TRANSPORT HARNESS

The Stinger basic load is carried on the standard 1/4-ton cargo trailer and is held in place by a transport harness. The transport harness is used to secure the basic load on the trailer. The harness also allows rapid access to the two top weapon-round "ready racks."

SECTION II

THE ENGAGEMENT PROCESS

LAUNCH AND INTERCEPT BOUNDARIES

The engagement process is influenced by Stinger's launch and intercept boundaries, and the size and shape of the boundaries are influenced by many factors. Among these are the type, speed, altitude, and aspect of the aircraft. Stinger can effectively engage all aircraft operating at low level and at ordnance delivery speeds. Proper employment of the Stinger weapon requires understanding of its capabilities and limitations. For a more detailed discussion of Stinger launch and intercept boundaries and other classified information, refer to (SNF) FM 44-1A (U).

ENGAGING AIRCRAFT

The engagement process consists of a series of actions performed by the Stinger team. The team chief and gunner are trained to rapidly perform the procedures, as shown below.