Stinger weapon systems in Operations Desert Storm and Desert Shield
During the 1991 Gulf War, Stinger systems were deployed extensively by a number of the Coalition forces but, as far as is known, did not engage any Iraqi targets. Post-war debriefing of Iraqi command staff credited Stinger with deterring the use of the 500-strong Iraqi fleet of helicopters that included numerous Hind gunships.
The then latest version of the Stinger - Stinger-RMP equipped with the latest MOD IV software - was deployed with at least three of the four US armed services in support of the Gulf operations. Basic Stinger and export variant Stinger-RMP systems were also deployed with the armed forces of several of the other nations of the Coalition forces.
Virtually every US Army ground combat unit had the Stinger either in the MANPADS role or as the principal armament of the wheeled Avenger PMS fire unit.
Since initial deployment Stinger has, in combat, defeated more modern fixed-wing aircraft and helicopters than any other fighter, helicopter or missile system worldwide since the Second World War.
The US Marine Corps used the same two-man MANPADS team as the US Army, with the team (gunner and team chief) carried in an HMMWV with four ready to fire Stingers and two reload missile rounds.
The US Navy used MANPADS teams aboard its ships, primarily for close in defence against small aircraft and very small surface craft. The US Army used the ATAS variant on its OH-58C helicopter in the air-to-air role, whilst the US Air Force may have deployed some of its specially trained Air Police in the MANPADS role to guard some of the airbases it used in the Arabian Peninsula region.
Description
A Stinger system comprises the launcher assembly with a missile, a grip-stock, an IFF interrogator and an argon gas Battery Coolant Unit (BCU) (which consists of the squib activated argon gas coolant unit and electrical generating chemical battery).
The launcher assembly consists of a glass fibre launch tube with frangible end covers, a sight, desiccant, coolant line, gyro-boresight coil and a carrying sling. A detachable grip-stock which has a receptacle for the BCU is fitted with an IFF connector. The grip-stock is also fitted with an impulse generator (BCU energised), a seeker head uncage bar, a weapon launch trigger, an AN/PPX-1 IFF interrogator switch and a foldable antenna and control electronics for the missile gyro.
The missile has a two-stage, three-phase rocket motor. A separable launch motor ejects the missile followed by an advanced `boost-sustain' motor which provides high supersonic speed and agility out to maximum range. In its FIM-92A version it is fitted with a second-generation cooled passive IR conical scan reticle seeker head with discrete electronic components to provide signal processing. They process the IR energy received from the target in the 4.1 to 4.4 ?m wavelength region to determine its relative angle and then, by using a proportional navigation guidance technique, continually predict an intercept point.
In the FIM-92B version the reticle seeker unit is replaced by one that uses an optical processing system. This has two detector materials, one sensitive to IR (in the waveband region 3.5 to 5.0 ?m) and the other responsive to UV energy (in the waveband region 0.3 to 0.4 ?m), together with two microprocessors which are integrated into microelectronic circuitry for the signal processing phase. The latest Stinger-RMP takes this one stage further by introducing a microprocessor reprogramming facility into the circuitry to allow for new threat characteristics and guidance tailoring. The logic allows for recognition of countermeasures and their filtering out from the seeker's guidance picture.
In all cases the seeker output is sent as steering data to the guidance assembly which converts it into guidance signal format for the control electronics. This module then commands the two movable (of four) forward control surfaces to manoeuvre the weapon on to the required intercept course. The control concept used is known as the single channel rolling airframe type and, as such, considerably reduces both the missile weight and manufacturing costs. As the weapon nears its target, the seeker head activates its Target Adaptive Guidance (TAG) circuit within one second of impact to modify its trajectory away from the exhaust plume towards the critical area of the IR target itself. The fuzing system allows for both contact activation as well as missile self-destruction after 20 seconds of flight time following the launch. The Picatinny Arsenal warhead carried has a smooth fragmentation casing to ensure that the desired blast/fragmentation effect is achieved.
A typical tactical engagement follows this sequence of events. Once alerted to a target the gunner shoulders the system, inserts the BCU into its grip-stock receptacle and unfolds the IFF antenna. They then remove the front protective cover of the launcher tube to reveal the IR or IR/UV transparent frangible disc, raise the open sight assembly and connect their beltpack IFF interrogator unit via a cable to the grip-stock. The gunner is now ready to acquire the target visually. They do this by using the sight and estimating its range with the estimation facility of the system. If required, they now interrogate the target using the AN/PPX-1 system. This can be done by the gunner without having to activate the weapon. The azimuth coverage of the 10 km range IFF system is essentially the same as that of the optical sight enabling the gunner to associate responses with the particular aircraft that is in view. An audio signal 0.7 second after the IFF challenge switch is depressed provides the gunner with the cue as to whether the target is friendly or an unknown for possible engagement.
If they decide that it is unfriendly they continue to track the aircraft and activate the weapon system by depressing the impulse generator switch. This causes the impulse generator to energise the BCU which then releases its 6,000 PSI pressurised argon gas coolant to the IR detector and generates a dual-polarity ?20 V DC output for at least 45 seconds. The cooling takes 3-5 seconds. It provides all the prelaunch electrical power required for the seeker coolant system, gyro spin-up, launcher acquisition electronics, guidance electronics, activation of the missile's onboard thermal battery and ignition of the ejector motor.
The seeker is allowed to look at the target through the IR or IR/UV transparent front launcher disc and, when sufficient energy is received by the detector for acquisition to have occurred, an audio signal is sent to the gunner. Total time required for tracking and missile activation is about 6 seconds. They then depress the seeker uncage bar and, using the open sight, insert the superelevation and lead data.
The newer versions of Stinger (Block 1 and Block 2) preclude the need to superelevate the missile.
Once this is accomplished, the gunner depresses the firing trigger which activates the missile battery. This powers all the missile functions after launch and operates for around 19 seconds until the dual-polarity ?20 V DC output drops below the required minimum for use. A brief time delay operates, following which the umbilical connector to the grip-stock is retracted and a pulse is sent to ignite the ejector motor. Total time to motor ignition from depression of the firing trigger is only 1.7 seconds. Upon ignition the initial thrust generated imparts roll to the missile airframe and starts the fuze timer system. The missile and its exhaust then break through the frangible discs at either end of the launcher tube.
Before the missile completely clears the end of the tube, the ejector motor burns out in order to protect the gunner from the rocket blast, and two movable control surfaces spring out. Once it clears the tube, the two fixed and the four fixed and folded tail fins open out and the ejector motor is jettisoned. The missile then coasts to a predetermined safe distance from the gunner where the fuze timer ignites the dual-thrust Atlantic Research Mk 27 solid-propellant rocket motor. When the correct acceleration rate is reached after one second of flight, the time delayed Magnavox M934 time delayed impact fuzing circuit for the 1 kg HE blast, smooth cased fragmentation warhead is armed and the self-destruct timer started.
The seeker continues to track the target throughout the flight with the electronics processing the received signals to eliminate or reduce the line of sight pointing angle to the target. The weapon flies a proportional navigation path to the interception point near to which the TAG circuit is activated and a signal is generated within the seeker head to add bias to the steering signal causing the missile airframe to guide itself into a vulnerable part of the target. Even if the target is using 8 g manoeuvres the missile is still capable of engaging it.
Once the gunner has depressed the trigger and the missile has left the launch tube, they are free either to get another weapon round, to assemble another missile round for a further engagement (which takes less than 10 seconds), take cover or move to another location.
US Army training needs indicate that 136 hours of instruction are required on the Stinger system before weapon qualification is given. The M60 field handling and M134 tracker head training versions are used for instruction.