FIM-92A Stinger Weapons System: RMP & Basic
Developed by the United States Army Missile Command as a successor to the Redeye Weapon System, the Stinger missile provides forward, short-range air defense against low-altitude airborne targets. All services have deployed the Stinger missile to protect combat forces, forward bases, and/or high-value targets. The Stinger is launched from a number of platforms: the shoulder-launched Man-portable Air Defense System, Avenger (HMMWV), Bradley Linebacker, Light Amphibious Vehicle – Air Defense (LAV-AD), Kiowa Warrior (OH-58D), and Special Operations Black Hawks (MH-60). The Stinger is intended to fulfill the Short-Range Air Defense (SHORAD) until 2018.
The Stinger system consists of a Stinger round encased in its launch tube and a separate gripstock assembly.
The “fire-and-forget” Stinger missile employs a passive infrared seeker to home in on its airborne target. A passive infrared seeker emits no radiation that a target aircraft can detect, and, instead, guides on the infrared energy (heat) emitted by the target. Because the Stinger employs a passive homing seeker, it is a “fire-and-forget” weapon that needs no guidance from the operator after firing, unlike other missiles that track the reflection of a designator beam, requiring the operator to maintain a lock on the target. This allows a Stinger operator to take cover, relocate, or engage other targets immediately after firing a Stinger.
The Stinger system features a proportional navigation system, integrated Indentification Friend or Foe (IFF) interrogation, and threat adaptive guidance. Proportional navigation enables the missile to effectively hit moving targets by injecting a multiplier factor into course corrections so that the missile overcorrects for a target’s evasive maneuvers, leading the target to a successful interception. The integrated IFF subsystem allows the Stinger operator to query a target aircraft to determine if it is friendly. Before firing, the operator depresses a button on the gripstock assembly, emitting a coded radio signal. Aircraft equipped with friendly IFF systems will recognize the coded signal and respond with the appropriate coded reply. The IFF subsystem emits one tone if it authenticates a friendly aircraft, and another if the aircraft is unknown. The IFF subsystem is intended to prevent friendly-fire incidents. The Stinger’s threat adaptive guidance takesover in the final stages of its approach to the target, slightly shifting the missile’s aim from the target’s IR hotspot to more vulnerable areas of the aircraft.
As early as 1946, the War Department Equipment Board concluded that the existing .50 caliber machine gun did not have sufficient range or velocity to be effective against targets of the future, particularly low-flying aircraft. The Amry experimented with various antiaircraft machine gun configurations, mounting various caliber machineguns on radar-controlled carriages. In 1951, the Army Equipment Development Board released requirements for a guided, surface-to-air missile, leading to the development of the HAWK air defense system. HAWK did not meet requirements for a lightweight, man-portable, low-altitude air defense weapon, and private contractors developed prototypes for such a weapon to demonstrate to the Army. The Army adopted a system developed by Convair/Ponoma (later General Dynamics’ Ponoma Division), named Redeye for its single IR seeker.
During the 1960s, the military introduced the Redeye into Marine Corps and Army units, providing those units with their first lightweight, shoulder-fired surface-to-air missile. Certain units began receiving Redeye missiles for training purposes in 1967; Redeye achieved IOC in Oct. 1967. But by 1961, it was clear that the Redeye system failed to fulfill at least three core capabilities. The Redeye was not fast enough, could not maneuver soon enough, and could not discriminate well enough to successfully engage its targets.
Advance development of the Redeye II began in 1967 as an outgrowth of the Advanced Sensor Development Program which sought to the Redeye with an all-ascpect engagement capability. Development of the Redeye II, renamed as the XFIM-9A Stinger in March 1972, was awarded to General Dynamics in June 1972. To reduce production costs, design changes were implemented in 1975 to components from the missile and place them in the receiver. The basic Stinger achieved IOC in Feb. 1981. Stinger units replaced Redeye units on a one-for-one basis throughout the next decade.
To date, the U.S. military has fielded four variants of the Stinger missile system: the basic Stinger, Stinger POST, Stinger RMP, and Stinger RMP Block I. In addition, the Army planned to field the Stinger RMP Block II, but the Army divested itself of that program in the FY 2000 budget. The Army has also fielded an Air-to-Air Stinger (ATAS) adapted for self-defense use by helicopters and light air units. Product improvements to the Stinger have enhanced the missile’s capabilities by integrating advances in technology to cope with advances in IR countermeasures and to provide the missile with new capabilities.
The Stinger – Passive Optical Seeker Technique (POST) variant replaces the original reticle-scan analog seeker with a dual IR and ultraviolet (UV) detector employing rosette-pattern image scanning and digital processing. The new seeker enhanced the missile’s target detection capabilities, allowing it to discriminate between a target, countermeasures, and background clutter. Development of Stinger-POST began in 1971, with production running from 1981 to 1987. By 1987, when production of both the basic Stinger and Stinger-POST ended, more than 15,000 basic Stinger and almost 600 Stinger-POST missiles had been produced.
The Stinger-Reprogammable MicroProcessor (RMP) variant adds additional microprocessor power and is highly countermeasures resistant. External software reprogrammability allowed upgrades without costly retrofit as the threat evolved. Upgrades to the Stinger-RMP missile correct known operational deficiencies. Manpower and readiness problems plagued the Army force modernization program in the early 1980’s. It seemed that whenever a new system was put into the hands of the soldier, actual field performance often failed to match the standards predicted during its development. The Stinger anti-aircraft missile, for example, was designed to hit incoming aircraft better than 60 percent of the time. But if it had been placed in service as originally designed, it would actually have achieved hits only 30 percent of the time when operated by soldiers in combat units. The Stinger’s problems were eventually corrected. Operational deficiencies were discovered during testing of the Stinger-RMP missile in the late 1980s, and the Secretary of Defense directed the Army to correct the deficiencies and then operationally test the fixes. The proposed operational test, which consisted of 24 missile firings, was approved by DOT&E via the TEMP in 1991. The Stinger-RMP missile test program was suspended during Operation Desert Storm, and the missile was rushed into the field in preparation for war. After the war, the Army proposed a two-phased upgrade program, Stinger-RMP Block I and Stinger-RMP Block II.
The Stinger-RMP Block I corrects deficiencies in the Stinger-RMP missile to improve precision and performance. Software and hardware changes incorporate a new Roll Frequency Sensor/Seeker, a smaller battery, and an improved computer processor and memory. A ring laser gyro eliminates the need to super elevate prior to firing while other changes improve the accuracy and IRCCM capabilities of the missile. Block I upgrades will “support the Army’s Air and Missile Defense strategy until 2021” (6).
Stinger-RMP Block II, cancelled in the Army’s FY 2001 budget, proposed to improve both hardware and software, including an advanced imaging focal plane array, roll frequency sensor, new battery, signal processing, and advanced software. The Army anticipated producing approximately 9,500 Stinger-RMP Block II missiles.
The Air-to-Air Stinger [ATAS] is an adaption of the man portable Stinger System. It is a light weight missile designed to engage low altitude targets. A major milestone in the improvement of the Air-to-Air Stinger (ATAS) Block-1 missile was demonstrated on 19 November 1996 at Yuma Proving Ground, AZ. An OH-58D piloted by CPT Bob Blanchett, US Army Test and Evaluation Command (TECOM), successfully acquired, tracked, engaged, and destroyed a QUH-1 drone helicopter deploying countermeasures at a range greater than 4500 meters. This firing also demonstrated the capabilities of the improved missile to successfully engage a target without the requirement for super- elevation.
All Air-to-Air Stinger (ATAS) Block II missiles will be modified existing Stinger RMP missiles. The Block II retrofit program will add the Block I modifications plus incoporate a starring IR focal plane array seeker, a new battery, and advanced signal processing capabilities. The new seeker will permit engagements of helicopters in clutter out to the kinematic range of the missile. The missile and launcher will be 1760 compatible. The Block II program will also extend shelf, improve accuracy and IRCCM capabilities, and will provide a full night capability.
The first Stinger Reprogrammable Micro Processor (RMP) missile was successfully fired by a Kiowa Warrior while acquiring the target through the seeker slaving mode at Yuma Proving Ground on 6 November 1997. This mode of acquiring the target dramatically simplifies the procedure and should decrease the acquisition/engagement time lines in most instances. Essentially, the system slews the Stinger missile’s seeker to an off-axis position coincident with the Mast Mounted Sight’s (MMS) line of sight (LOS). Considering the missile seeker’s relatively small field of view, the capability to accurately direct the seeker onto a target being tracked by the MMS is a significant advantage. In practicality, the pilot no longer has to meticulously fly the missile to the target by aligning the center cross with the MMS LOS cue. He merely flies the aircraft to the “ballpark” of the MMS LOS and initiates first detent, allowing the seeker to slew to the target, uncage and begin tracking it. This capability will afford the greatest advantage while acquiring from a hover position in unstable wind conditions with the RMP missile. Seeker slaving is enabled by the Improved Master Controller Processor Unit (IMCPU) which is included with the digitized Kiowa Warriors. Non-digitized Kiowa Warriors may be equipped with seeker slaving by adding a card in the Integrated System Processor. Eventually, all Kiowa Warriors will gain seeker slaving as they are converted to the digital configuration.
|Primary function||To provide close-in, surface-to-air weapons for the defense of forward combat areas, vital areas and installations against low altitude air attacks.|
|Manufacturer||Prime – Hughes Missile System Company
Missile – General Dynamics /Raytheon Corporation
|Propulsion||Dual thrust solid fuel rocket motor|
|Length||5 feet (1.5 meters)|
|Width||5.5 inches (13.96 centimeters)|
|Weight||12.5 pounds (5.68 kilograms)|
|Weight fully armed||34.5 pounds (15.66 kg)|
|Maximum system span||3.6 inches (9.14 cm)|
|Range||1 to 8 kilometers|
|Sight ring||10 mils|
|Fuzing||Penetration, impact, self destruct|
|Ceiling||10,000 feet (3.046 kilometers)|
|Speed||Supersonic in flight|
|USMC Units||Low-Altitude Air Defense (LAAD) Battalions: 3 active duty, 2 reserve|
|Guidance system||Fire-and-forget passive infrared seeker|
|Rate of fire||1 missile every 3 to 7 seconds|
|Type of fire||“Fire-and-Forget”|
|Unit Replacement Cost||$38,000|
|Total program cost (TY$)||1060 systems $7281M|
|Average unit cost (TY$)||$6M|