MIM-23 Hawk

The Raytheon MIM-23 HAWK ("Homing All the Way Killer") is an American medium-range surface-to-air missile. It was designed to be a much more mobile counterpart to the MIM-14 Nike Hercules, trading off range and altitude capability for a much smaller size and weight. Its low-level performance was greatly improved over Nike through the adoption of new radars and a continuous wave semi-active radar homing guidance system. It entered service with the US Army in 1959.

In 1971 it underwent a major improvement program as the Improved Hawk, or I-Hawk, which made several improvements to the missile and replaced all of the radar systems with new models. Improvements continued throughout the next twenty years, adding improved ECCM, a potential home-on-jam feature, and in 1995, a new warhead that made it capable against short-range tactical missiles. Jane's reported that the original system's single shot kill probability was 0.56; I-Hawk improved this to 0.85.

Hawk was superseded by the MIM-104 Patriot in US Army service by 1994. The last US user was the US Marine Corps, who used theirs until 2002 when they were replaced with the man-portable short-range FIM-92 Stinger. The missile was also produced outside the US in Western Europe, Japan and Iran. The US never used the Hawk in combat, but it has been employed numerous times by other nations. Approximately 40,000 of the missiles were produced.

Development of the Hawk missile system began in 1952, when the United States Army began studies into a medium-range semi-active radar homing surface-to-air missile. In July 1954 development contracts were awarded to Northrop for the launcher, radars and fire control systems, while Raytheon was awarded the contract for the missile. The first test launch of the missile then designated the XSAM-A-18 happened in June 1956.

By July 1957 development was completed, by which time the designation had changed to XM3 and XM3E1. Very early missiles used the Aerojet M22E7 which was not reliable. The problems were resolved with the adoption of the M22E8 engine.

The missile was initially deployed by the US Army in 1959, and by the US Marine Corps in 1960.

The high complexity of the system, and the quality of tube-based electronics, gave the radars in the early Hawk systems a mean time between failures (MTBF) of only 43 hours. The improved Hawk system increased this to between 130 and 170 hours. Later Hawk versions improved this further to between 300 and 400 hours.

Improved Hawk or I-Hawk
The original Hawk system had problems engaging targets at low altitude—the missile would have problems picking the target out against ground clutter. The US Army began a program to address these issues in 1964 via the Hawk Improvement Program (Hawk/HIP). This involved numerous upgrades to the Hawk system:

The system entered service during 1972, the first unit reaching operational status by October. All US units were upgraded to I-Hawk standard by 1978.

Product Improvement Plan
In 1973 the US Army started an extensive multi-phase Hawk PIP (Product Improvement Plan), mainly intended to improve and upgrade the numerous items of ground equipment.

Hawk Missile Restore Reliability (MRR)


Low clutter enhancements

Hawk missile ILM (Improved Lethality Modification)

Hawk mobility and TMD upgrades

Phase IV

Hawk XXI (Hawk 21)

The Hawk system consists of a large number of component elements. These elements were typically fitted on wheeled trailers making the system semi-mobile. During the system's 40-year life span, these components were continually upgraded.

The Hawk missile is transported and launched from the M192 towed triple-missile launcher. A self-propelled Hawk launcher, the SP-Hawk, was fielded in 1969, which simply mounted the launcher on a tracked M727 (modified M548), however the project was dropped and all activity terminated in August 1971.

The missile is propelled by a dual thrust motor, with a boost phase and a sustain phase. The MIM-23A missiles were fitted with an M22E8 motor which burns for 25 to 32 seconds. The MIM-23B and later missiles are fitted with an M112 motor with a 5-second boost phase and a sustain phase of around 21 seconds. The M112 motor has greater thrust, thus increasing the engagement envelope.

The original MIM-23A missiles used a parabolic reflector, but the antenna directional focus was insufficient, when engaging low flying targets the missile would dive on them, only to lose them in the ground clutter. The MIM-23B I-Hawk missiles and later uses a low side lobe, high-gain plane antenna to reduce sensitivity to ground clutter in addition to an inverted receiver developed in the late 1960s to give the missile enhanced ECCM ability and to increase the Doppler frequency resolution.

A typical Basic Hawk battery consists of:

A typical Phase-III Hawk battery consists of:

The Hawk missile has a slender cylindrical body and four long chord clipped delta-wings, extending from mid-body to the slightly tapered boat-tail. Each wing has a trailing-edge control surface.

In the 1970s, NASA used surplus Hawk missiles to create the Nike Hawk sounding rocket.

The original missile used with the system. The 119 lb (54 kg) warhead produces approximately 4,000 8-gram (0.28 oz) fragments that move at approximately 4,500 mph (2,000 m/s) in an 18 degree arc.

The MIM-23B has a larger 163 lb (74 kg) blast-fragmentation warhead, a smaller and improved guidance package, and a new M112 rocket motor. The new warhead produces approximately 14,000 2-gram (0.071 oz) fragments that cover a much larger 70 degree arc. The missile's M112 rocket motor has a boost phase of 5 seconds and a sustain phase of 21 seconds.

The motor's total weight is 871 lb (395 kg) including 650 lb (295 kg) of propellant. This new motor improves the engagement envelope to 0.93 to 24.85 mi (1.5 to 40 km) in range at high altitude, and 1.6 to 12.4 mi (2.5 to 20 km) at low altitude. The minimum engagement altitude is 200 ft (60 m). The missile was operational in 1971. All US units had converted to this standard by 1978.

The Hawk and Improved Hawk structure was integrated into one system—AN/TSQ-73 air defense missile control and coordination system, called Missile Minder or Hawk-MM. It consists of the following components: MPQ-50 Pulse Acquisition Radar, MPQ-48 Improved Continuous Wave Acquisition Radar, TSW-8 Battery Control Central, ICC Information Coordination Central, MSW-11 Platoon Command Post, MPQ-46 High Power Illuminator, MPQ-51 Range Only Radar and the M192 Launcher.

Introduced around 1982 with improved ECCM capabilities.

Unknown upgrade to the MIM-23C. The C and D missile families remained separate until the missiles' exit from service. It is not clear exactly what the difference between the two missiles - however it seems likely that the D family missiles represent an alternative guidance system, possibly home on jam developed in response to Soviet ECM techniques that were used by Iraq during the Iran-Iraq War.

Low level/multi jamming

An upgraded to the MIM-23C/D missiles improved guidance for low level engagements in a high clutter/multi-jamming environment. Introduced in 1990.

New body section

A 1995 upgrade consisting of a new body section assembly for the MIM-23E/F missiles.

New warhead + fuzing (anti-TBM)

Introduced around 1994. Enhanced lethality configuration warhead with 35 gram (540 grain) fragments instead of the I-Hawks 2 gram (30 grain) fragments. MIM-23K Hawk missiles are effective up to 66,000 ft (20,000 m) altitude and up to 28 mi (45 km) in range. The missile also includes a new fuze to make it effective against ballistic missiles.

New fuzing + old warhead

Retains the I-Hawks 30 grain warhead, but with the new fuze.

The original Hawk system used 4 or in some models 6 radars: to detect (PAR and CWAR), to track (CWAR and HPIR) and to engage (HPIR and ROR) targets. As the system was upgraded the functionality of some of the radars was merged. The final iteration of the system consists of only 2 radars, an enhanced phased array search radar and an engagement radar (HPIR).

The pulse acquisition radar is a long-range, high-altitude search radar.

The search radar used with the basic Hawk system, with a radar pulse power of 450 kW and a pulse length of 3 µs, a Pulse Repetition Frequency of 800 and 667 Hz alternately. The radar operates in the 1.25 to 1.35 GHz range. The antenna is a 22.0 ft × 4.6 ft (6.7 m × 1.4 m) elliptical reflector of open lattice construction, mounted on a small two-wheeled trailer. Rotation rate is 20 rpm, the BCC - Battery Control Central and the CWAR are synchronized by the PAR revolutions and the PAR system trigger.

Introduced with the I-Hawk system, the improved-PAR. The system introduces a digital MTI (Moving Target Indicator) that helps separate targets from ground clutter. It operates in the 500 to 1,000 MHz (C-band) frequency range with radar pulse power of 450 kW.

A X-Band 3D range-gated doppler radar system used with the Hawk XXI system. It replaces both the CWAR and PAR components of the Hawk system. MPQ-64 Sentinel provides coverage out to a range of 47 mi (75 km), rotating at 30 rpm. The system has a mean time between failure of around 600 hours, and can track at least 60 targets at once. It can elevate up to +55 degrees and depress to −10 degrees.

This X Band Continuous wave system is used to detect targets. The unit comes mounted on its own mobile trailer. The unit acquires targets through 360 degrees of azimuth while providing target radial speed and raw range data.

MPQ-34 Hawk CW Acquisition radar with a power rating of 200 W and a frequency of 10 GHz (X-Band) Built by Raytheon. Replaced by MPQ-48.

The Improved Hawk version of the CW acquisition radar doubled the output power and improved the detection ranges:

Hawk Improved Continuous Wave Acquisition Radar or ICWAR. The output power is doubled to 400 W, this increases the detection range to around 43 mi (70 km). The radar operates in the 10-20 GHz (J band). Other features include FM ranging and BITE (Built in test equipment). Frequency modulation is applied to the broadcast on alternate scans of the ICWAR to obtain range information.

Some changes to the signal processing allow the radar to determine the targets' range and speed in a single scan. A digital DSP system is added which allows a lot of the processing work to be done on the radar directly and forwarded directly via a serial digital link to the PCP/BCP.

The early AN/MPQ-46 High Power Illuminator (HPIR) radars had only the two large dish-type antennas side by side, one to transmit and one to receive. The HPIR automatically acquires and tracks designated targets in azimuth, elevation and range. It also serves as an interface unit supplying azimuth and elevation launch angles computed by the Automatic Data Processor (ADP) in the Information Coordination Centre (ICC) to the IBCC or the Improved Platoon Command Post (IPCP) for up to three launchers. The HPIR J-band energy reflected from the target is also received by the Hawk missile.

These returns are compared with the missile reference signal being transmitted directly to the missile by the HPIR. Target tracking is continued throughout the missile's flight. After the missile intercepts the target, the HPIR Doppler data is used for kill evaluation. The HPIR receives target designations from one or both surveillance radars via the Battery Control Centre (BCC) and automatically searches a given sector for a rapid target lock on. The HPIR incorporates ECCM and BITE.

This X Band CW System is used to illuminate targets in the Hawk Missile Battery. The unit comes mounted on its own mobile trailer. Unit automatically acquires and tracks designated targets in azimuth elevation and range rate. The system has an output power of around 125 W operating in the 10-10.25 GHz band. MPQ-39 was an upgraded version of the CWIR, Continuous Wave Illumination Radar, MPQ-33.

The radar operates in the 10-20 GHz (J band) region. Many of the electron tube components in earlier radars are replaced with solid-state technology.

The majority of the remaining tube electronics are upgraded to solid state. Also, an electro-optical tracking system, the daytime only OD-179/TVY TAS (Tracking Adjunct System) is added for operation in a high ECM environment. The TAS was developed from the US Air Forces TISEO (Target Identification System Electro-Optical) by Northrop. It consists of a video camera with a ×10 zoom lens. The I-TAS which was field tested in 1992 added an Infra Red capability for night operation as well as automatic target detection and tracking.

Upgraded with the addition of the LASHE (Low-Altitude Simultaneous Hawk Engagement) system, which allows the Hawk to engage multiple low level targets by employing a fan beam antenna to provide a wide-angle, low-altitude illumination pattern to allow multiple engagements against saturation raids. This antenna is rectangular. This allows up to 12 targets to be engaged at once. There is also TV/IR optic system for passive missile guidance.

Pulse radar that automatically comes into operation if the HPIR radar cannot determine the range, typically because of jamming. The ROR is difficult to jam because it operates only briefly during the engagement, and only in the presence of jamming.

A Ku Band (Freq: 15.5-17.5 GHz) pulse radar, the power output was 120 kW. Pulse length 0.6 µs at a pulse repetition frequency of 1600 Hz. Antenna: 4 ft (1.2 m) dish.

FDC (Hawk Phase III and Hawk XXI) - Fire Distribution Center. C4I unit, enabling modern command, control, communications and Force Operation. Color displays with 3D map overlays enhance the situation awareness. Introduces the real-time exchange of air picture and commands between the Hawk units. Make-ready capability for SL-AMRAAM and SHORAD/vSHORAD systems.

The Israelis have upgraded the Phase 2 standard with the addition of a Super Eye electro-optical TV system for detection of aircraft at 19 to 25 mi (30 to 40 km) and identification at 11 to 16 mi (17 to 25 km). They have also modified their system for engagements at altitudes up to 79,000 ft (24,000 m).

A composite system firing AIM-7 Sparrow missiles from a modified 8 round launcher. The system was demonstrated at the China Lake weapons test site in 1985. There are currently no users of the system.

At "Safe Air 95" AMRAAM missiles were demonstrated being fired from a modified M192 missile launcher. The normal battery radar is used for the engagement, with the missile's own radar used for terminal homing. Raytheon and Kongsberg are offering this system as an upgrade to the existing Hawk system. This proposal is aimed particularly at Hawk operating countries that also have AIM-120 AMRAAM in their inventory. Norway is currently operating this type of system as NASAMS.

As part of what became known as the Iran-Contra affair, Hawk missiles were some of the weaponry sold to Iran, in violation of an arms embargo, to fund the Contras.

The Islamic Republic of Iran Air Force used a number of MIM-23 Hawk missiles for carriage on F-14 Tomcat fighters in the air-to-air role under a program known as Sedjil, or Sky Hawk. Iran has also modified its ground-based Hawk systems for carriage on a convoy of 8×8 wheeled vehicles and adapted the launchers to carry Standard RIM-66 or AGM-78 missiles with two Standard missiles per launcher.

The Iranian Air Force also used limited numbers of an air-to-surface version of Hawk called Yasser, which consisted of a Hawk missile body with its forward section replaced by the warhead of an M117 bomb. The tail fins were also modified with fairings on their wingtips. It remain unclear what, if any, guidance system was used, but suggestions have included Beam riding and Manual command to line of sight.

The Iranian Air Force has its own version of the MIM-23 Hawk. Their copy of the overall system is called Mersad. Iran produces two missiles for use with their Mersad system, Shalamcheh missiles and Shahin missiles. Iran claims both missiles are under production.

In November 2018, Iran unveiled a canister launcher for its Mersad system with the Shahin and Shalamcheh missiles modified into the body of a Sayyad-2. It appeared again in November 2019, but with 3 canisters instead of 2. The systems was named Mersad-16.

Norway has developed its own Hawk upgrade scheme known as the Norwegian Adapted Hawk (NOAH) which involves the lease of I-Hawk launchers, HPI radars and missile loaders from the United States and their integration with Kongsberg 'Acquisition Radar and Control System' (ARCS) battle management stations and Hughes (now Raytheon) AN/TPQ-36A airspace surveillance radars. The NOAH system became operational in 1988. It was replaced by NASAMS in the period 1995-98, which retains ARCS but replaces the Hawk missiles with AIM-120 AMRAAM launchers.

Future developments were expected to include the introduction of an Agile CW Acquisition Radar (ACWAR), an evolution of the Hawk CW radar technology. It would perform full 3-D target acquisition over a 360° azimuth sector and large elevation angles. The ACWAR programme was initiated to meet increasingly severe tactical air defence requirements and the equipment is being designed for operation of Hawk in the late 1990s and beyond. However, the ACWAR programme was terminated in 1993.

These countries have implemented Phase I and Phase II improvements.