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Last Updated: Mon Jan 27 11:18:09 UTC 2014

CPMIEC HQ-7/FM-80 / CSA-4 Sino-Crotale
CPMIEC HQ-7/FM-90 / CSA-5 Sino-Crotale
Self Propelled Air Defence Systems

Technical Report APA-TR-2010-0901

Carlo Kopp, BE(hons), MSc, PhD, AFAIAA, SMIEEE, PEng
Martin Andrew, BA(hons), MA, PhD, RAAF(Retd)
Imagery © 2010 Air Power Australia
  September, 2010
Updated January, 2011
Updated April, 2012
Text, Line Art © 2009 - 2012 Carlo Kopp

China continues to manufacture and export the cloned Crotale SAM. The latest HQ-7B/FM-90 Crotale variant is carried on a new Chinese designed 6 x 6 AFV chassis, replacing the cloned French  Thomson-Hotchkiss P4R chassis. Additional image [1] (via Chinese internet).


The HQ-7 is a Chinese clone of the French Thales/Thomson CSF Crotale SAM. During the 1970s the French supplied samples of the Crotale which was promptly reverse engineered. The cloned Crotale has been built in two configurations, a high mobility variant for PLA Army units on a 4 x 4 cloned French Thomson-Hotchkiss P4R armoured vehicle, and a less mobile PLA-AF air field defence system, using either a trailer or a truck platform. Since then, derivative variants have emerged in the FM-90 series, in addition to the shipboard variants. The Thomson-Hotchkiss P4R vehicle uses either a diesel or gasoline engine driving an alternator which powers electrical motors driving the wheels. Chinese sources sometimes label the P4R as a B-20. A naval variant of the Crotale as also been developed.

A four round elevating tube launcher turret is used, mounting the Ku-band Automatic Command to Line Of Sight monopulse radar dish antenna. Export variants are the FM-80 and improved FM-90 with a FLIR tracker and longer ranging missiles. HQ-7/FM-80/90 batteries are typically supported by an acquisition radar system, the FM-90 usually on a new design indigenous 6 x 6 light armoured personnel carrier.

Thomson-CSF (Thales) Crotale


The origins of the prolific Crotale family of missiles lie in a South African order placed in 1964 with French radar and systems integration contractor Thomson-Houston (later Thomson CSF and now Thales) for the development of a point defence SAM system. Funded mostly by the South Africans, and partly by the French government., the system was developed through the late 1960s. The South Africans took delivery of their systems between 1971 and 1973, naming them the Cactus in operational service. The French air force soon ordered the system for airfield point defence use, acquiring twenty batteries by 1978, and naming the system the Crotale, or Rattlesnake [1, 2, 3].

Since the first Crotale was ordered almost 40 years ago, the system has remained in production and a wide range of variants and configurations have been built and exported. The Crotale remains one of the most successful SAM designs ever built, with over 300 systems exported to 15 nations.

The basic design concept and the performance of the early Crotale is closest in most respects to its Soviet contemporary, the early variants of the NIEMI 9K33 Osa / Romb or SA-8 Gecko. Where the two systems diverge is in the regime of deployment, as until the most recent Crotale NG, the Crotale system was mobile but split across  multiple cable connected TELARs and an Acquisition and Co-ordination Unit (ACU) equipped with an acquisition radar; the SA-8 and Crotale NG colocate the engagement and acquisition units on the single TELAR and are capable of autonomous operation.

The Crotale has been produced in a number of consecutive variants:

Crotale 1000 Series (1969):

Baseline Crotale weapon system built in a mobile configuration on the Hotchkiss P4R vehicle or a relocatable container for fixed sites. All system components linked by cables. A typical configuration is two or three P4R TELARs tied to a single ACU.

Crotale 2000 Series (1973):

Enhanced acquisition and tracking by addition of a television channel; addition of IFF capability for deconfliction.

Crotale 3000 Series (1978):

Further enhanced tracking capability by addition of automatic television track capability.

R460/Shahine/SICA (1980):

Unique variant developed for Saudi Arabia following a 1975 order. The Crotale weapon system was rehosted on the Giat AMX-30 tank chassis to improve mobility in soft terrain and survivability against hostile fire, as the Shahine was intended to provide fully mobile air defence for armoured manoeuvre formations.

Crotale 4000 Series (1983):

Replacement of cable interconnections with the LIVH (Liaison Inter Vehicule Hertzienne) radio datalink, which permits separation of up to 3 kilometres between TELARs and ACU, and up to 10 kilometres between proximate ACUs. Improved radar ECCM and addition of thermal imaging tracker channel.

Crotale 5000 Series (1985):

Modernisation of French Crotale systems incorporating a an optical tracker and improved radar antenna to permit acquisition out to 18 kilometres range.

Crotale NG (1990):

The Crotale NG (New Generation) is a deep redesign of the basic Crotale, in which the legacy missile round is replaced by a new VT-1 hypervelocity round which provides a 35 G manoeuvre capability, Mach 3.5 speed, 11 kilometre range, and an 8 metre lethal radius using a new directional warhead. The radar and fire control systems were improved, and the acquisition radar colocated on the turret with the TELAR launchers and engagement radar, making the system fully mobile. The Crotale NG is supplied  self-propelled on a range of different chassis, or on a towed 3 axle trailer.

Crotale Mk.3 (2008):

The Crotale Mk.3 is a further evolution of the Crotale NG. The improved missile round has a range of 16 kilometres, and ceiling of 9 kilometres, and the new Shikra 3D multibeam surveillance radar is a derivative of the Thales Netherlands SMART-S Mk.2 radar.

Variants of the Crotale have been deployed by France, Finland, Greece, Portugal, South Africa, South Korea, Bahrain, Egypt, Morocco, Oman, Pakistan, Saudi Arabia, and the UAE. Chinese HQ-7 Crotales have been exported to Iran, and an Iranian assembled variant has been marketed.

Above, below: Crotale 3000 series Fire Unit on Hotchkiss P4R 4 x 4 vehicle. Note the cable spool above the vehicle engine bay (Thales).

Crotale Acquisition and Co-ordination Unit (ACU) on Hotchkiss P4R 4 x 4 vehicle. The Mirador IV acquisition radar antenna is fully deployed, and hydraulic stabilising supports extended (Thales).

Crotale 3000 series Fire Unit on Hotchkiss P4R 4 x 4 vehicle, with launcher elevated. This image shows the coaxial turret arrangement clearly, with separately driven Castor 2 radar and launcher components (Thales).

China was supplied by France with a small number of Crotale and Sea Crotale systems during the late 1970s, for evaluation purposes. The post Tiananmen embargo prevented import of production quantities. Chinese sources claim that the 2nd Academy reverse engineered the missiles, the 23rd Institute the radar systems, and the 206th Institute the Hotchkiss P4R vehicle. The reverse engineered Crotale and Sea Crotale entered production about a decade later, designated the HQ-7 and HHQ-7 respectively. Export variants have been designated FM-80, and FM-90 in the evolved variant.

In terms of capabilities and performance the HQ/HHQ-7/FM-80/90 closely compare to the Soviet/Russian built Almaz-Antey/Kupol 9K331M/M1 Tor M/M1 SA-15B/C Gauntlet and early configurations of the KBP 2K22M1/2S6M1 Tunguska-M1/ SA-19 Grison SPAAGM missile system.

The key difference is that both Soviet/Russian systems integrate the acquisition radar on the TELAR, and were designed like the 9K33 Osa / SA-8 Gecko before them, to “shoot and scoot”, providing high mobility point defence capability for land force manoeuvre elements. The baseline Crotale, which is the basis of the HQ-9, was built for rapid intra- and inter-theatre redeployment, but limited “shoot and scoot” capability.

The original design aim of the Crotale was to engage supersonic low flying fighters, to provide a rapid reaction terminal point defence for airfields, and other high value static or redeployable targets. PLA Crotale units appear to remain dedicated to this role.

The kinematic performance of the Crotale missile and angular field of regard of the engagement radar are both compatible with the “Counter-PGM” role, which has now become the primary role of the Russian 96K6E Pantsir S1E / SA-22 and 9K331M2E Tor M2E / SA-15D. While the new acquisition radar for the HQ-7B / FM-90 has the technological potential for use in this role - it employs the same antenna technology as the 9K331M2E Tor M2E / SA-15D - there is no evidence to date that the PLA intends to reorient the operational use of the HQ-7B to “Counter-PGM” role.

Equally so, there is no evidence of any indigenous PLA effort to develop a unique replacement for the HQ-7/HHQ-7 series. Given the past propensity of the PLA to extract every possible use out of a mature design, and the inherent growth potential of the Crotale family as demonstrated by the evolution of EU Crotale variants, the most likely outcome is that the HQ-7/HHQ-7 will continue to evolve new variants for the forseeable future.

HQ-7/HHQ-7 / Sino-Crotale Technical Analysis

The HQ-7/HHQ-7 SAM systems are often described as “based on” and “derived from” the Crotale. Close inspection of the wealth of detailed HQ-7/HHQ-7 imagery suggests that the first generation of the HQ-7/HHQ-7 system are almost exact clones of the French originals, with differences which at best qualify as cosmetic, such as the headlight arrangement on the P4R, or the shape of the frangible launch tube covers. The changes observed in newer FM-90 system appear to be primarily in the replacement of the acquisition radar, replacement of the P4R vehicle, and internal enhancements to the system electronics. The Chinese have published very little of substance on the Crotale, in comparison with other indigenous weapons systems.

Accordingly, this technical analysis will be based on the original baseline French Crotale, with the caveat that the PLA may have made numerous incremental detail improvements to the internal design of the system, as has been observed with reverse engineered Russian weapons.

The best single discussion of the design rationale behind the original Crotale is the excellent 1970 Interavia/International Defense Review analysis “Design Philosophy of the Crotale AA System”, authored by le Sueur, who was a design engineer at Thomson CSF involved in the definition and development of the Crotale[2].

The imperative for the development of the Crotale was the emergence of terrain avoidance and terrain following radar as penetration aids for tactical aircraft, permitting them to penetrate especially hilly terrain, abundant in Europe, by using terrain masking to conceal their approach. The combination of transonic or supersonic speed and altitudes between 150 and 330 ft AGL typically results in targets which pop-up above the radar horizon a mere 15 to 25 seconds away from the target. Such short reaction times are a genuine challenge for most SAM systems, and typically beyond the capabilities of 1950s and early 1960s SAM designs which dominated NATO air defences during that period. The then new Soviet MiG-23BN/27 Flogger, Su-7/17/22 Fitter and Su-24 Fencer would this be capable of bypassing most NATO IADS components no differently than USAF F-105D Thunderchiefs and F-111 Aardvarks sliced through North Vietnamese defences.

Figure 1 Low level penetration envelope [2].

Figure 2 Crotale threat engagement requirement [2].

Design requirements for the Crotale were detailed by le Sueur thus [cited][2]:

Design principles

A multi-capability solution to the low altitude problem should therefore provide the following:

1. Radar detection in all weathers of a 1 m2 fluctuating target flying at speeds up to Mach 1.2, amongst ground clutter and fixed echoes of 105 m2 equivalent area (corresponding to a collection of large buildings seen against a rock face 1,500 metres taller).

2.Tracking of the target accurately in this environment, even if it flies at ground level, hugs the side of a hill or valley, or passes through a nodal point close by. Guidance of the missile accurately under whatever conditions the target imposes.

3.Fast reaction, so that the following operations can take place whilst the aircraft in question (flying at Mach 1.2) travels no more than 4 km, allowing an intervention time of just under 10 seconds:
  • detection of the target as soon as it appears,
  • determination of its type (single or multiple),
  • identification friend or foe (with the possibility of interrupting the acquisition/firing sequence at any time in case of a belated 'friendly' response),
  • determination of its course parameters,
  • automatic tracking lock-on,
  • firing of one or several missiles,
  • interception.
Should the attack be of large proportions, this sequence must still take no longer than for a single attacking aircraft. In addition to the above requirements, the weapon system should:
  • classify targets by the urgency of the threat which each represents whenever a fresh attack is detected,
  • engage targets in this order of priority classification,
  • be capable of co-ordinated engagement of several targets on different bearings simultaneously.
4. Firepower sufficient to ensure a kill probability of 90%. This involves:
  • highly accurate missile guidance,
  • a high-acceleration, high-speed missile,
  • missile manoeuvrability, even at maximum range,
  • controlled detonation of the warhead for maximum effect in a position relative to the target's leading-edge and engine infrared sources,
  • a proximity warhead, the destructive range of which is considerably greater than the missile's miss-distance,
  • the possibility of firing several missiles at the same target if needs be, without starting the acquisition sequence again; immediate, automatic realization of the need for this without human intervention; the automatic firing of such a salvo.
5. Mobility comparable to that of the combat formations which the system will protect, particularly cross-country, without degradation of its detection capability; self-propulsion; self-contained operation and air-portability.

6. Maximum reliability in spite of enemy electronic countermeasures. Detection of faults the moment they occur and not when the approach of an enemy aircraft sets off the full operating sequence.

7. Simplified training of operating and maintenance crews.

These design requirements are not dissimilar to such a requirement were it drafted today, indeed the principal differences would be in more challenging specific requirements for ECCM capability and detection performance against low signature targets in clutter.

The design strategy defined for the Crotale was detailed by le Sueur thus [cited][2]:

The following are the solutions which have been adopted to fulfil the stated requirements:

1.A fully coherent [Mirador IV] pulse Doppler surveillance radar. This will detect aircraft of an area equivalent to a 1 m2 fluctuating target flying at radial speeds of 35 to 440 m/s (156 to 890 mph) at altitudes from 0 to 3,000 m (0 to 10,000 ft) and ranges up to 18.5 km (11.5 miles). At maximum range the probability of detection is 90% with each antenna revolution. The chances of a false alarm are low and radar visibility through the fixed echoes is so good that even when Crotale was tested in the most difficult conditions, no ground shadow whatever appeared on the screen. A computer logic circuit correlates the data gathered on each antenna revolution, rapidly extracting all but the useful information and allowing automatic tracking of any aircraft within detection range. So as not to lose the benefits of the fast reaction time, information is renewed at the very high rate of one antenna revolution per second. Using a pulse Doppler radar, this antenna revolution speed is incompatible with precise target definition and suppression of ambiguities and 'blind speeds' within the range limits imposed by the terrain, unless the S-band is used for the surveillance role. The radar coverage is so designed that it immediately provides not only the bearing of the target. but also a first indication of its range and elevation (high, medium or low).

2.Tracking of the target is carried out by a Ku band [Castor 2] monopulse radar, the narrow beam and short pulse of which give very high definition; the use of multiple frequencies gives good protection against jamming as well as very smooth tracking. The tracking radar antenna has been separated from the co-axially mounted missile launchers, in order to reduce its inertia to a minimum. Missile guidance is accurate to within 0.1 milliradians, this unequalled performance being the result of using the beam-riding guidance technique in direct combination with the target tracking technique described above. This process eliminates the mechanical and electronic errors common to systems with separate target tracking and missile guidance equipment.

3. The very fast reaction time required of the system necessitates total automation. Crotale is the first example of a weapon system to be so designed. A computer mounted in the surveillance/target designation vehicle determines whether the target is approaching or receding and its nature (one or several aircraft); it processes the data provided by radar, initiates tracking of each aircraft, and classifies it in terms of immediacy of the threat in relation to other targets already being tracked. After identification of the aircraft as hostile, the computer communicates with its counterparts in the firing unit vehicles, before assigning the target to whichever of the latter is best placed to deal with it. This causes all the uncommitted tracking radar/missile launcher mountings to turn towards the target. The designated fire unit then receives an accurate bearing on the target, together with its approximate elevation and height. The fire unit computer then guides the tracking radar within these limits, by continually updating target elevation and height data (Fig. 3), until the automatic tracking mode locks on. During this period of search, the fire unit computer remains under the overall control of the computer in the surveillance/target designation vehicle. It calculates the interception possibilities and decides when target engagement becomes possible. Once the order to fire is given, several irreversible missile launching procedures take place: internal power is switched on, the autopilot is activated, the missile container is opened, and the missile is fired. At any time between tracking lock-on and interception of the aircraft, a 'friendly' IFF response, however belated, will automatically interrupt the intercept sequence; if this occurs during missile flight, the latter will destroy itself.

On the standard version of the Crotale system, the intervention of human operators has been kept to two levels:
  • In the surveillance/target designation vehicle, an operator assigns the target classified as top priority to the fire unit indicated to him by the computer as being that best capable of dealing with it.
  • In the fire unit, an operator presses the firing button when it illuminates.
These two functions - as we have seen - are not essential, and when the computer calculates that the available reaction time offered by a priority target is incompatible with the real time constants of the human operator, it deprives him of his authority to intervene in the operational sequence.

The attachment of several fire units to the same surveillance unit allows the most flexible and economic defense of various types of point targets. One surveillance unit will therefore be under-utilised in many cases if it is linked with only one firing unit. But more important still, if the fire of the various units co-operating to protect the same target is not co-ordinated, then there is nothing to prevent those fire units whose operating envelopes overlap engaging the most urgent target simultaneously, leaving the field wide open for following aircraft. By ensuring the co-ordination of several firing units against a large-scale attack therefore, the Crotale organisation optimizes their performance.

4.The firepower of Crotale results from the combined effect of several devices which have been incorporated in the system. An advanced operational research study showed that, faced with the threat posed in the next decade and taking account of the restricted range of fire compatible with terrain limitations, the beamriding guidance technique with continuous deviation correction offers a cost-effectiveness ratio superior to any other. Designed and produced by Engins Matra with the assistance of several divisions in the Thomson Brandt group for in particular, the propulsion unit,, the warhead and the transponder, the Crotale missile is gathered by the radar in under 500 metres. Its single-stage motor propels it to Mach 2.3 in 2.3 seconds. and at the limit of its range its speed is still supersonic.

The missile is roll-stabilized in order to allow a high degree of guidance precision and to provide the ability to absorb the high load factors imposed by  crossing targets. Canard-type surfaces provide the required manoeuvrability with a minimum of drag, and at the limit of combat range, the missile still has a manoeuvrability of 7 g which allows it to cope with fluctuations and evasive manoeuvres of the target.

The 15 kg warhead was specially designed for high efficiency: its detonation produces a burst of fragments moving at over 2,000 m/sec localised in space and time, the fragments retaining the same lethality to a distance of 8 metres. The warhead is detonated by an infra-red proximity fuze in the standard version (an electromagnetic fuze is optional) at a point determined by the ground-based computer as a function of the relative positions of the missile and its target.

The flexibility of the digital computer allows full simulation of the firing and intercept sequence before it takes place. This permits, for example, the avoidance of a situation in which a missile could be fired at an aircraft which would be masked by terrain at the theoretical point of interception: a firing lock avoids waste of this missile. In the same way, if it appears that an airborne target will present itself in conditions which would make interception difficult (very high speed, very brief appearance within the limits of action of the missile) so degrading the hit probability, the computer will give authority to launch a salvo of two missiles the moment the operator presses the firing button.

All these provisions have allowed verification during the firing trials that the 90% destruction probability indicated by the design calculations can, in fact, be achieved in reality.

5.To conform to the requirement to support mobile combat forces, it was necessary that the surveillance radar be capable of giving the alarm whilst on the move, so as not to lose the advantage of the very short reaction time by a long detection period. Without this capability, it would be necessary to resort to the classic “leapfrogging” technique with the slowness of movement and the doubling of surveillance equipment which it involves.

The stable oscillator of a pulse Doppler radar is sensitive, in certain frequency ranges, to the mechanical vibrations of vehicles. These generate false alarms which the computer confuses with the actual signal of an airborne target. To eliminate these vibrations, mechanical transmission has been dispensed with and a very flexible suspension adopted for the thermal [internal combustion engine in P4R] motor. The power supplied by this motor, converted into electrical energy, is fed via cables to electric motors on each wheel. The missile launch vehicle uses the same system.      

The first military application of a principle already proven commercially, combined with a very elaborate hydropneumatic suspension system, ensures a smooth ride for the Crotale vehicles on varied terrain, and a high initial starting torque [characteristic of DC electric motors], well above the usual norms for a four wheeled air transportable vehicle of 13 tonnes powered by the 230 SHP motor.

The ACU S-band pulse Doppler Mirador IV acquisition radar is designed to reject 60 dB of ground clutter, and performs a single scan per second. Two stacked beams  for heightfinding are produced by a pair of feeds on a boom, with a third feed for the IFF channel. The digital data processor can concurrently track up to 12 targets on different bearings.

The HQ-7/FM-80 ACU antenna is of a similar configuration to the Mirador IV, with a feed boom and rear V-shaped structural frame which appear identical. The sculpted Mirador  IV reflector is replaced by a truncated concave mesh and frame reflector, which permits a HQ-7 ACU to be easily recognised when compared to the Thomson-CSF original product.

The digital data processing system communicates with the Fire Units through a datalink interface, which employs either cable or radio link channels. The cable allows communication between the ACU and a fire unit up to distances of 400 metres. The alternate VHF-band radio datalink permits communication over distances of 50 to 5,000 metres.

The Fire Unit Thomson-CSF Castor 2J/C pulse Doppler engagement radar employs a circular parabolic reflector with splayed monopulse feeds on a characteristic four spoked strut frame, which appears identical on both HQ-7 Type 345 systems and French built Crotales. The radar operates in the Ku band producing a 1.1° circular pencil beam for target tracking. Three channels are used to permit tracking of a single target and one or two outbound missile round Ku-band transponders, the arrangement intended to minimise the relative angle errors between target and missile tracks. An X-band missile uplink is employed. Frequency agility is employed to minimise susceptibility to jamming. For a more detailed discussion refer HQ-7/FM-80FS/FM-90FS/Type 345 Crotale Engagement Radar.

An infrared tracker with a ±5° FOV is employed to ensure that the antenna boresight is aligned with the missile flightpath vector immediately after launch, before the missile is captured by the guidance command link 500 metres after launch.

Most Crotale systems, including the HQ-7, employ a TV telescope to provide ECCM capability, and redundancy in the event of radar failure.

The Fire Unit digital mission computer is employed to calculate the parallax offset relative to the ACU, acquisition and tracking algorithms, speculative intercept parameters against possible targets, command uplink instructions for missile capture and command link guidance to intercept, fusing control calculations, and missile self destruct commands.

Crotale engagement envelope [1].

Conceptually the HQ-7/Crotale radar suite most closely resembles its Soviet/Russian analogues, the Land Roll system in the 9K33 Osa / Romb / SA-8 Gecko, and the later 9K331 Tor / Tor M/M1 / SA-15 Gauntlet. The French design is cleaner and more compact, and shares the antenna across multiple functions, whereas the Soviet/Russian designs employ additional function specific antennas.

Figure 3, reproduced from le Sueur's paper, shows the transfer of the target track from the ACU to the Fire Unit. The Mirador IV localises the target into an angular box cited at 4 milliradians, which falls well inside the 20 milliradian mainlobe angular coverage of the engagement radar. This permits the Castor 2 to acquire and lock very rapidly, as the acquisition and lock process primarily involves driving the antenna boresight to null the initial angular error, and establishing range and velocity tracks. There is no need for the Castor to perform a search to place the target into the mainlobe.

What specific changes the Chinese may have made to the Mirador IV and Castor 2 in the process of reverse engineering the Crotale has never been disclosed. Given the good quality of the original Thomson-CSF design, there would be few useful optimisations possible to improve upon the basic functions of these radars.

Unvalidated Chinese Internet claims are that the FM-90 is fully digital, and the engagement radar operates in two bands to improve ECCM capabilities - the Russians employed a dual band engagement radar in this class in developmental variants of the 96K6 Pantsir S - and that the FM-90 is intended to engage cruise missiles, ASMs, anti-radiation missiles and aircraft.

Figure.3 [cited] “Diagram showing the interface between the two radars, and automatic tracking lock-on. Key: A - designated tracking envelope; the volume of this envelope depends on the elevation bracket, range bracket and the bearing, which is always given by the surveillance radar to within 4 milliradians. The accuracy of the given bearing obviates the need for a three-dimensional target search by the tracking radar, B - target; C - radar echo on the PPI; D - bearing vector, E - tracking radar beam.[2]

Figure 4, 5, 6 Crotale engagement sequences[2].

 Type 345 engagement radar on towed HQ-7 TELAR (Zhenguan Studio, © 2010 Air Power Australia).

Engagement radar on HQ-7B/FM-90 TELAR (via Chinese Internet).

Type 345 engagement radar on FM-90/HQ-7B TELAR (Zhenguan Studio, © 2010 Air Power Australia).

FM-90 ACU (Zhenguan Studio, © 2010 Air Power Australia).

Detail of FM-90 ACU acquisition radar antenna. This is a mechanically steered rotating 3D planar array design with frequency scanning  of eleven element rows in elevation, likely operating in the upper S-band. The upper IFF array produces a fan shaped fixed beam (via Chinese Internet).

FM-90 ACU acquisition radar antenna backplane and feed detail. Note the coaxial feeds to the electronically steered IFF array elements (Zhenguan Studio, © 2010 Air Power Australia).

FM-90 ACU acquisition radar antenna elevation scan feed (Zhenguan Studio, © 2010 Air Power Australia).

The new FM-90 acquisition radar is a major departure from the Mirador IV and likely has its origins in the family of S-band and L-band planar array acquisition radars developed by CETC. The design is a mechanically rotated planar array with electronic mainlobe steering in elevation, very similar in concept to the new Russian Kupol 9K332 Tor M2/M2E / SA-15D Gauntlet acquisition radar. The FM-90 radar has eleven rows of elements, in 26 columns. This would permit better sidelobe performance than the legacy reflector antenna, but will yield inferior heightfinding accuracy compared to the Tor M2/M2E / SA-15D design. Neither the FM-90 nor the Tor M2/M2E / SA-15D antenna designs are optimal for the crucial “Counter-PGM” role, which requires the ability to accurately track multiple incoming targets in a fixed angular sector, with exceptional heightfinding accuracy to intercept weapons flying steep dive trajectories.

This indicates that the primary role of the FM-90 remains in the engagement of fast jet and low flying helicopter targets. The introduction of a mechanically steered AESA design with a square or near square aspect ratio would be an unambiguous indicator of a role change in the HQ-7 system.

The baseline HQ-9 / FM-80 is hosted on what appears to be an exact clone of the Hotchkiss P4R armoured TELAR / ACU vehicle. This design is, as discussed previously, unconventional. A diesel or gasoline engine is employed to drive an alternator, which in turn drives via a rectifier power supply DC electrical motors on each wheel, the latter coupling torque via a planetary gearing system on each wheel. Messier developed the hydro-pneumatic suspension system. The hydraulic system also powers the three stabilising jacks. The P4R has a road range of 600 km and 60 km/hr road speed to match armoured formations. It can be airlifted by C.160 Transall. Reload time for the TELAR is circa 2 minutes with a proficient crew - comparable to the 9K33 Osa/Romb / SA-8 Gecko.

The new FM-90 6 x 6 vehicle has yet to be publicly designated, or detailed.

HQ-7/FM-80/FM-90 / CSA-4 Sino-Crotale Missile Design

The HQ-7 Sino-Crotale round on display (via Chinese Internet).

Above, below: HQ-7B/FM-90 Sino-Crotale round on display (image Zhenguan Studio © 2010, Air Power Australia).

The 84 kg mass R440 Crotale missile round design is similar in configuration and performance to the Soviet/Russian built NIEMI 9K33M Osa/Romb / SA-8 Gecko and Almaz-Antey/Kupol 9K331M/M1 Tor M/M1 SA-15B/C Gauntlet rounds, sharing a canard control airframe with a nose mounted proximity fuse and tail mounted uplink and transponder antennas.

Crotale subsystem schematic and velocity profile[1]

The R440 nose section is fitted with either an infrared proximity fuse, or a Thomson-CSF FPE pulse-Doppler X-band radar proximity fuze standard in naval variants, with both equipped with a backup impact fuse. The proximity fuses are typically armed 350 m prior  to estimated impact. The nose canard controls are driven in the pitch/yaw axes by an actuator package in the nose. The nose section includes the battery, power supply and autopilot module.

The centre fuselage carries the 15 kg directional fragmentation warhead which has a lethal radius of 8 metres, producing fragments with a velocity of 2,300 metres/sec. The warhead arms 2.2 sec after launch.

The aft centre fuselage houses the SNPE Lens III solid rocket motor with ~25 kg of propellant, the motor exhausts through a cylindrical exhaust duct to the tail nozzle. The motor impulse is sufficient to accelerate the round to 750 metres/sec in 2.3 seconds.

The tail section contains the roll control actuator, the Ku-band transponder beacon and antenna, the uplink receiver and antenna, and launch tube umbilical interface. Cited transponder types are the Thomson-CSF Stresa with 8 km range in early missiles, and the solid state Thomson-CSF RTKu M with 10+ km range in later missile builds.

Cited missile performance varies across sources. The single shot kill probability is claimed to be 80 percent to 90 percent, rising to 96 percent for a two round salvo. Effectiveness varies, as with all missiles in this class, on target velocity and engagement geometry, with claims that the baseline missile has successfully killed slow moving targets at 14.6 kilometres, considerably more than the cited range for fast jet targets. Two round salvoes have a 2.5 second separation between launches.

Schematic of Crotale guidance system [1].

Crotale R440 Kinematic Performance
Range [km]
Flight Duration [sec]
Load Factor [G]

There have been to date no disclosures on specific design changes made to the R440 missile design in reverse engineering it into the HQ-7/HHQ-7. The CPMIEC FM-90 brochure indicates at best incremental improvements against the baseline FM-80, these likely being in improved rocket propellant, improved flight control algorithms, and the previously discussed improvements to the radar suite. Data processing improvements in the FM-90 provide the ability to track 24 targets concurrently.

Above, below: detail of TELAR turret with four missile tubes loaded (Zhenguan Studio, © 2010 Air Power Australia).

Above, launch from P4R TELAR; below: launch from FM-90 TELAR (via Chinese Internet).

Production and Exports

While the HQ-7, HHQ-7, FM-80 and FM-90 have appeared prominently in PLA media, exact numbers on production and operational deployments remain scarce. Unlike strategic SAM systems which tend to be tied to fixed operational bases and can be easily counted, highly mobile point defence systems like the HQ-7 series are difficult to locate, and easy to hide. All indications at this stage are the the HQ-7 family systems are the principal point defence weapon used by PLA Army, PLA-AF and PLA-N units.

There is some evidence that the FM-80 was exported to Iran, but numbers have never been disclosed.

HQ-7/FM-80/FM-90 / CSA-4 Sino-Crotale Technical Data

HQ-7 [Thomson CSF R440 Crotale] Specifications
Length 2.89 m
Diameter 0.15 m
Wing span 0.54 m
Launch weight 84 kg
Propulsion solid propellant rocket motor
Guidance command link
Warhead 15 kg HE fragmentation with contact and proximity fuzing
Max speed 750 m/s
Maximum range >10 km
Minimum range
500 m
Max effective altitude 5,000-5,500 m (depending upon target velocity)
Min effective altitude 15 m
Reaction time, sec 6.5
Reload time 2 min (full 4-round load)
Single-Shot Pk
Engagement Radar Thomson-CSF Ku-band monopulse radar
Detection range
18.5 km
FM-90 Specifications (CNPMIEC)
Effective Range
ASM Target 600 m/s
700 - 7,000 m
Cruise Missile Target 300 m/s
700 - 11,000 m
Aircraft Target
700 - 12,000 m
Helicopter Target
700 - 15,000 m
Effective Altitude
ASM Target 600 m/s 30 - 3,000 m
Cruise Missile Target 300 m/s 30 - 6,000 m
Aircraft/Helicopter Target
30 - 6,000 m
Single Shot Pk
Radar System
Maximum Detection Range RCS=0.1 m2
20 km
Maximum Tracking Range RCS=0.1 m2 18 km
Concurrent Target Detection Qty
Concurrent Target Tracking Qty 24
Fire Control Channels
Reaction Time
6.5 to 10.5 sec
Missile Maximum Velocity
930 m/s
Missile Maximum load Factor
35 G

HQ-7/FM-80/FM-90 / CSA-4 Sino-Crotale Battery Components

HQ-7/FM-80 Battery Components
TELAR (2-3)
Self Propelled Transporter Erector Launcher P4R
Self Propelled Engagement Radar
Transporter / Transloader / Crane

HQ-7B/FM-90 Sino-Crotale TELAR

HQ-7B/FM-90 TELAR on parade in 2009 (via Chinese Internet).

HQ-7B/FM-90 TELAR on parade in 2009 (via Chinese Internet).

HQ-7B/FM-90 TELAR on parade in 2009 (via Chinese Internet).

HQ-7B/FM-90 TELAR stowed (via Chinese Internet).

HQ-7B/FM-90 TELAR (image Zhenguan Studio © 2010, Air Power Australia).

HQ-7B/FM-90 TELAR (image Zhenguan Studio © 2010, Air Power Australia).

FM-90 Crotale TELAR display model at Zhuhai, 2008. The engagement radar appears to be identical to the earlier FM-80 configuration (image © 2009, Zhenguan Studio).

HQ-7/FM-80 Thomson-Hotchkiss P4R Sino-Crotale TELAR

The earlier self propelled HQ-7/FM-80 variants employ a reverse engineered variant of the original Thomson-Hotchkiss P4R electrically driven armoured chassis which weighs in at 32,965 lb / 14,950 kg (via Chinese internet).

HQ-7 Sino-Crotale on cloned Thomson-Hotchkiss P4R chassis (via Chinese internet).

HQ-7 Sino-Crotale Towed TELAR

Above, below: Towed HQ-7 TELAR on display at Datangshan (Zhenguan Studio, © 2010 Air Power Australia).

Above, below: Towed HQ-7 TELAR on parade (via Chinese Internet).

HQ-7B/FM-90 Sino-Crotale ACU Self Propelled Acquisition Radar

FM-90 ACU Sino-Crotale acquisition radar. The system employs a planar array with a boresighted IFF array (via Chinese Internet).

FM-90 Crotale acquisition radar display model at Zhuhai, 2008. The acquisition radar uses a planar array with a boresighted IFF array (image © 2009, Zhenguan Studio).

FM-90 ACU (Zhenguan Studio, © 2010 Air Power Australia).

HQ-7/FM-80 Sino-Crotale ACU Self Propelled Acquisition Radar

HQ-7/FM-80 acquisition radar deployed on the P4R vehicle (via Chinese Internet).

HQ-7/FM-80 acquisition radar deployed on the P4R vehicle (via Chinese Internet).

HQ-7/FM-80 acquisition radar stowed on the P4R vehicle (via Chinese Internet).

Hybrid acquisition radar vehicle. This system combines the FM-80/HQ-7 radar with the FM-90/HQ-7B 6 x 6 vehicle (via Chinese Internet).

HHQ-7/FM-80(N)/FM-90(N) Naval Sino-Crotale

HHQ-7 launch (via Chinese Internet).

HHQ-7 launcher (via Chinese Internet).

HHQ-7 launcher, unloaded (via Chinese Internet).

Reloading a HHQ-7 launcher (via Chinese Internet).

Type 345 HHQ-7 Naval Sino-Crotale engagement radar (image © 2009, Zhenguan Studio).


  1. Crotale: A Missile Defense System against Supersonic Low-Level Air Attack, International Defense Review 1/1970, Interavia S.A.
  2. H. le Sueur, Design Philosophy of the Crotale AA System, International Defense Review - Air Defence Systems, Special Series, 1976, Interavia S.A.
  3. Crotale in Service: organizational maintenance of a missile system, International Defense Review 2/1973, Interavia S.A.
  4. Crotale NG Multi-Mission Air Defense Missile System, France, army-technology.com, Net Resources International, URI: http://www.army-technology.com/projects/crotale/
  5. CNPMIEC HQ-7 (FM-80) and FM-90 surface-to-air missile systems (China), Land systems - Air defence - Missiles, Janes, URI: http://www.janes.com/.../CNPMIEC-HQ-7-FM-80-and-FM-90-surface-to-air-missile-systems-China.html
  6. Line artwork and cited text  © 1970 - 1976, Interavia S.A.; reproduced in accordance with 17 U.S.C. §107, this  material is distributed for non-profit research and educational purposes only.

Technical Report APA-TR-2010-0901

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