Denel Rooivalk

Modern Aviation, South Africa, , , , , ,

South African Flag South Africa (1990)
Combat Support Helicopter – 12 Built

Rooivalk Mk1 with full traditional weapons loadout. Visible is the MISTRAL ATAM launcher, M159 rocket launcher pod, ZT-6 Mokopa ATGM and GIAT 20 mm F2 duel feed cannon. Source DENEL.

The Rooivalk (Red Kestrel) Combat Support Helicopter (CSH) is considered by many as one of the most advanced weapon systems produced by the South African defense industry. It was designed and developed for the hot, humid, and dusty Southern African battlespace based on the lessons learned during the South African Border War (1966-1989) to operate in a high-intensity conventional war. According to the then Minister of Defence, Mr. Joe Modise (1994-1996), the Rooivalk represents a combat helicopter of world-class standard. The Rooivalk Mk1 allows the South African Air Force (SAAF) the needed flexibility to help maintain the country’s national security interest and project force where required, such as in the Democratic Republic of the Congo.

Development

With the South African Border War (1966-1989) operations shifting from low intensity to a high-intensity conventional war in 1985, the South African Defence Force’s (SADF) need for a dedicated attack helicopter capable of defeating enemy armor became paramount. South Africa had also become subject of the United Nations Security Council Resolution 418 on 4 November 1977, which imposed an arms embargo. This isolation would lead to South Africa having to develop an attack helicopter, as none could be sourced internationally (if the need ever arose).

The Atlas Aircraft Corporation, a division of the Armaments Corporation of South Africa (ARMSCOR), not only provided support for SAAF aircraft but also gained significant experience upgrading the SAAF Mirage IIIs in the 1970s. A project study was undertaken to come up with a workable configuration in 1976/8, which placed Atlas in the position to make a helicopter industrialization program. A significant point of debate was whether a small or large helicopter would be best. The latter would win out the subjective assessment, and objective operational analysis clearly showed a light helicopter would lack the range, payload, and survivability required in a high threat environment. The requirements for an attack helicopter included: survival in a high-threat regime, commonality with the existing medium transport helicopter fleet (Oryx/Puma), quick response to the mission task, day and night operability, low pilot workload, a very accurate navigation suite, simple “in-the-field” maintenance, an operational lifespan of 30 years, the ability to come quickly under existing Army command, control and communications systems, be operable in the “‘operational ”window’ (5-15 m above the terrain) for 95% of its lifetime, long-endurance capability, ability to ferry great distances and be built within the existing industrial infrastructure of South Africa. The future attack helicopter would place speed and maneuverability above protection to fulfill the prime objectives of mission success with maximum survival chance for both crew and aircraft.

When the requirement for an attack helicopter came to light, funds were made available to the Council for Scientific and Industrial Research (CSIR) to conduct a feasibility study. A signed contract with the SAAF in 1981 led to the development of the Alpha XH-1 prototype, which was based on the French Aérospatiale SA 326B Alouette III helicopter. The purpose of the Alpha XH-1 was to serve as a learning and capacity-building platform for South African engineers, supporting industries as well as testing various concepts and systems. This development resulted in much of the components, such as the engine, gearbox, and rotor systems, being produced in South Africa. Unlike the Alouette III, the prototype had a semi-monocoque airframe. It featured a GAI Rattler 20 mm cannon on a steerable turret under the aircraft’s nose, controlled by the weapons officer’s Kukri helmet-mounted sight. The Alpha XH-1 was never regarded as anything more than a test platform for hardware development. The Alpha XH-1 flew for the first time on 2 February 1985. It flew only a few times, as the main Attack Helicopter project had surpassed its need. The XH-1 was revealed to the public in 1986.

Meanwhile, Atlas Aircraft Corporation continued with its helicopter industrialization program to build capacity to provide more critical components for the Alouette family and Aérospatiale SA330 Puma helicopters in service with the SAAF. Further development of systems, such as avionics and weapons, required testing, which resulted in the purchase of two Puma 330Js which would serve as testbeds to support parallel development activities. The first of these helicopter’s, Experimental Test Platform 1 (XTP-1), also known as Puma J1, flew in 1986 and featured locally developed avionics and weapon systems, as well as a fully configured flight test engineering station in the cabin that recorded test parameters, as well as the ability to vary several input flight parameters in the development of higher mode autopilot functions. Also included were cockpit workload assessments during simulated anti-tank missions and aerodynamic effects of the stub-wings through the flight envelope. The XTP-1 was revealed to the public in 1987.

 

The Puma J2 loaded with V3 air-to-air missiles, ZT3 anti-tank missiles, and fitted with a belly-mounted 20 mm cannon. Courtesy of: Rooivalk – a legend in the making

The second Puma J, J2, was similarly configured as J1 and flew shortly after J1. J1 was mainly used as the test platform for systems development, and J2 was used to test the weapon systems with actual weapons firing. Extensive testing was carried out on the blast effect of the ZT3 anti-tank missile and recoil force of firing the 20 mm cannon, aerodynamic interaction, and drag between the various mounted weapons, resonance, thermal dissipation, and power consumption. Both Puma Js featured stub-wings mounted on the cabin sides, which carried two 18 round 68 mm rocket pods, two four-tube ZT3 ATGM launchers, in addition to the ventral mounted turret with a 20 mm GA-1 canon linked to the weapon officer’s helmet-mounted sight. Two missile tests were conducted. The first, in December 1988, at the St Lucia test range, was meant to determine the blast effect of the ZT3 missile on the helicopter’s tail boom and the accuracy of the weapons and supporting systems. Of note is the accuracy of the ZT3 anti-tank missile, which hit a stationary target 5km away being just 450 mm off the target center. The second test occurred in 1989 and involved a combination of the 20 mm cannon, 68 mm rockets, and ZT3 missiles in determining the post-launch maneuvers and different types of operations.

In parallel to the Rooivalk development, the Medium Transport Helicopter (MTH) requirement was also being industrialized, and Atlas was being set up to manufacture common parts for both Oryx and Rooivalk, such as the main rotor and tail rotor blades, the full transmission system including gearboxes and engines, and various subsystems to the point where the Oryx, as an upgrade to the Puma, was born based on the Super Puma dynamics

The Rooivalk’s development began under the project name Chickadee in 1984, which became Impose as a later project name. Much of the technologies developed for the XTP-1 would find their way to the Rooivalk eXperimental Development Model (XDM). Its primary purpose was to test the aircraft dynamics, mechanical, aerodynamic, and structural design, flight performance, and to do weapons carriage clearance. The XDM was used in the first phase testing of the dynamic components, which included the engine, air intake system, propulsion system controls, lubrication, and cooling. It was suspended in tie town jigs and repeatedly subjected to startup, shutdown, and transient system operation, with the first test commencing on 21st December 1989. The XDM was rolled out on 15 January 1990, after nearly four years of construction. It flew for the first time on 11 February 1990, as part of its 20 hour endurance testing. By May 1992, it had amassed 180 flying hours. It was also during this time that the horizontal and vertical stabilizers were finalized in their optimized form. The vertical tail configuration is designed for high-speed flight and to optimize lateral stability and low-speed responsive yaw control. The XDM can be distinguished from the other airframes by the rounded ammo bin aft of the cannon, and the exhaust was initially without infra-red suppressors, although, later in the development program, the XDM was fitted with a set of development IR suppressors.

The XDM during the tie-down jig testing. Courtesy of: Rooivalk – a Legend in the Making

The contract for the Advanced Development Model (ADM) was placed in 1988, completed in 1992, with its first phase flight on 22 May 1992. The ADM was used to verify the avionics design and implementation, weapons development, and integration platform. The traditional instruments were replaced by three multi-function displays (MFD), and the avionics system proved to minimize the aircrew workload significantly. The Rooivalk ADM would be the first-ever attack helicopter to fly with an MFD” “glass cockpit”. The ADM featured the MIL-STD-1553B digital databus system and was equipped with ZT3 Ingwe ATGM missiles, as well as a 20 mm cannon mounted to a TC-20 chin turret. The second phase of testing commenced on 23rd July and lasted until 4th December 1992 and involved in-flight operation of the Integrated Management System, the Health Monitoring System, the Automatic Flight Control System, and the Communication System. The third phase of testing was focus on the weapon systems and included the nose-mounted Main Sight System (MSS), 20 mm cannon in August 1993, and ZT3 anti-tank missile in March 1994. Both weapons systems were successfully tested.

XDM again during the subsequent flight trials program. Courtesy of: Rooivalk – a Legend in the Making

The ADM made its international debut at the Dubai air show in 1993, followed by the Malaysia air show in 1993. In 1994, the ADM was on display at the Farnborough International Air show in England. With potential international exports in mind, the Rooivalk was developed according to US military requirements and standards, which would only require small adjustments to make it compatible with US weapons systems such as the Hellfire ATGM. Meanwhile, the SAAF was contemplating an order of 16 Rooivalks with an updated User Requirement Specification which specified a more powerful cannon and longer-range missiles. Although 36 Rooivalks were envisaged to complete three squadrons, cuts to the defense budget and a change in the defense force strategy resulted in only 12 being ordered.

The Engineering Development Model (EDM) was developed as a platform to incorporate lessons learned from the XDM & ADM, to incorporate the SAAF’s updated User Requirement, as well as for doctrine and mission development. Design and development began in March 1993. The completed aircraft rolled out on 17th November 1996 and a flight was presented on 17th February 1997 by Denel. The purpose of the EDM was to qualify the avionics, weapon systems, airframe, and airborne systems before serial production could commence. Additionally, the EDM was used to refine the required logistical support. With the EDM, the ammo bins were moved to each side of the cockpit and the infra-red suppressor exhaust was directed upwards into the main rotor blades to dissipate the heat more efficiently. Additionally, the EDM saw many structural changes, as well as weight reduction. It represented the beginning of the Rooivalk assembly line.

The Rooivalk ADM international debut during the Dubai 1993 air show. Screengrab from Paratus Magazine. Original photo by S. Basch
EDM 70 mm rockets loading (left) and firing (right) tests. Courtesy of: Rooivalk – a legend in the making

In 1994, the Rooivalk was entered into the UK Ministry of Defence (MoD) tender for an attack helicopter. An audit by the MoD in March 1994 allowed Denel Aviation to submit its Invitation to Tender (ITT). Although ultimately unsuccessful, the experience was invaluable for future tender processes.

On 2nd August 2005, Rooivalk 679 sustained damage when it suffered a hard landing testing a newly installed autopilot. The main rotors were damaged, and the tail boom broke off. The Rooivalk’s design philosophy of protecting the crew succeeded, as neither were seriously injured. It was deemed uneconomical at the time to repair and it was subsequently stripped of usable parts. In 2016, Denel was still in talks with the SAAF to make use of Rooivalk 679 as a prototype platform for further development. The full order of 12 aircraft was completed by 2004. The total cost is estimated at R6.2 billion in 2015 for the full development activity and the production run of 12 aircraft.

The first SAAF Rooivalk was delivered on 7th May 1998 and was subsequently upgraded in blocks, starting with 1A, up to its current 1F, which is referred to as Mk1 baseline. The SAAF would only take delivery of six fully operational and military certified Rooivalk MK1s in April 2011. The Rooivalk Mk1 included 130 modifications, such as improved sighting and targeting system, communications systems, gearboxes, self-protection, the ability to fire the Mokopa ATGM and improved reliability of the 20 mm cannon. Additionally, fuel drop tanks were added which became invaluable for self-deployment to the DRC. The remaining five aircraft entered service by March 2013.

In 2015, the South African Department of Defence was considering restarting the Rooivalk manufacturing. The acting chief executive of Denel, Zwelakhe Nshepe, stated in 2017 that the Rooivalk MK1 would hopefully lead to the next generation Rooivalk MK2, which would be aimed at the export market. It features better sights, more firepower, a higher payload, and increased survivability. It was noted that a minimum of 75 airframes would need to be ordered for the project to be financially viable. At the time, Brazil, Egypt, India, and Nigeria were identified as potential target markets.

Denel has approved the Rooivalk Mk1.1 upgrades and was negotiating with the SAAF on the matter as a midlife upgrade, already due in 2016.

South Africa is the only user of the Rooivalk Mk1 CSH, which is assigned to 16 Squadron at Bloemspruit Air Force Base in Bloemfontein.

Design Features

The Rooivalk’s mission was envisaged according to the role at the time of an armed helicopter in a conventional war. This included operations with mechanised forces, deep penetration into enemy territory, air defence suppression, counter helicopter and anti-armor operations, counter-air operations against airbases, helicopter escort missions, maritime patrol, and reconnaissance. Based on those requirements, the Rooivalk design philosophy centred around four pillars, namely not to be seen, if seen not to be hit, if hit to sustain flight and if the flight could not be maintained the pilots had to survive the crash.

Performance

The Rooivalk was designed to exceed the demands required during the first 24 hours of a high-intensity war while in unfriendly territory. The Rooivalk is powered by two Turbomeca Makila 1K2 turboshaft engines which produce 1845 shp (246 shp/t).

It has an empty weight of 5910 kg and a max take-off weight of 8750 kg, which equals a carrying capacity of 2840 kg. Its typical mission weight is 7500 kg.

Its broad performance envelope includes operating in temperatures of between -35° C to +50° C, being able to take-off and land between -3000 ft to +19200 ft, and have a flight altitude of 20000 ft. Its hover over ground effect is 5,029 m, which is comparatively high compared to the AH-64 Apache (3,866 m), Mi-28 Havoc (3,600 m), Ka-50 Kamov (3,600 m), and Eurocopter Tiger (3,200 m). At mission weight, it has a cruising speed of 278 km/h and a top speed of 309 km/h. It can fly sideways at 92 km/h. At sea level, it can ascend 670 m a minute (11 m/s) with a maximum hovering ceiling of 5,545 m and a service ceiling of 6,095 m.

The Rooivalk has a minimum endurance of 216 minutes and 412 minutes with external fuel drop tanks, allowing it to self-deploy some 1260 km. Its combat radius (when fully armed) is 740 km with reserve fuel.

The airframe is rated at +3.5/-0.5 g.

The Rooivalk ranks among the top helicopters with regards to cruise speed, operational range, rate of climb, weapons loadout and power to weight, which are all essential during combat operations.

Aircraft Layout

The airframe has a length of 16.39 m (nose to the rear wheel), height of 5.19 m (ground to rotor head fairing) and width of 6.95 m (from either side of the stub-wings). The diameter of the four composite blade main rotor is 15.58 m and expands to 18.73 m when rotating. The tail rotor is 3.05 m wide.

The fuselage consists primarily of aluminium alloy to save weight and access doors hinged to the central I-beam and made of composite material that allow easy access to the interior.

The aircrew stations are placed in a step, which reduces the glare from the sun associated with tandem designs. Access to either side of each station is via upward hinged flat bulletproof windows. The aircrew stations are ergonomically designed to reduce aircrew workload and fatigue, which enhances endurance and battlefield awareness. The aircrew station for the pilot seated in the rear and Weapon Systems Officer (WSO) seat in front make use of Hands-On Collective and Stick (HOCAS) controls. The dashboard features three MFD displays, which are vital, as the Rooivalk would spend 90% of its time between 5 – 15 m off the ground during a combat mission.

The engines are fitted alongside the main gearbox, with the rear output shaft aligned to drive the gearbox from the rear. The gearbox itself is mounted on a tuned beam (vibration Isolation System) to minimise vibration on the airframe. The engine air intakes are fitted with a highly efficient particle separator (to keep dust and debris out) with a 97% efficiency against particles of 10 microns. Air from the engines is directed upwards through infra-red suppressors into the rotor blade downwash to disperse the heat and reduce its Infra-Red (IR) signature.

The Rooivalk has three internal fuel tanks located in the middle of the airframe, under the stub-wings centre section, each with a 480 kg (total 1440kg) carrying capacity. It makes use of Jet A-1 type fuel.

The stub-wings are fitted on either side of the airframe and have a straight rectangular shape.

The landing gear is of fixed design and consists of two forward wheels on the forward section of the airframe and a tailwheel. The wheelbase is 11.77 m (38ft 7in) and the wheel track 3 m (9ft 10in).

Endurance and Logistics

During the South African Border War, the SAAF made extensive use of Alouette III and Puma helicopters, gaining valuable operational and logistical experience. The Rooivalk was subsequently designed to operate for extended periods with minimal support and maintenance in the field with basic spares which are transportable via Oryx helicopter. The airframe has many large access panels which make access simple, as no tools are needed. The stub-wings and cowling (cover over the engine) are functional as working stations, and no ground support equipment is needed. It can be maintained with a ground crew of four in the field with spares that can be flown in an Oryx. The ground crew’s task is made easier with onboard test functions and line replacement units. The Rooivalk’s overall design also incorporated easy refuelling and re-arming. The engine features highly efficient sand filters which help reduce wear and tear and extends service life.

Avionics and Weapon System

The Rooivalk makes use of the advanced international digital Military Standard (MIL-STD-1760B) Class 2 weapons station and MIL-STD-1553B avionics system. The systems allow total mission modes, target acquisition, flight control, health and usage monitoring, communication, threat detection, and control of flight and fuel.

The avionic system is fully digital and incorporates night vision goggle compatible glass cockpit technology for low light night vision. This allows accurate navigation, pre-programmable tactical flight plans with moving digital map and flight data projection on two liquid crystal multi-function display. The multi-function displays allow the aircrew to switch between navigation, flight control, weapons control, threat warning and imagery from the sensors when required.

Flight control avionics consists of a duplex four-axis digital automatic flight control system. The latter is coupled with ring laser gyros with navigation and position input from a radar altimeter, eight-channel GPS, Doppler velocity sensor, magnetometer heading sensor, air data unit and an omnidirectional airspeed sensor. All of these systems are linked to a dual redundant navigational computer.

The autopilot system makes use of an eight-channel Global Positioning System (GPS) and Inertial Navigation System (INS). The system allows for normal as well as higher mode linkage to the avionics and weapons system. The one-touch feature for auto-hover, altitude hold, follow a planned route and target orientation is based on the main sighting system. The former two features allow the aircrew to recover from vertigo which could occur during night time low-level tactical operations or poor weather.

 

WSO cockpit layout illustration, Courtesy of Rooivalk – a Legend in the Making

The nose-mounted gyro-stabilised sensor turret housing with auto-tracking contains the target acquisition designation sight known as the NightOwl system. The system was developed by Société de Fabrication d’Instruments de Mesure (SFIM), which was absorbed by the Société d’Applications Générales de l’Électricité et de la Mécanique (SAGEM) in 1999/2000. It consists of 3-FOV FLIR with automatic tracking, LLTV and laser rangefinder and designator. The three fields of view, which include thermal and low light displays, have recording function with playback facilities and sight cueing. This allows for pop-up missile engagements based on target location recorded during high threat situations. The missile command and control system is integrated with the avionic system, which provides continuous navigational updates, flight control handover and weapons computing parameters. The weapons system additionally provides weapons and stores management. The aircrew’s helmet-mounted sight displays both flight and weapon data and can both cue the turret-mounted GI2 20 mm cannon and other armaments.

All armament can be used by either the pilot or WSO, although the use of the Mokopa could be laser designated by sight or from an external source. The pilot can, for example, use the cannon and rockets to suppress enemy fire while the WSO fires the Mokopa. The pilot and WSO cue the primary sight via their helmet sight and thereby show the other a target of opportunity or imminent threat. The fire control system (FCS) allows the flight crew to pop up from behind cover, scan the surrounding area, drop back down and identify targets via video cassette recording playback function, select targets and attack or relay target information to another Rooivalk or ground forces via secure data link.

Cockpit Layout

Both cockpits are equipped with two main color MFD with multi-function push buttons for displaying sight images, maps or information at high resolution. There is also a secondary control and display interface unit onboard system.

Helmet Mounted Sight Display

The helmet-mounted sight display (HMSD), or TopOwl, incorporates an integrated measurement system to control the weapons. The helmet makes use of electromagnetic tracking which allows the pilot or WSO to look at a target, thereby directing the weapons on the target. The helmet has an integrated Generation IV image intensifier and FLIR capability which can be switched between with the push of a button. The TopOwl HMSD was developed by Sextant Avionique, which later merged with Thales. The pilot night vision system (PNVS) is located on the top of the nose of the Rooivalk and was developed by Cumulus, which was absorbed by Denel Optronics, and later Cassidian Optronics.

Both helmets have two monocular display modules with integrated CRT which can project Heads-Up Display (HUD) information as well as video images into the crew member’s line of sight. This allows them to retain access to their HMDS information even when using NVGs. The pilot can access real-time imagery from the PNVS while flying NOE.

HMSD symbol legend is projected onto the crewmembers visors. Courtesy of: Rooivalk – a Legend in the making

Communication Systems

The Rooivalk makes use of pre-programmable secure voice, image and data communication for enhanced battlefield communication. The communications suite consists of a Reutech Radar Systems ACR500 transceiver and AC500 controller. The suite includes two dual-frequency hopping Very High Frequency (VHF) and Ultra High Frequency (UHF) transceivers with frequency modulation (FM), amplitude modulation (AM) and digital speech processing, and one High Frequency (HF) radio with secure voice and data channels for Nap of the Earth (NOE) flying. Also included is an Identify Friend or Foe (IFF) transponder.

Main Armament

During its development, the Rooivalk’s weapons system allowed for a wide range of South African weapons. The layout and complement of armaments have remained generally the same. For this section, the initial Rooivalk ADM (1994) will be unpacked, followed by the present (2020) Rooivalk Mk1.

The Rooivalk ADM’s stub-wings each had three weapons pylons. One was on the stub-wingtips for an air to air missile and two underneath. The weapons pylons could be arranged according to mission requirements.

Under the Rooivalk ADM’s nose was a TC-20 hydraulically driven mount for a GA1 20 x 84 mm single feed Rattler cannon. It had a muzzle speed of 720 m/s and a fire rate of 600-750 rpm. Ammunition consisted of 20 x 82 mm HE-I, HEI-T, AP-HEI. Some 400 rounds were carried in an ammunition magazine located under the weapons officer’s station.

The air to air missile was a single South African supersonic passive heat-seeking V3B Kukri with proportional navigation. It has a maximum speed of 1,870 km/h, a range of 5 km, 40 g tolerance with a flight duration of 25 sec. It is the first successful helmet slaved missile in the world.

Rooivalk ADM on display in Farnborough International Airshow, United Kingdom, 1994. Visible is the V3B Kukri, HR-68 rocket launcher and 68 mm SNEB FFAR, ZT-3 Swift ATGM, external 750-litre fuel drop tank and GA-1 20 mm single feed Rattler cannon. With permission from Aviation Central.
The ZT series of ATGM missiles. ZT-3 Swift (bottom), ZT-35 Ingwe with active proximity fuse (middle) and contact probe fuse (top). Screengrab from PARATUS Magazine, April 1994.

The HR-68 rocket launcher pod carries 18 x 68 mm Societe Nouvelle des Etablissements Edgar Brandt (SNEB) unguided Folding Fin Aerial Rocket (FFAR). The rocket is powered by a 31 kg rocket motor which gives a maximum velocity of 450 m/s, and slant range is 1600 m, with an accuracy of 2 mils.

The quarto missile tube for either the ZT-3 Swift or ZT-35 Ingwe laser beam riding anti-tank guided missile (ATGM) have a 4 km and 5 km standoff range, respectively. Both are equipped with a high explosive anti-tank warhead (HEAT). The ZT-3 Swift can penetrate 650 mm of rolled homogenous armor at zero degrees and the ZT-35 Ingwe 1000 mm (with active proximity fuse). The latter is also equipped with a tandem warhead to defeat explosive reactive armor (ERA).

The Rooivalk Mk1 weapons compliment differs significantly from the ADMs. The stub-wings retained the three weapons pylons, however, the stub-wingtip pylon has moved under the wing.

For the Rooivalk Mk1, the cannon was changed to the battle-proven GI2 20 mm (mounted on the Ratel 20 Infantry Combat Vehicle), with a new chin mounting system, which includes a hydraulic-driven elevation and azimuth drive control. It has a fire rate of 720-740 rounds per minute. Its operating envelope is -110 to +110 degrees in azimuth and -55 to + 15 degrees elevation. Reaction time is 1.8 sec from selection to firing at 60 degrees traverse at -45 elevation. It has a slew rate of 90˚/sec. The cannon has two modes of operation, namely quick reaction and accurate mode. The former entails using the helmet-mounted sight for slewing the cannon on target, while the latter makes use of the nose-mounted sight.

TC-20 hydraulically driven mount with a GI2 20 mm cannon (left), ammunition feed belt with APCT rounds (right). Source Denel

The cannon rounds are kept in two sponsons on either side of the forward fuselage and fed into the cannon via a dual-feed system from inside the turret shroud. The primary ammunition used is 20 x 139 mm (HS820) High Explosive Incendiary (HE-I) and Armor Piercing Core Tracer (APCT). The HE-I, which travels at 1050 m/s, is effective up to 2 km. The APCT rounds travel at 1300 m/s and are considered effective up to 1 km and can penetrate 15 mm of RHA at 2 km. The auto-feed mechanism of the 20 mm gun allows to immediately change between the two different ammunition belts (350 rounds each) feeding into the cannon with the flip of a switch. This weapon was selected for ease of logistics. However, problems were encountered with the weapon, as the shockwave from firing would disturb the sight mirrors. This problem was fixed in the Mk1 upgrade.

The M159 rocket launcher pod carries 19×70 mm Forges Zeebrugge (FZ) unguided FFAR. The rocket is powered by a 31 kg rocket motor which gives a maximum velocity of 1250 m/s, and slant range is 9.1 km. The rocket can be fired individually, in pairs or sets of four and the articulated pylons raised or lowered for optimum trajectory. The FZ90 can carry a variety of warheads, which include High Explosive General Purpose (HEGP), Inert Practice, Flash Signature, High Explosive Armor Piercing (HEAP), Multidart and Flechette. Recently, the Rooivalk Mk1 also test-fired the FZ laser-guided rocket variant which enhances the accuracy to less than 1 m for a target at 4-5 km. Given the high cost of laser-guided ATGMs, these FZ laser-guided rockets can be a suitable compromise for a defence force on a budget not facing MBTs.

Originally designed for use on the Ratel ZT3 ICV and successfully incorporated into the Rooivalk ADM, the ZT-35 missile is too slow to be used on an aircraft. Taking 25 sec to reach 4 km exposes the Rooivalk to enemy air defence. Studies showed that exposure over 10 sec dramatically decreases a helicopter’s survivability. The ZT-35 missile has been replaced by the state-of-the-art, long-range, precision-guided 178 mm ZT-6 Mokopa (Black Mamba).

Designed and developed by Denel Dynamics in 1996, the Mokopa was initially designed as the primary anti-armor weapon for the Rooivalk. It has, however, evolved into a multi-purpose missile applicable to both conventional and asymmetrical scenarios. The missile can be fired in the traditional direct lock-on before launch (LOBL), or lock-on after launch (LOAL). With LOAL, the missile flies in the general direction of the target until it detects a designated laser beam illuminating a target within the last eight seconds of flight. The Rooivalk can also launch several Mokopa missiles in rapid-fire mode (eight seconds apart) and designate several targets using different laser codes. A remote laser targeting by another Rooivalk or ground-based designator can also be used to illuminate targets which the Mokopa will then guide towards. Rapid-fire can also be synchronised with remote lasers, each illuminating individual targets, which each Mokopa will then be allocated to and guide towards.

Mokopa and Ingwe size comparison. Source unknown

Making use of semi-active laser guidance, the Mokopa is of a modular design and can carry a penetration, fragmentation, or anti-armor warhead. Unlike the ZT3 Ingwe, the Mokopa is designed to approach a target, such as MBTs, at an angle from above, to hit where it is least armored. The tandem HEAT warhead, which can defeat ERA, is capable of penetrating 1350 mm of RHA armor at zero degrees. A High Explosives (HE) fragmentation warhead has also been developed, allowing the Mokopa to engage soft\lightly armored targets with devastating effect. Making use of a solid-fuel composite rocket motor with a slow-burning rate, it can engage targets up to 10 km away with a circular error probable of 30 cm. The first air-launched test occurred in 1999, followed by the first guided test in 2000. The Mokopa’s firing trials were completed on 21 January 2011 at the DENEL OTB test range. As a side note, the Mokopa can also is configured to make use of mmW or IIR guidance and carry multi-purpose warheads. The mmW is a true fire and forget missile which can be preprogrammed with a target’s location, to which it will guide itself after launch.

Two Mistrals in their launcher. They are carried in protective launch tubes with hinged doors which open when fired. Courtesy of: Rooivalk – a Legend in the Making

For air to air engagements, the Rooivalk Mk1 can be armed with four all aspect, fully digital Matra Mistral heat-seeking missiles. The missiles are carried on ATAM launcher pods on the outermost pylon of the stub-wings. The Mistral can be fired at targets from either the helmet-mounted sight or the main sight. The missiles have a maximum speed of 2,600 km/h, 12 g tolerance, range of 6.5 km, and carry a 3 kg HE tungsten filled warhead with detonation via laser proximity fuse.

Protection

In line with the Rooivalk design philosophy, its foremost protection lies in its agility and stealthy design. The former is achieved by a 52 per cent excess hover power for quick reaction and ability to move sideways at 93 km/h, allowing the Rooivalk to engage targets and disappear behind cover quickly. With regards to stealthy design, particular attention was paid during its development to reduce its radar, IR and noise signature. The radar signature is reduced by making use of carbon fibre and metalised fairings to shield the rotor mast and controls. The canopy surface makes use of an RF reflective material. The IR signature of the engine is reduced passively by angling the exhaust upwards into the rotor blade downwash for quicker heat dispersal. The visual signature of the fuselage only offers a 1.28 m target from the front and 4 m from the top to bottom of the rotor head. Glint is minimised by using flat and single curvature surfaces where possible. The main rotor acoustic noise is reduced by keeping the rotor tip speed low and passive measures to reduce the engine noise at the intake and exhaust. A combination of the aforementioned makes it difficult for enemies to acquire and engage the Rooivalk.

Rooivalk armoured crew seat – Sourced online

Provision was made during its design for dual redundancy of major systems, damage tolerance, and multiple load path use by avionic systems, flight and structural damage. The Rooivalk’s structure and dynamic systems have been designed to tolerate 23 mm high explosive rounds and survive direct hits from a 12.7 mm AP round and keep on working for at least 30 minutes. This allows the Rooivalk a greater chance to remain airborne and flying should it sustain damage. The self-sealing fuel tanks can also survive a direct hit from a 12.7 mm AP round without exploding. The aircrew stations are armoured against 12.7 mm AP rounds, and the seats are crashworthy, which minimizes the likelihood of injury to the crew if a crash occurs within its design performance. The Rooivalk’s crashworthy airframe is designed to withstand a sink rate of 11 m/s. and the tailwheel and landing gears designed to absorb the energy of a sink rate up to 6 m/s.

It is equipped with a Helicopter Electronic Warfare Self-Protection Suite (HEWSPS), which uses the Integrated Defensive Aids Suite (IDAS) from SAAB. The suite provides laser-warning, missile-approach-warning, as well as full multi-spectral detection capability for radar. Additionally, the suite allows for in-flight configuration against known threats.

The laser-warning system covers broadband laser frequency to detect, plot bearing and range for the display of the laser threats.

The radar warning system makes use of low Effective Radiated Power (ERP) pulse-Doppler radar detection from beyond radar detection range. Additionally, it provides ultra-broadband frequency coverage with high pulse density handling and instantaneous internal frequency measurement.

Once a threat is detected, the countermeasure system deploys chaff and flares from dispensers on either side of the rear fuselage to confuse incoming missile IR or radar lock. The system can also be operated manually or semi-automatically.

Rooivalk in Action

As a member of the UN and AU, South Africa is committed to peacekeeping missions in the DRC, Sudan and South Sudan. The eastern part of the Democratic Republic of the Congo (DRC) is characterized by mountainous terrain, which is plagued by rebel factions known for raping, pillaging and murdering civilians and aid workers alike. The UN Security Council resolution 2098 of 2013 and subsequent resolutions authorised the formation of a UN Force Intervention Brigade (FIB) in the DRC, with a peace enforcement mandate. The FIB consists of three infantry battalions, one artillery, one Special Forces and Reconnaissance Company, as well three Rooivalk MK1 and several Oryx helicopters. The countries that made up the UN FIB were South Africa, Tanzania, and Malawi.

Shortly after deploying to the DRC, the white-painted Rooivalks engaged in their first combat mission against M23 rebels at 17:00 on 4 November 2013. Making devastating use of their 70 mm rockets, the Rooivalks engaged rebel positions near Chanzu (close to the Rwandan border), while the Armed Forces of the Democratic Republic of the Congo (FARDC) conducted a ground assault against M23 positions with the assistance of artillery. The operation ended at 18:20, with the Rooivalks firing 38 and 17 rockets, respectively. Such was their physical and psychological impact and ground assault that the M23 rebels called an end to their 20-month long rebellion the very next day.

On 1 December 2015, several Rooivalks based in Goma (eastern DRC) were tasked with supporting a FIB attack on Islamist Allied Democratic Forces (IADF) guerrillas. The Rooivalk attack was preceded by Ukrainian Mi-25 Hind attack helicopters, but due to bad weather, this was somewhat ineffective against IADF ground positions. The Rooivalk, on the other hand, was unhampered and delivered accurate 70 mm rocket and 20 mm cannon fire.

The Rooivalk received high praise by various international defence analysts for its combat performance in the DRC, as it could operate in any weather condition which the Ukrainian Mi-25 Hind could not.

Typically, a Rooivalk flight mission in the DRC lasts two hours and involves intelligence, surveillance, target acquisition and reconnaissance (ISTAR) in addition to convoy and aircraft escort. While on a mission, it is armed with 550 x 20 mm rounds and 20 x 70 mm rockets. When engaging a target, the Rooivalk climbs rapidly and dives at its target firing rocket salvos and, if necessary, its 20 mm cannon. This method works best to breach the tree canopy foliage in the DRC.

While deployed to the DRC between 2013 and 2015, the three Rooivalks fired 199 70 mm rockets and 610  20 mm cannon rounds in anger. The following year saw a steep rise in rebel activity, with the Rooivalks firing 1200 70 mm rockets and 11,000 20 mm round. The majority of these combat engagements were against Allied Democratic Forces (ADF) during the last two weeks of December 2016.

Two SAAF Rooivalk Attack Helicopters serving as part of the United Nations Force Intervention Brigade, escorting a UN delegation in the Democratic Republic of the Congo, 2014. Source MONUSCO/Clara Padovan

Future Prospects

The Rooivalk must be considered in the context of the role for which it was developed, supporting deep raids by heliborne and parachute forces. Fighters would lack the time on station to give effective close support, whereas the ‘combat support helicopter’ could operate from a ‘helicopter administrative area’ closer to the objective, supplied by transport helicopters or aircraft. That set the requirement for good range, endurance and weapons load, as well as ruggedness and ease of support in an austere location. Also, logistics argued for maximum commonality with the Oryx medium helicopter.

The resulting Rooivalk has performed extremely well in the Democratic Republic of Congo, where it has flown armed reconnaissance, escort and close support for the Force Intervention Brigade. It has proved effective, including in poor weather conditions, and reliable, eliciting very positive comments from officers serving with the UN force in the DRC.

The Rooivalk is due for an upgrade, which would require the following changes to the aircraft: A new main sight, upgraded avionics, new computers and replacing some wiring with fiber. They are all practical and affordable. One Hensoldt Optronics Argos variant, for instance, can add a beam generator to the laser designator, allowing the use of both laser-guided and beam riding missiles, greatly expanding tactical capability. An air-to-air missile could be integrated, as could an advanced self-protection suite.

Its performance in the DRC has also brought interest by some other forces in a possible Mk2 variant, so the story of the Rooivalk may not end with the present fleet.

Helmoed-Römer Heitman – South African author, journalist, historian, military analyst and citizen-soldier.

Conclusion

Rooivalk is a highly sophisticated digital aircraft. The investment in digital-based systems provides a weapon system that is capable of achieving ultra-high assurance levels of mission accomplishment in a most demanding operational environment. Furthermore, the hazards of this environment, such as adverse weather, terrain and darkness; as well as the threats posed by the enemy, are significantly reduced because of very effective electronic enhancement. There need be no doubt that the percentage of the purchase price of Rooivalk that is attributable to avionics and electronics is money seriously well spent.

Robert Paul Jonkers – Programme Manager for the Rooivalk (1999-2004)

Videos

Rooivalk Weapons Demo https://www.youtube.com/watch?v=9_vn0gSXaKU

Rooivalk Combat Support Helicopter – SAAF 16 Squadron – Live onboard Cameras https://www.youtube.com/watch?v=8_m-S9PW5vY

Specifications

ROOIVALK CSH MK1 SPECIFICATIONS

(Typical mission loadout)
Crew 2 Fuel capacity (kg) (3 x tanks) 480
Mission weight (t) 7.5 Max. range (km) 740
Power-to-weight ratio (shp/t) 246 Engine power output (shp) 1845
Length (m) 16.39 Cannon calibre (mm) 20
Width (m) 6.95 Rockets calibre (mm) 70
Height (m) 5.19 Air to ground missiles calibre (mm) 127
Ascend rate (m/s) 11 Air to air missiles calibre (mm) 90
Max. flight altitude (ft) 20,000 Ammunition of Cannon 700
Hover over ground effect (m) 5,029 Rockets (2 x pods) 38
Cruising speed (km/h) 278 Air to ground missiles (2 x quarto rails) 8
Max. speed (km/h) 309 Air to air missiles (2 x dual pods) 4

Gallery

AH-2A – No. 678 AFB-Langebaanweg Dec 2017 – By Ed Jackson – artbyedo.com
AH-2A – No. 676 AFB-Durban Feb 2017 – By Ed Jackson – artbyedo.com

Special Thanks

The author would like to acknowledge and thank several individuals. Rob Jonkers, former Programme Manager for the Rooivalk (1999-2004), for doing quality control of the article content and providing permission to source from his book Rooivalk – a legend in the making. Also Justin Cronjé from defenceWeb, which is Africa’s leading defense news portal, for making some of their resources available. Helmoed-Römer Heitman for his contribution on the Rooivalk’s possible future.

Sources

 

 

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