Rafale of Golden Arrows and Falcons – Part 1
In September 2016, India signed an ‘Inter-governmental agreement’ for rapid delivery of 36 Rafale in a fly-away condition. So far 18 Rafales have been delivered to India in 5 batches, the most recent one being on April 21, 2021. The deliveries from Dassault Aviation are on time if not a bit earlier. The first squadron based in Ambala AFS. i.e No.17 squadron is called as the ‘Golden Arrows’. The second squadron i.e No.101 called as Falcons is being raised at Hasimara AFS. The Indian Rafales are of the F3R variant. We know Rafales are said to be in the class of 4.5 generation fighters. Let us see how the Indian Rafales are in the class of 4.5 generation. In part-1 we at Alpha Defense shall cover the structures, avionics, sensors and the cockpit in order to keep the article short. In part-2 we shall cover the engine, the armaments and the maintenance aspects.
Structural design of Rafale
On observing the aircraft, one can see it has the delta configuration and active close coupled canard which results in aerodynamic instability. This is what provides the capability of high maneuverability. On taking a look at specifications, one can see that the structure is sturdy enough to withstand high tensile forces of 11g in case of emergencies. During normal scenarios it can withstand tensile forces to the tune of ‘9g’ and compressive forces of ‘-3.6g’. The presence of canards means small decrements in lift can be achieved thereby enabling enhanced control of landing speeds. The structural aspects of all Rafale variants are more or less the same.
Signature reductions – Shaping considerations in Rafale design
Rafale is not built on the premise of stealth being its primary design factor. However the designing was carefully done to obtain low RCS and infra-red signature. The first step taken to reduce the radar siganture was reduced tail fin size. Since Rafale employs single tail fin, its sizing had to be a good tradeoff between the desired requirements of better stability, maneuverability and low signature reflection. The fuselage was reshaped in a way that a balance was achieved on radar scattering from different angles. This can be observed from the roundedness employed that facilitates scattering of incoming radar waves with a small component returned abck to source. Thereby ensuring a more or less same RCS from different angles.
Despite having riveted structures, there are no such primary surface discontinuties that can cause scattering back to the source. The dominant visible discontinuity is the air-intake attached to the main fuselage. But if we take a look, the curved nature of the interface enables radar waves from bottom to be reflected multiple times between the gap. And finally it would be emitted out to the top. There is minimal reflection to the source at bottom. The only factors contributing to a radar reflection back to source are the wings, portions of the underbelly and a small bottom projected area of the fuselage over the whole length. This can be shown as below.
The S-duct air intake helps in concealing the engine blades from radar waves. Also the use of serrated patterns as seen in above image helps in reducing frontal RCS. Most features of Rafale as to how it further reduces the signatures are not available in public domain.
Material usage in Rafale
Rafale makes extensive use of composite materials that comprises of carbon fiber based and thermoplastics. This accounts for about 70% of it’s surface area. This facilitates good reduction in radar siganture. The use of Al-Li is done in areas where weight reductions can be done without compromising thermal requirements. Use of Kevlar at nose and at wing leading edges is from thermal and strength perspective.
It is well known that the placement of antennae and various sensors too are deciding factors in the RCS of an aircraft. The various sensor locations are as shown below. Overall these are some major known reasons why Rafale has an RCS in the 0.1m2 – 1m2 class. Hence despite stealth not being the primary design factor, Rafale has impressive signature reduction methods of which the most common are known to the public. This provides the Indian Air Force Rafales a significant advantage over adversaries.
Radar and Sensors of Rafale
What provides the Rafale a considerable leap over other 4th gen fighter jets is the radar and the sensors used. Coming to the radar, Rafale boasts of the most technologically advanced AESA radar in service, which is the RBE2 AA. With a superior detection and tracking range of 200 km, this radar has the electronic scanning agility to track targets in or out of search domain. The SAR (Synthetic Aperture Radar) modes provide very high resolution ground mapping.
As a part of the Indian Specific enhancement, the radar will have Doppler Beam Sharpening (DBS) mode as well as the Non Cooperative Target Recognition (NTCR) mode
The RBE2 AA AESA enables tracking of multiple air targets for close combat and long-range interception in all weathers and even in jammed environments. Its fusion with advanced avionics facilitates real time generation of 3D maps for terrain following above unchartered terrain in blind conditions. It provides real time generation of HDR 2D ground maps for navigation updates and detection, identification and designation of ground targets. Its full compatibility with the BVRAAM Meteor provides Rafale with another arm of lethality.
The Indian specific enhancements done in this case are the Ground moving target indicator and ground moving target track (GMTI/T) modes in radar. Additionally Indian Rafales will also feature Infra-red Search and track (IRST) sensor.
Optronique Secteur Frontal (OSF) /FSO
The passive sensor system OSF provides a tele-lens picture of the target with the range measured by the incorporated laser. This kind of covert approach capability helps in interception wherein the TV picture provides early visual identification and detection of suspect manoeuvres. Since it operates in the optronic wavelengths, it is immune to radar jamming. It provides covert long-range detection and identification, high resolution multi-target angular tracking and laser range finding for air, sea and ground targets. The wavelength range is narrow and since it encompasses the visible spectrum as well, targets can be identified with a visual contact as and when required. The OSF is visible above the nose cone, below the windscreen and to the side of the refueling probe.
Electronic Warfare capabilities of Rafale
Rafale has a modular data processing unit which integrates the avionics. It hosts the flight management system, data fusion, fire control and a human-machine interface. The integrated defensive-aids system named SPECTRA is a fully internal electronic warfare system. It thereby leaves all the hardpoints available for weapons, fuel tanks or pods. SPECTRA makes use of the latest intelligence available at mission launch time and launches Supression of enemy air defence (SEAD) strikes. It helps in carrying out jamming of radars, laser and missile threats in addition to the conventional chaff and flare decoys.
SPECTRA is fully integrated into the mission system. Hence it provides threat geo-location and identification data to the data fusion process. Being fully integrated with other systems, it provides a multi-spectral threat warning capability against enemy lasers, missiles and radars. It carries out long range detection, identification and localization of threats. This will allow the IAF pilots to instantly select the most effective defensive measures. It enables a combination of radar jamming, infrared or radar decoying and evasive maneuvers.
SPECTRA has the ability to accurately locate ground targets and can take suitable decisions as to avoid them or target them using precision guided munitions. SPECTRA also enables defining and updating a threat library by the IAF with full autonomy.
The Indian Specific enhancement done is this case is Low Band Jammer (LBJ) pod with frequency band of 1-4.5 GHz and introduction of Radar Warning Receiver (RWR) from 2.5-18 GHz to 10-18 GHz.
Indian Rafales are equipped with the Thales Areos recon pod, which can be used from a high altitude stand-off distance and even at extremely low level. This recon pod is fitted with a data link which allows high resolution images to be transmitted back to military decision makers in real time. Indian Rafale features the Israeli Litening pod in order to maintain sensors commonality across all platforms. However they have optioned the TALIOS pod for a possible future integration.
Wide Information Sharing and Data Fusion
The secure high-rate data links of Indian Rafales enables sharing a common tactical picture between wingmen, the formation and the command and control centers. This enables superior situation awareness. Through the data fusion process, it has a network centric capability. It also has the Link 16 data link. It has ROVER (Remotely Operated Video Enhanced Receiver) which allows air crews and forward air controllers on the ground to share target images and videos. This will help the IAF in seamless coordination with its strategic partners in various missions.
Based on the processing power of the MDPU, the data fusion performs the number crunching on data provided by all the above sensors, IFF interrogator and various missile seekers. The data fusion yields a simplified and consolidated tactical picture. It shows correlated system tracks. The 3 steps of data fusion process are:
- Establishing consolidated track files and refining primary information provided by the sensors
- Overcoming individual sensor limitations related to wavelength / frequency, field of regard, angular and distance resolution, etc, by sharing track information received from all the sensors
- Assessing the confidence level of consolidated tracks, suppressing redundant track symbols and de-cluttering the displays
Human-machine interface and Cockpit
The HMI is based on the ‘HOTAS (Hands on throttle and stick)’ concept. It includes touch screens and a large tactical display. The wide (30 x 22) degrees holographic HUD shows flight parameters and tactical cues for immediate head-up work. The (20 x20) degrees head level display shows the big picture thereby enabling the pilot to think a step ahead in combat.
Apart from this, the mission planning will be tablet based and it will enable IAF mission planners to easily and quickly project scenarios on true maps. It also considers various dynamic constraints including load-out, fuel, area-denial etc.
The glass cockpit has a central computer that selects and prioritises information to display to pilots for simpler command and control. The seat is inclined rearwards at 29 degrees to improve g-force tolerance. The flight suit is intelligent and is controlled automatically by the aircraft to counteract in response to calculated g-forces. The cockpit has a DVI (Direct Voice System) which enables controls through various voice commands. However DVI will not be activated for final release of weapons from a safety point of view. The cockpit is fully compatible with NVGs. Rafales will feature the Mark 16F ‘zero-zero’ ejection seat and it has OBOGS. The Rafale’s flight computer is programmed to counteract pilot disorientation and employ automatic recovery in case of negative flight conditions.
The Flightsphere fight pilot tab system is a pocketed tab enabling full personal mission and flight planning system. It will be used offline to conduct mission planning and then carry it with them into the cockpit where it plugs right into the aircraft mission’s computer.
The Indian specific enhancement with this regard are the
- Helmet Mounted Display (HMD)
- Radio Altimeter height measurement from 10,000 feet to 15,000 feet
- Flight Data Recorder (FDR) recording time from 10 hours data to 16 hours data plus two hours of audio
- Training Mode in Missile Approach Warning System (MAWS)
The Golden Arrows and Falcons based out of Ambala and Hasimara air bases can liaison with the Battle Axes No.7 Squadron of Mirage-2000-5 from Gwalior. Those Mirages since upgraded, will allow the pilots from these 3 bases to conduct cooperative missions. Such missions can include aerial denial CAP operations on the chinese front. It can carry out precision strikes along LoC and even carry out deep penetration strikes. The use of such high end avionics and EW countermeasures provide the IAF covert capability. Hence Indian Rafales from the avionics and sensors perspective are a couple of steps ahead of its adversaries. And so the Indian Rafale is a 4.5 gen fighter from the avionics and EW perspective.
In the next part, we at Alpha Defense will cover the engine, the armament and maintenance aspects. And we will also look at the Indian Specific Enhancements done in those parts and how they provide the Indian Rafales with 4.5 gen capabilities.
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