Friday, July 31, 2020

J-20 vs Rafale


Introduction

Comparing the J-20 and the Rafale, to use a cliche, is like comparing oranges and apples. The two fighters were conceived and developed for completely different roles. However, the adversarial deployment of the two fighters in the context of the simmering India - China border dispute has fanned nationalist fervor and clamor for a comparison to such an extent that comparing oranges and apples seems perfectly logical.

Also, the Global Times, piqued by the claim of the former COAS that the Rafale is superior to the  J-20, has, without presenting a shred of evidence, fired a broadside trashing the Rafale as a generation behind the J-20 and claiming that the Rafale will "find it very difficult to confront a stealth-capable" J-20.

Well, it's time for fools to rush in where angels fear to tread. I may be a fool, but not a very verbose one, so I will confine this comparison to the BVR combat capability of the two fighters, because no one in their senses, not even the Global Times, will contend that the J-20 is superior to Rafale in WVR combat.

BVR combat capability is largely dependent on - the extent and capability of AWACS cover, RF signature, sensor suite, self defense suite, Man Machine Interface (MMI), and air-to-air missile range. For the comparison, we will assume a Rafale armed with Meteor and a J-20 armed with PL-15. Both feature dual pulse propulsion (A second stage ramjet in Meteor & a solid fuel rocket sustainer in PL-15) for thrusted end game maneuvering, max range of over 150-km, and an active seeker.

RF Signature


The J-20, which features full extent frontal aspect and limited extent side aspect LO shaping has a significantly lower radar signature than the Rafale which features limited extent frontal aspect LO shaping only. Both aircraft use RAM (Radar Absorption Material) and possibly some classified features to further reduce their RF signature. As far as RF signature goes, it's undoubtedly advantage J-20!

Sensor Suite


Both aircraft feature AESA radar, Optical Detection and Tracking system, and 360-deg FOV IR sensor based situational awareness.

AESA


The J-20 likely has a more powerful radar. Some estimates put the number of T/R modules on the J-20's AESA at 2000–2200. In comparison, the Rafale's RBE2 AESA features 1000 T/R modules. Assuming that the Chinese T/R modules match the efficiencies of the GaAs (Gallium Arsenide) T/R modules on the RBE2, and Chinese software algorithms driving the T/R modules on the J-20 AESA match the sophistication of the algorithms controlling the RBE2 T/R modules, the J-20 would have a much better max detection range and a more formidable EW capability. However, the two assumptions that we have made aren't trivial and are easily questionable by skeptics.

A better max detection range combined with the PL-15 air-to-air missile capable of leveraging the better range would give the J-20 a first to shoot advantage over the Rafale in BVR engagements.

However, the lack of sophistication of LPI (Low Probability of Intercept) features employed in the J-20's AESA radar could possibly negate the longer detection range  advantage. Once switched on, the higher radiating power of the J-20 AESA would be like a more powerful search light in a dark tunnel. It would see longer, but it would also be seen from longer. The Radar would be picked up by the RF sensors on the Raale completely negating the RF low observability of the J-20.

AESA radars leverage their control over individual T/R modules to scan and track while rapidly hopping frequencies over a wide spectrum making it difficult for RF sensors on adversary aircraft to track the radar. Hence the term LPI.  The question here is - how good is the LPI capability of the J-20 AESA? If it's not good enough against Rafale sensors, the longer range of the J-20 could well become a liability that is best avoided by keeping the radar switched off!

It's possible that the J-20 has the advantage with its AESA, however, we cannot be definite.

AWACS Cover


Data linked with and under control of an AWACS the J-20 would pose a formidable challenge to all IAF fighters including Rafale. With the AWACS providing situational awareness and target tracking information, there would be no need for the J-20 to switch on its powerful AESA radar and risk revealing its own position. It's conceivable, even likely, that the J-20 has the ability to relay tracking information obtained from the AWACS providing cover, to the PL-15 missile till it picks up the target on its own little AESA. 

Since J-20 has good RF stealth, IAF AWACS would not be able to obtain a weapon grade track on it to similarly advantage the Rafale. 

Under AWACS cover it would be advantage ++ for the J-20

Optical Detection & Tracking


The J-20 features EOTS-86 electro-optical targeting system and Electro-Optical Distributed Aperture System developed by Beijing A Star Science and Technology. The EOTS-89 reportedly resembles the EOTS of the Lockheed Martin F-35. It combines Forward Looking Infrared (FLIR) and Infrared Search and Track (IRST) capabilities.

The optical detection and tracking system on the Rafale, referred to as OSF-IT, facilitates passive long-distance detection and target identification before engagement. Located ahead of the cockpit on the dorsal section of the front fuselage, it comprises  two sensors -  the main IR detector that serves as FLIR with upto 100-km range on the left and TV/IR sensor/Laser ranger on right which  facilitates optical identification of targets upto 40 km away. Optical identification is considered imperative to rule out friendly fire fratricide.

One of the India Specific Enhancements (ISEs) sought by the IAF on the Rafale is an IRST, an indication perhaps that the existing OSF-IT is somehow constrained by the need for optical recognition and the IAF would prefer an IRST that allows pilots to passively engage targets, including stealth targets, at long ranges. Here it is pertinent to point out that the J-20 doesn't have IR stealth and as such would be prone to easy passive detection using IR, with detection range varying with weather and altitude.

With little or no reliable information available on the capabilities of the EOTS-89 on the J-20, it's moot which aircraft enjoys an advantage over the others.

In all probabilities Rafale has the advantage, but we cannot be definite.

Defensive Suite


It's possible to negate the first shot advantage of an adversary fighter through a very capable defensive suite. The SPECTRA integrated electronic warfare and defensive suit of the Rafale is one such very capable system. It provides  a multi-spectral threat warning capability against hostile radars with long-range detection, identification and accurate localisation of infrared, electromagnetic and laser threats.

The system incorporates radar warning, laser warning and missile warning receivers for threat detection plus a phased array radar jammer and a decoy dispenser for threat countering . It also includes a dedicated management unit for data fusion and reaction decision.

Perhaps the most potent feature of the SPECTRA is its deep integration with Rafale's systems. For example, the SPECTRA can jam or confuse enemy RF emitters using the RBE2 AESA.

The ability of the SPECTRA to automatically jam or seduce an active homing PL-15 would completely negate any advantage accruing to the J-20 from its stealth and more powerful AESA.

The Rafale has other very sophisticated features. For example, its concept of a defensive bubble. Once breached, the Rafale starts its "tandav"  dance that  may include firing its Mica all aspect missile backwards, releasing chaff and flares. Not surprisingly, there is a ISE for a towed decoy system.

 The J-20 can fire a PL-15 but it cannot ensure the missile will hit the Rafale!

Finally, a long shot missile can be evaded by energetic maneuvering, claims of a missile no escape zone notwithstanding. The IAF demonstrated this capability during Operation Swift Resort on February 27, 2019, when Su-30MKIs outmaneuvered PAF F-16 launched AIM-120D AMRAAM missiles. Indeed, the maneuverability and internal EW capability of a Rafale would make it as invulnerable to a missile with a radar seeker  as a Su-30MKI with Khibiny EW wingtip pods.

Rafale easily tops the defensive suite capabilities comparison.

Human Machine Interface (HMI)


Both Rafale and J-20 are single seat fighters with a lot of sensors - active and passive. How effectively a lone pilot can leverage the sensors would depend on the extent of sensor fusion and the effectiveness with which the threat situation is conveyed to the pilot through the HMI.

The J-20 features a glass cockpit, with one primary large color touchscreen LCD with three smaller auxiliary displays, and a wide-angle holographic head-up display (HUD).

The Rafale has a more sophisticated HMI. For short-term actions, it features a wide-field-of-view holographic HUD. For medium and long-term actions, analysis of the tactical situation as a whole (the “big picture”), the Rafale features a multi-image “Head-Level Display” (HLD). The HLD picture is focused at the same distance as the HUD picture to allow for fast eye transitions between head-up and head-down displays and the external world’s view.

In BVR combat, which works on the first to see, first to shoot paradigm, situational awareness is critical. The Rafale with its HLD probably does a better job of facilitating situational awareness.

Once the combat starts, the pilots rely on HUD and HOTAS (Hands on throttle and stick). As far as HMI goes, it's advantage Rafale.

Conclusion


The J-20's is undoubtedly the more stealthy of the two fighters.

Considering how little we know about the J-20's AESA and EOTS-86 Electro-optical Tracking System, it would be wrong to assume they are inferior to their analogs on the Rafale. However, since secrecy is usually employed to hide a weakness, not a strength, it's likely that the J-20 sensors are not at par as those on the Rafale. However, it is also likely that with the passage of time, J-20 sensors will improve.

Flying under AWACS cover, the J-20 would be a dangerous platform best avoided by the Rafale. The problem is, the J-20's front aspect stealth is good that it may not be possible for a Rafale to avoid butting heads with it. 

The Rafale almost certainly enjoys a significant advantage over the J-20 with its more advanced HMI and SPECTRA defensive suite.

Finally, Rafale's better maneuverability gives it a better chance of evading a BVR missile like the JL-15 that comes through its defensive bubble. The J-20's ability to outmaneuver a Meteor would be close to non-existent.

So, which is the better aircraft? Flying under AWACS cover, the answer could be categorical - J-20. 

What if the J-20 is not flying under AWACS cover? I would say, the one with the better pilot. 

What if the pilots are equally capable? I would say, the one with the  pilot who is better rested. 

What if the pilots were equally well rested? I would say - Rafale.

Monday, March 2, 2020

General Atomics Defender - A New Contour in Air Combat Evolution

GA-ASI Defender Concept

General Atomics ASI first tweeted the concept of its Defender drone (shown above) on February 28, 2020 saying that the drone would be capable of protecting USAF high value airborne assets (HVAA) in a contested environment.

Protecting its HVAA has become a high priority quest of the USAF with its adversaries - Russia and China - improving the range and end game maneuverability of their air-to-air missiles and acquiring targeting capabilities to effectively leverage the increased range.

The GA concept depicts a Defender concept drone launching a compact missile from its internal weapons bay. The drone is also armed with four AIM-120 Advanced Medium-Range Air-to-Air Missiles (AMRAAM) externally, two on each under-wing pylon. Another Defender is seen refueling via the boom on a KC-46A Pegasus tanker.

Aerodynamically, the Defender appears to have been designed for high endurance, aerial refueling, and cruise speed typical of HAVAAs that it will protect, such as tankers, AEW&C and strategic reconnaissance aircraft. The Defender could even serve as a loyal wingman defender for strategic bombers.

Interestingly, the Defender features a LO airframe with an internal weapon bay, yet it is shown carrying external stores! The apparent contradiction would suggest that the Defender could perform tasks other than protecting HVAAs.

Current HVAAs are not stealthy. When operating as loyal wingman for a HVAA, the Defender would trade some stealth for greater firepower by carrying BVR missiles externally. Doing so would not compromise its operational ability. At other times, the Defender could possibly operate independently in a strike role leveraging LO to take out targets deep in contested airspace.

It is likely that a Defender-like drone would be equipped with an AESA radar, electro optical sensors for 360-deg situation awareness and the ability to neutralize air-to-air missiles using DIRCM and seduction jammers. Its optimization for long endurance would seriously constrain the Defender's maneuvering ability, but then the Defender would not be engaging adversary fighters, it would be engaging BVR air-to-air missiles launched by adversary fighters, using its own air-to-air missiles!

One good reason why drones would better perform the task of protecting HVAA than manned fighters would human limitations associated with fighter operations. With a single set of crew, fighter endurance is limited to 7-8 hours at the maximum. HVAA, operating with multiple sets of crew have no such limitation. A unmanned drone would easily match, or exceed, the endurance of a HVAA.

Wednesday, November 20, 2019

There is room & time for Su-57 and AMCA in IAF Inventory


    Speaking on the sidelines of the Dubai Airshow 2019 in the UAE on November 18, 2019,  Sergey Chemezov, head of  Russia's Rostec, indicated that India and the UAE "have been considering and discussing buying the Su-57 "for a long time, though no decision has been delivered yet."

“The Russian side proposed to localize the production of individual components of the export version of the Su-57 in countries [that are interested,] we are talking about India, the United Arab Emirates, Turkey”

"Localization [has been offered] ... It does not matter whether it is [the] United Arab Emirates, India or Turkey, we will rely on what they can do"

Elaborating on his statement, Chemezov explained that the extent of the localization would be dictated by the industrial capability of the buyer nation. Russia would source local components if the buyer could manufacture them, but would not assist in setting up the supply chain. In the absence of an existing supply chain, localization would not be possible.

“If there are simply no such technological capabilities in the country, then it is simply impossible to do this,” S. Chemezov noted.


During his visit to Russia in July 2019, the former Chief of Air Staff (CAS) Air Chief Marshal Birender Singh Dhanoa had stated that the IAF will have a look at the Su-57 only after it joins active service with the Russian Air Force. Russian Aerospace Force has ordered 76 Su-57 jets, the first of which is scheduled to be delivered by the end of 2019.

During the annual press conference on October 5, 2019, ahead of the Air Force Day on October 8, 2019, the current CAS, Air Chief Marshal RKS Bhaduria said in response to a question from the press, “On the fifth generation (requirement), the AMCA has been given a go ahead and we have given it our whole support and are putting in our energies there. No import is planned in the foreseeable future.”

The remarks  were widely interpreted as ruling out import of any 5th gen fighter. However, they could also be interpreted as reiterating what the former CAS said - that at the appropriate time acquisition of the Su-57 could be considered.

It's likely that the IAF and the government are keeping their options open on the issue. Since Russia is unlikely to export the Su-57 before its own requirement of 76 aircraft is fulfilled there is no reason for India to commit at this stage.

AMCA Challenge

The AMCA is projected to enter operational service in 2035, if ADA and HAL stick to their timelines. Whether or not the IAF can fulfill its mandated role for the next 15 years without 5th gen fighter technology would depend on how threat perceptions play out. Here it's relevant to note that ADA / HAL have yet to demonstrate any of the critical technologies that would be required for the AMCA - LO shaping with super maneuverability, sensor fusion, super cruise, secure low probability of intercept high bandwidth data link and the ability to function as command center for other aircraft, including attack drones, when performing joint operations. As such, the ADA / HAL projected timeline looks overly optimistic.

IAF Options

Over the next 15 years, there are likely to be just two operational 5th generation fighters - Lockheed Martin's F-35 Lightening 2 and Su-57. The F-35 is unlikely to find favor with the IAF because Lockheed retains control over the stealth fighter's software even when selling it to the USAF. 

The choice before the IAF is to wait for the AMCA, or to acquire some Su-57s while it waits for the AMCA! There following are some factors that the IAF would well to keep in mind while exercising its choice.


Sergey Chemezov's statements at Dubai seem to suggest that Russia has drawn a clear line as to the extent and type of localization that it will agree to. If India were to purchase the Su-57, Russia would be willing to source any Su-57 component that India is in a position to manufacture and supply. It will not transfer technology to India to help make components locally as part of the deal!

Here it is relevant to point out that unlike the F-35, which relies primarily on its radar frequency low observability (RF LO) to safely operate in contested airspace, the Su-57 uses a combination of RF LO, electronic warfare (EW), supermaneuverability, and laser blinding of missile seekers to remain safe in contested airspace. As a result, the Su-57 features a powerful defensive suite laden with sensors, jammers and laser emitters that are not well known to the West. Under the circumstances, Russia's desire to limit localization is reasonable.

The Su-57 has generated a lot of interest in the middle east with Turkey and UAE openly negotiating and Saudi Arabia a future prospect. The reason for the interest is simple to understand - the US will not sell the F-35 to these countries because of the threat such sales would pose to Israel. Russia is keen to seize the opportunity and fill the gap not just to increase its arms sales but also to increase its clout in the Middle East. Under the circumstances, it wouldn't in India's long term strategic interests to play coy for too long.

Saturday, November 16, 2019

Raksha Mantri Rajnath Singh's Visit to UEC-Klimov in St. Petersburg Explained


Shri Rajnath Singh at the Klimov Plant

Introduction

During his recent visit to Russia from November 5 to November 7, 2019, India's Defense Minister, Rajnath Singh, visited Saint-Petersburg based UEC-Klimov (which is incorporated in United Engine Corporation of State Corporation Rostec).

Klimov is the largest developer and manufacturer of engines for Military and Civil aircraft in Russia.

During the visit the Indian Defense Minister was briefed on the product range of the enterprise and key stages of the production process and taken on a tour of the mechanical, assembly and test workshops.

Shri Rajnath Singh was shown the TV7-117ST, TV7-117V, VK-2500, and RD-33MK engines, all of which are of interest to India.

TV7-117ST Turboprop Engine

The TV7-117ST is turboprop engine which powers the Ilyushin IL-114 regional transport aircraft.


The Indian defense minister being briefed on the six-blade Aerosila AV-112 propeller fitted on the TV7-117ST engine.

In terms of efficiency and reliability, the TV7-117ST is among the best turboprop engines in the world in its class. The engine has a takeoff power rating of 3,100 hp and emergency power rating of 3,600 hp. On the IL-114, the TV7-117ST engine is coupled to  the newly developed six-blade Aerosila AV-112 propeller which increases thrust.

The TV7-117ST-01 engine is  variant of the TV7-117ST engine which powers the Ilyushin Il-114-300 regional liner. The TV7-117ST-01 is currently undergoing flight trials on an Ilyushin IL-76LL which was displayed at MAKS 2019

An IL-76LL fitted with a Klimov TV7-117ST-01 for flight trials


The IL-114-300 is a 52-64 seat analog of the ATR-42. India's state owned aircraft manufacturer, Hindustan Aeronautics Limited (HAL), is reportedly planning to make the IL-114-300 in India as a regional airliner for domestic airlines.

HAL has tied up with Ilyushin, initially to provide maintenance support for the IL-114-300 in India and later to assemble the plane in the country.

In September 2019, HAL chairman R Madhavan was quoted in the report as saying,
“Ilyushin is working on civil certification of this aircraft, that is likely to come by 2021. After that they get European (aviation regulator) certification also for using this aircraft in civilian space. We signed a non-disclosure agreement with Ilyushin for doing maintenance of this aircraft in India for its customers from India and nearby countries.”

Configured as a military transport, the IL-114-300 could also replace the 100 odd Antonov An-32 aircraft of the IAF. There is also a maritime variant, IL-114MP, which too could be of interest to India.

TV7-117V Turboshaft Engine

The TV7-117V turboshaft engine is a helicopter powerplant version of the TV-117SM engine. Two TV7-117V turboshaft engines, each of 1753 kW power rating are fitted on Russia's newest transport helicopter Mi-38. The Mi-38 was unveiled at MAKS-2019 and made its international debut at the Dubai Airshow 2019. It's a transport helicopter designed and built with focus on passenger safety and comfort, environmental friendliness, and low noise on the ground..

Russia is pitching the Mi-38 to Pawan Hans Limited, India's state owned civil helicopter company, as a replacement for existing Mi-172.

The Mi-38 can be operated in a wide range of climatic conditions, including marine, tropical and cold climates. The high altitude performance of the helicopter is an important USP. The Mi-38 set a world record reaching an altitude of 8,600 meters, which is almost as high as Mt. Everest [8,848 meters].

VK-2500 Turboshaft Engine

The VK-2500 (2,700 hp) turboshaft engine is a modern high-hot variant of the Klimov’s TV3-117 (2,100 hp) which powers the Mi-8/Mi-17 helicopter family of helicopters.

Klimov VK-2500PS engine on display at MAKS 2019


The Indian Air Force (IAF) currently has around 151 Mi-17V-5 helicopters powered by the TV3-117 engine, the last of which were delivered in January 2016. Russia is proposing that the IAF upgrade its Mi-17V-5 fleet to the Mi-171A2 standard powered by VK-2500PC engines. Besides more powerful and efficient engines, the Mi-171A2 features upgraded main rotor, gear systems and fuselage and advanced avionics. The total number of improvements exceed 80.

The latest variant of the engine, VK-2500PS, offers extended service life and full authority digital engine control system for improved performance.

RD-33MK Turbofan Engine

The RD-33MK engine, is a fourth generation engine derived from the RD-33 Series. If differs from the baseline model in having a new low-pressure compressor, an improved high-pressure compressor, an improved cooling turbine, an advanced smokeless combustor and up-to-date AVARK-42 FADEC system.

The RD-33MK engine has higher thrust, higher reliability and a longer service life of up to 4,000 hours.

The RD-33MK was developed to power the MiG-29K/KUB and MiG-35.

The RD-33MK variant which powers MiG-29K/KUB additionally features emergency takeoff rating and corrosion resistant coating on the gas air flow duct. The emergency takeoff rating makes it possible for the aircraft to takeoff from the aircraft carrier deck without use of catapult launcher.

The Indian Navy procured 45 MiG-29K/KUB for carrier borne operations from INS Vikramaditya, its lone aircraft carrier. Russia has now pitched the RD-33MK powered MiG-35 against the IAF's requirement for 110 medium class fighters.

During the meeting with the top management of the enterprise Shri Rajnath Singh put a high value on the scientific-design capacities of JSC “UEC-Klimov”, the quality and the scale of the up-to-date production complex.


Sunday, January 20, 2019

Rafale - Nature of the India Specific Enhancements (ISEs)

Rafale at Aero India 2017

The Rafale contract envisages 13 India Specific enhancements (ISEs) valued at Euro 1.3 b. There is no official list of the ISEs in the public domain, however, based on media reports the ISEs include:

  1. More powerful engine
  2. Radar enhancements
  3. Helmet mounted display
  4. Towed decoy system
  5. Radar warning receiver
  6. Low band jammer
  7. SATCOM
  8. Radio altimeter (CFIT avoidance?)
  9. Ability to start and operate from High Altitude Airfields
  10. 10-hr flight data recorder
  11. Infrared Search and Tracking (IRST)
  12. Missile Approach Warning System (MAWS)
The ToI reported on January 20, 2019 that the 13 India-specific enhancements or upgrades on the 36 jets would become fully operational only by September-October 2022 as they will require another six months to undergo "software certification" after all the fighters have arrived in India. In the past, there were reports that the ISEs would be carried out in India for all but the first Rafale to be delivered. The ToI in its above report states 

The first Rafale jet with the 13 ISEs is currently undergoing flight-testing in France, which is expected to achieve certification by April 2022. By this time, the other 35 fighters with the requisite hardware upgrades will be delivered to India in batches of 4-6 each. "Thereafter, it will take another six months to finish the certification for the software to drive the ISEs for all the 36 jets," said another source.

The above quoted and other past reports suggest that the ISEs are largely software related. 

The nature of the ISEs also reinforces the likelihood of they being primarily software related. If indeed that is the case, it would suggest that Dassault would be supplying India the source code of the sensors and display systems as part of the ISEs. Using the source code and ISE implementation documentation supplied by Dassault, IAF personnel would be able to customize the existing algorithms used and hone them to address the specific threats that the IAF faces. 

The IAF would also be able to customize and if required tweak the display layout and symbology associated with multi-function and head up displays. That would explain why the IAF cannot detail the ISE specifics despite questions being raised about the high price being paid for them. 

The following is an illustrative example. One of the ISE is LBJ (Low Band Jammer). However, LBJ is part of the Spectra EW suite that equips the F3R variant that India is purchasing from Dassault, so why is it listed as an ISE? Well.., because through customization the algorithms used to jam low band RF can be tweaked to handle the specific threats faced by India. The nature (frequency band, pulse characteristics, etc.) of RF emissions of Indian adversaries would be well known to India but not France. So software customization would be best handled by IAF personnel. 

Similar would be the case for the AESA radar, towed jammer, IRST, MAWS, CIFT avoidance, SATCOM, etc.

The IAF would also want to customize the layout and symbology used on the fusion displays for standardization across platforms. It is unlikely that the IAF would have bought a software intensive platform such as the Rafale without the ToT for deep customization. The ToT would additionally allow the IAF to use Indian developed weapon systems like the Astra BVR missile and in the future weapon systems such as the NGARM.

There is another facet to the need for ISEs, Rafale would be operated by at least two other countries friendly to one of our adversaries leaving a window  ajar for leaks of critical algorithms used in the Rafale. (The other adversary is an IPR thief of repute and would steal from any country - friendly or not!)

This post is based on this twitter thread posted on January 19, 2019.

Is Russia Adding Formidable 6th Gen Capability to its Su-57 fighter?

via Twitter
Recently, the T-50-3 was observed in new pixelated camouflage pattern with an insignia on the tail depicting a Okhotnik UCAV radio linked to a T-50. (See above)

The T-50-3 featured three new protrusions on the fuselage - A under fuselage sensor slightly ahead of the cockpit, an over the fuselage antenna just behind the cockpit, and an antenna on the underside of the tail boom in between the exhaust nozzles.

The insignia and the protrusions have fueled social media speculation that the aircraft has been upgraded to control and guide LO drones capable of penetrating contested airspace to attack targets or relay targeting data

The ability to control stealthy drones for penetrating heavily contested airspace, or legacy aircraft operating as loyal wing-man weapon trucks is a sixth generation fighter features. For example, the Franco - German - Spanish FCAS, which is planned to enter operational service in 2040, will feature this ability.

Okhotnik (Hunter) UCAV

A see through model of the Sukhoi Okhotnik (Hunter) UCAV was first unveiled by KRET at MAKS-2015. The UAV model closely resembled Northrop’s carrier-based X-47B demonstrator, but added two lift fans on each wing and vertical stabilizers.

See through Okhotnik model at MAKS 2015 [via Twitter]


The heavy (20t)  UAV, reportedly capable of flying at 1000 kph, performed its first T/O run trial at the Novosibirsk Aircraft Production Plant in November 2018 reaching a speed of 200 kph.

Compensating for the Su-57's Lack of All Aspect Stealth

The Su-57 features good front aspect stealth, but not so good side and rear aspect stealth making it a capable head on interceptor, but not such a capable offensive platform. Ground based radars and AWACS would pick up a Su-57 much more easily than they would a F-22 Raptor which features good all aspect stealth.

Good front aspect stealth in combination with L-band leading edge AESA radar and good front sector optronics make the Su-57 a formidable interceptor of LO observable attack aircraft such as the F-22 Raptor, F-35 Lightening 2, and the J-20. In order to keep the aircraft affordable, an economically stretched Russia initially concentrated on the defensive capabilities of the Su-57.

Sukkhoi Okhotnik UCAV (via Twitter)

The ability to guide a LO sensor / attack platform into contested adversary airspace to obtain targeting data would now give the Su-57 formidable attack capability. It would also explain why Russia has invested heavily in developing long range stealthy cruise missiles such as the Kh-59MK2  for internal carriage on the T-50.

The limited weapon load of the very stealthy F-22 Raptor is its greatest shortcoming. By opting for differently-abled stealth platforms specialized for different roles with the ability to work as a single system, Russia may be poised to once again score with its asymmetric approach to countering American economic and technical prowess. 

Tuesday, October 24, 2017

Building a Case for the F-35 by Trashing the Su-57?


Twitter image posted by @BuddyPixy

A recent report in the ToI titled 'Fifth Generation Fighter deal. Can India cancel it?' suggests that the IAF has serious reservations about going ahead with the FGFA deal.

The report quotes unnamed serving IAF officers as saying that the RCS of the Su-57, on which the FGFA would be based, does not have an RCS comparable with the F-35, the Su-57 engine is not modular, and the cost of operating Russian aircraft is exorbitant.

(Note: Serving IAF officers are not authorized to speak to the press, which justifies the anonymity of the sources quoted by the report. However, anonymity also raises the possibility of fabrication.)

All the three points raised by the anonymous IAF sources are dubious.

RCS Comparison

The RCS comparison in the report is simplistic. RCS varies with the aspect of the aircraft (front, side, rear) and the frequency of the RF energy used by adversary radar. According to open source, western figures Su-57 RCS varies from 1.0 sqm to 0.5 sqm while the RCS for the F-35 is very impressively in the range of 0.0001 sqm to 0.0015 sqm! (The report wrongly quotes the F-35 RCS as being 0.2m.)

What the report does not mention is that the Su-57 features  2 L-band radars in the leading edge root extension (LEX) of its wings.

L-Band radars are more effective against Low Observable (LO) targets than X-Band radars typically fitted on fighters including the F-35. However, because of their longer wavelengths. L-Band radars feature reduced resolution. The combination of L-Band and X-Band, supported by good algorithms to fuse the target returns, can significantly reduce the effectiveness of LO shaping. In other words, the Su-57 could conceivably detect an F-35 as easily as an F-35 can detect a Su-57, their vastly differing RCS notwithstanding.

In clear weather, the effectiveness of the X and L band radar combine would be further increased by the fusing of Su-57 IRST readouts. (Russian IRSTs are known to be very capable.)

Survivability in Contested Airspace

Another important factor to keep in mind is that LO shaping is a means not a goal. The goal is survivability in contested airspace. Air Forces want a fighter that can operate in heavily defended adversary airspace without being easily shot down.

Contested airspace survivability comes from a combination of LO, Electronic Warfare (EW), and Self Protection Suit.

LO shaping makes it difficult for airborne and ground radars to continuously 'see' the adversary, EW spoofs (generates false returns) and blinds airborne and ground radars making it difficult for them to guide surface-to-air missiles, and a Self Protection Suit blinds or confuses the IR or RF seekers fitted on air-to-air and surface-to-air missile

Russian EW capabilities are good. The Su-57 will extensively use them to spoof adversary radar.

Boeing F/A-18E/F

As part of the service life extension program for the F/A-18E/F, Boeing is introducing modifications that will make the aircraft more stealthy. 

Boeing F/A-18 and EA-18 program manager Dan Gillian says the aim of the F/A-18E/F modifications is to make the aircraft "stealthy enough in a balanced survivable way to be effective." 

“The F-35 is a stealthier airplane, but we have a balanced approach to survivability, including electronic warfare and self-protection."

Like the proposed F/A-18E/F, the Su-57 takes a more balanced approach to survivability.

FGFA Engine

The Su-57 currently features the AL-41F1 engine, The production variant of the aircraft would be fitted with the Product 30 engine which is 30% lighter, features improved thrust (19,000 kgf vs. 15,000 kgf), has better fuel efficiency and fewer moving parts resulting in improved reliability and 30% lower life-cycle cost.

The extent of modularity of the Product 30 engine is not known. However, like LO, modularity is a means not a goal. The engine has less moving parts and is hence more reliable. 

The Product 30 engine is still on the test bench. Any comments on the extent of its modularity would be highly speculative.

Operating Costs

Russia chose to make the Su-57 less stealthy than its western analogs because it wanted to reduce operating costs! Any suggestion that operating costs of the Su-57 would be higher than those of the F-35 would not just stretch the truth, but also the imagination!

Conclusion


What I have stated above was part of my response to a request for comments on the ToI report from an online publication. The publication quoted just my comments on the FGFA engine (after introducing a grammatical error.) The comment was picked up by other news outlets including The Drive. Indeed, The Drive Warzone goes on to build a case for the IAF to drop the FGFA and opt for the F-35 instead! Which makes me wonder? Was that the original intent of the ToI article? 

I believe that having appointed an expert committee led by  Air Marshal S Varthaman (Retd.) the government should accept its recommendations.

I also believe that neither Russia nor the US is going to part with its frontline stealth technology and any F-35 purchase is going to come with more strings than the babus in MoD or the Air Marshals in Vayu Bhavan could count in the days preceding their retirement.