|Last Updated: Fri Mar 29 10:48:39 UTC 2013|
| Surviving the Modern
Integrated Air Defence System
The only US combat aircraft design to be in production before 2020 with the capability to penetrate and survive in modern Integrated Air Defence Systems is the F-22 Raptor. The depicted aircraft is dropping a GBU-32 JDAM guided bomb (US Air Force image).
Defense Policy Agenda Statement,
No classified materials needed to be used, nor were classified
materials used in the preparation
of this analysis.
The stunning successes achieved in US led air campaigns since 1991 have been owed more than anything to the US technological and operational capabilities to penetrate and suppress opposing Integrated Air Defence Systems (IADS).
Ongoing technological evolution of IADS capabilities since 1991, and a failure by the US to further evolve its once formidable relative capabilities, now present the prospect of the US being unable to achieve a decisive advantage in an air campaign, either quickly or with low expenditures in aircraft and aircrew losses.
At this point in time the US has firm commitments for only 183 F-22A Raptor aircraft, and an operational fleet of only 20 B-2A Spirit stealth bombers. Yet these are the only aircraft capable of surviving in the kind of IADS environment we now see emerging globally.To best appreciate exactly how and why this strategic change has occurred, and occurred so pervasively, it is necessary to explore defence penetration strategies, Russian and Chinese technological strategy in IADS evolution, and how these strategies are manifested in specific designs for IADS components.
The subject of technological strategies and countering technological adaptations for penetrating IADS has been recently detailed in , , ,  and . However, to date we have yet to see a more comprehensive analysis of the ongoing trends in this evolution.
Until the advent of the F-117A during the mid 1980s, tasked in a large part with crippling key command posts in an opposing IADS, Western defence penetration and IADS suppression strategies were essentially a sophisticated but linear evolution of techniques first pioneered during the 1940s Combined Bomber Offensive over Germany.
During that period the RAF and USAAF first employed standoff jamming and escort jamming aircraft, but also employed low altitude penetration below radar coverage on numerous critical bombing raids. The British pioneered the model of Suppression/Destruction of Enemy Air Defences (SEAD/DEAD) flying rocket and gun armed Typhoon fighters against Luftwaffe search and acquisition radars. It is also significant that the Germans pioneered the Surface to Air Missile (SAM) with their Wasserfall ands Rheintochter designs, neither of which achieved operational status, but both of which provided the technological jumpstart for US, British and Soviet developments post-war , .
The protracted Vietnam conflict provided the next important stage in this evolution, as the Soviets deployed the S-75/SA-2 Guideline SAM en masse to defend North Vietnam, and the US developed and deployed specialised EB-66, EA-6A/B and EKA-3B tactical jamming and anti-radiation missile firing EF-100F, A-6B, F-105G and EF-4C SEAD aircraft to cripple this IADS. In parallel the US deployed the F-111A which used automatic terrain following to evade SAM acquisition and engagement radars , , , .
While opinions and assessments often differ widely on the success of the US SEAD/DEAD campaign in Vietnam, what is abundantly clear is that the combination of jamming and lethal attacks against missile batteries and supporting radars worked, to the extent that sustainable loss rates in penetrating bombers were achieved. In this respect the combination of jamming and lethal attacks must be considered to be the winner, as the IADS strategic aim of achieving unsustainable bomber loss rates was simply not achieved. Against the tens of thousands of sorties flown, the success rate of the SAMs was not good enough to deter penetration.
The 1973 Yom Kippur conflict presented a mixed outcome. Initially the highly mobile Soviet supplied 2K12 ZRK Kub / SA-6 Gainful and static S-125 Neva / SA-3 Goa inflicted significant loss rates on Israeli fighter aircraft, but innovative low level flying tactics and use of land manoeuvre forces swung the final outcome in favour of the Israelis , .
The US further refined its technological capabilities during the late 1970s, developing the very capable F-4G Wild Weasel IV and EF-111A Raven, both of which set long term benchmarks for these respective capabilities. The rather simple AGM-45 Shrike anti-radiation missile was replaced by the sophisticated digital AGM-88 HARM .
The Soviet reaction to the IADS debacle in Vietnam, and the not entirely convincing performance during the Yom Kippur conflict, and the subsequent Syrian debacle in 1982, was to develop a new generation of SAMs and radars, with more range, better jam resistance, and importantly much better mobility .
These weapons were the S-300P / SA-10A Grumble semi-mobile strategic air defence missile, with its semi-mobile 5N63 Flap Lid engagement radar, modelled on the US MPQ-53 Patriot radar, and the sibling Soviet Army high mobility weapon, the S-300V / SA-12A/B Giant/Gladiator , .
By the early 1980s Soviet Voyska PVO units were receiving the self propelled S-300PS / SA-10B, soon followed by the digital S-300PM / SA-10C, a true analogue to the MIM-104 Patriot, but with better battery mobility. Concurrently, the medium range Army 2K12 / SA-6 was being replaced with the more capable 9M38 / SA-11 Gadfly .
The distinguishing features of this late Cold War generation of IADS systems were in very high mobility, all three of these systems being capable of firing five minutes after coming to a halt, and being capable of departing a location within 5 minutes of completing a missile engagement. The S-300PS/PM and S-300V both employed high power, and for that period, exceptionally long ranging phased array engagement radars, much more difficult to jam than the engagement radars in the SA-2, SA-3 and SA-6 deployed and used during the 1960s and 1970s, and much more difficult to target with anti-radiation missiles. Importantly, the SA-10, SA-11 and SA-12 employed radio frequency datalinks, which allowed the battery command posts, engagement radars and missile launch vehicles considerable flexibility in how the battery was deployed geographically , .
When Saddam invaded Kuwait, the US possessed a robust conventional SEAD/DEAD capability in its fleets of HARM firing F-4G Wild Weasel and F/A-18 Hornet fighters, and a robust tactical jamming capability in the mixed fleet of EF-111A Ravens and EA-6B Prowlers. Less visible was the 37th Tactical Fighter Wing equipped with 60 F-117A Nighthawk stealth fighters.
The overwhelming and indeed crushing defeat of Saddam’s Soviet and French supplied IADS in 1991 was the result of a concentrated, coordinated and sustained effort using aerial decoys, SEAD/DEAD assets, jammers against IADS radars, and the F-117A against key hardened command posts , .
There are several key observations, which must be made about this campaign.
The first is that it was representative of the NATO vs. Warpac scenarios of that period – while the Soviets had good numbers of SA-10, SA-11 and some SA-12 deployed, these were mostly committed to protecting strategic targets inside Soviet territory, leaving much of the IADS capability in Central Europe to Warsaw Pact allies equipped with a mix of SA-2, SA-3, SA-4, SA-5 and SA-6 batteries. While these systems were better maintained, often of better subtypes, and more competently operated than Iraqi systems, they also had to cope with the full capabilities of NATO and the US, not just the forces deployed during Desert Shield.
The second observation is a corollary of the first, in that the new highly mobile SA-10, SA-11 and SA-12 were not deployed in Iraq. Indeed, Iraqi deployment doctrine of that period paid little attention to mobility, with SAM batteries nearly always fixed in location.
To achieve the intended effect against this legacy IADS, the US expended hundreds of drones, and importantly, around 2,000 AGM-88 HARM anti-radiation missiles, to which must be added the complete but smaller warstock of British ALARM anti-radiation missiles.
The Desert Storm campaign remains a key historical benchmark, but unfortunately it has also created quite unrealistic expectations of what can be achieved over the longer term.
The next significant air campaign was the 1999 Operation Allied Force effort against Serbia. While it has been considered a success due to the low aggregate loss rates of Coalition aircraft, the success of the SEAD/DEAD effort was much less convincing. While the Coalition did successfully destroy most of the static SA-2 and SA-3 batteries, they only managed to destroy 3 out of 25 mobile SA-6 batteries, or 12% percent of that total, despite the large number of HARMs launched. Disciplined “shoot and scoot” tactics by the Serbian defenders, intended to keep missile batteries alive, resulted in a persistent threat of sniping attacks which kept much of the NATO force of F-16CJs, EA-6Bs and Tornado ECRs occupied chasing SAM systems, largely to no avail. The Serbians did execute one particularly successful ambush, killing an F-117A stealth fighter using a legacy SA-3 missile battery .
The Allied force campaign happened a decade ago, since then there have been no significant air campaigns in which an IADS was employed to deny access to attacking aircraft.
What the Desert Storm and Allied Force campaigns did achieve was to provide both a focus and an imperative for further evolutionary growth in IADS capabilities, doctrine and technological strategy.
In the decade that has elapsed since Allied Force, we have seen a commercially and strategically driven flurry of developmental activity in the Russian and Chinese defence industries, reacting to the lessons of the 1990s, but also exploiting the globalised market for high technology, especially computer technology, commodified high performance microprocessor chips, and Gallium Arsenide microwave chips. Perhaps the only silver lining in this situation is that the global Internet provides Western observers with a much clearer picture of technological evolution in Russia, less so in China, than during the late Cold War and early 1990s .
We can now identify a number of key trends in IADS evolution, which are well established, and will define the basic features of well constructed near future air defences, such technology being globally marketed by Russia, former Soviet Republics, and China.
All Russian SAM systems designed over the last decade can “shoot and scoot” in 5 minutes, with all key components self propelled, now mostly on all terrain wheeled vehicles with high road mobility. The most recently developed SAM system acquisition radars can redeploy inside 15 minutes. Chinese developed radars and SAM systems are following a similar pattern, with an increasing change to self-propelled designs [i].
A concurrent trend has been to market self-propelled mobility upgrades for legacy SA-2 and SA-3 systems, leaving only the legacy SA-5 as an inherently static system .
Most recent Russian engagement and acquisition radars are automatic pseudorandom frequency hoppers, many in fact “fast” frequency hoppers with pulse-to-pulse hopping capability. A similar trend is now being observed in Chinese radar designs. Such radars will exhibit similar jam resistance to Western frequency hopping technology used in radar and digital networks.
An increasing proportion of Russian engagement and now also acquisition radars are phased arrays, with at least two designs being active arrays with solid state transmitter modules (AESA). These provide agile beam steering, adaptive jammer nulling, adaptive allocation of transmit power, in addition to very low sidelobe emissions to frustrate emitter locating systems and anti-radiation missile seekers. All of the three recent Chinese engagement radars disclosed are phased arrays , , .
An important advantage in all phased arrays is they permit angle jam resistant high precision angle tracking by fast sequential lobbing, emulating monopulse techniques. They also permit high update rate angle and range tracking of multiple targets. This not only increases the potency of SAM engagement radars, but also blurs traditional distinctions between engagement radars and acquisition radars. If an outbound SAM is receiving midcourse trajectory updates produced by a VHF-band phased array “acquisition” radar networked with the SAM’s X-band “engagement” radar, both might as well be considered to be battery “engagement” radars.
The inevitable long-term trend is that Russian designers will move to active arrays (AESA) once manufacturing obstacles are overcome, resulting in further improved peak power performance.
The trend in Russian missiles has been unequivocally toward increasing range, and concurrent increases in radar power-aperture product as a result. The improvements in missile range are partly due to more energetic solid propellants, but also due to “smart” trajectory control laws in the digital guidance systems employed. The longest ranging Russian SAMs, the 48N6E2/E3 and 40N6E, all fly ballistic trajectories against distant targets, achieving respectively ranges of 250 km and 400 km. Smart trajectory control in at least one digital upgrade to the SA-3 doubled its kinematic range , .
The increases in radar peak power required to support the increases in kinematic range provide useful counter-stealth capabilities, effectively neutralising stealth designs in the -20 dBSM performance class , [ii].
The late Cold War preference for compact antennas and S-band operation has been supplanted by a preference for designs operating in the L-band and VHF-band. Of the six recent Russian acquisition radar designs, only one may operate in the S-band, the remainder being beyond any question L-band or VHF-band designs.
The preference for lower bands is intended to defeat stealth shaping and coatings optimised for S-band and X-band threats, but also electronic warfare self protection systems most of which cannot jam below the S-band due to antenna size limitations , [iii].
The globalised market for computing hardware and open source software has seen all recent Russian radar and missile system designs built around COTS computing hardware and more that often open source software, especially the Linux operating system, and C/C++ programming language. This trend encompasses signal processing, track data processing, display graphical interface processing, networking, and command post processing , .
The availability of advanced yet commodity high performance computer hardware suitable for embedded applications has removed one of the single greatest technological advantages held by the Western world over the Soviets throughout the Cold War period.
The availability of COTS digital hardware and open source software has been a fundamental enabler for the introduction of a range of advanced processing algorithms and techniques until recently exclusive to Western radar designs.
Non Cooperative Target Recognition (NCTR) techniques based on target return fine structure are now appearing in Russian radar designs .
Space Time Adaptive Processing (STAP) techniques, which adaptively reject surface clutter and chaff, are also now appearing in Russian radar designs .
Track fusion algorithms, which are the basis of the US Navy Cooperative Engagement Capability (CEC) system, are now available in at least one Russian design, the Salyut Poima E .
Radio frequency emitting decoys intended to seduce anti-radiation missiles are now being offered for most Russian radars, many of which include integration features to synchronise radar emissions with multiple decoys .
Inflatable visual decoys are on offer for some Russian equipment items, including the S-300PMU/S-400 series TELs.
At least one Russian radar is being offered with a comprehensive countermeasures suite, including a smoke generator to defeat laser and television guided smart weapons, a flare dispenser to defeat infrared and imaging infrared guided smart weapons, and a chaff dispenser intended to defeat millimetre wave (MMWI) band radar seeker guided weapons .
Russian GPS jamming equipment has been available for at least a decade in the global market.
A trend which emerged during the nineties and has been reinforced by recent design optimisations in the Tor M2E / SA-15 and Pantsir S / SA-22 SAM systems, is the use of these short range point defence missile or missile / gun systems to shoot down smart munitions targeting SAM battery acquisition and engagement radars. The cited intent is to kill anti-radiation missiles, cruise missiles, or any other guided munitions being used by SEAD/DEAD aircraft against the missile battery , .
This is more than marketing, in that both the SA-15 and SA-22 have been re-equipped with agile beam phased array engagement radars designed to concurrently track many targets and engage same with missiles.
Cold War era Soviet medium and long range SAMs employed primarily command link guidance and semi-active radar homing guidance, later supplemented by Track Via Missile guidance similar to that in the US MIM-104 Patriot. SAM designers did not espouse the philosophy of AAM designers, who would equip like missile airframes with alternative radar, infrared, and most recently, X-band anti-radiation homing seekers.
Since the end of the Cold War we have seen Serbia and Iraq experiment with the retrofit of infrared homing seekers to legacy Soviet SAM types. Agat in Russia have developed derivatives of their active radar AAM seekers for use in the SA-6/8/11/17 SAM rounds. China developed an anti-radiation seeker for use in their FT-2000 SAM, claimed to be a variant of the HQ-9.
The expectation that SAM rounds will be equipped only with a single seeker type belies the pressures to provide diversity in seeker types to overcome defensive jamming.
The Soviets were heavy users of digital datalinks and this propensity has expanded in more recent designs for SAM systems and supporting IADS elements, as commodified Gallium Arsenide chips have reduced the cost of development and production, and widely available software design tools have accelerated the development tempo.
Many contemporary equipment designs are designed around networks to provide wireless connectivity between self propelled components, and COTS networking to provide connectivity inside equipment.
Unlike the Western preoccupation with providing generalised “Metcalf-like” connectivity, Russian designers have been more disciplined and tend to use wireless connectivity for more specific functions.
Low Probability of Intercept (LPI) techniques involve the use of exceptional frequency agility, noise-like waveforms, and controlled emission patterns, to make the interception of radar or datalink transmissions exceptionally difficult.
To date there have been no significant open source disclosures on the use of these techniques in Russian datalinks or radars.
However, most if not all of the prerequisite technologies needed to implement LPI have been mastered by Russian industry. The assumption that LPI will not be introduced and employed in IADS components is simply not supportable even in the near term [iv].
A feature long expected and recently announced as part of the S-400/SA-21 SAM system is the provision of interfaces to permit the battery to accept targeting track data from 85V6 and 1L222 series mobile passive emitter locating systems , , .
Such emitter locating systems have proven very effective at three-dimensional tracking of aircraft, using their JTIDS/Link-16 network terminal, IFF, or TACAN emissions. Emitting ISR platforms are especially vulnerable to tracking by such systems.
If used in concert with a SAM system engagement radar, where the radar will “tease” emissions from defensive jammers in an aircraft to facilitate tracking, the emitter locating system may effectively nullify the benefit of having a jammer.
Most recent Russian radar designs include capabilities for angle tracking of opposing jammers.
Hybridisation of SAM systems, where legacy missiles and launchers are supported by newer technology engagement radars, has a well established history in the Soviet IADS environment, but mostly in the provision of “backward compatibility” in evolving families of weapons. The two best examples are the SA-6 and SA-11 family of weapons, where transitional subtypes could control Fire Dome engagement radars on TELARs, and the SA-10/20 family of weapons, where later 30N6 Tomb Stone radars can guide SA-10 5V55 series missile rounds.
A more recent trend has been the hybridisation of dissimilar systems, where a modern agile beam phased array engagement radar gains the capability to guide legacy missiles associated with an entirely different SAM system design. The best example is the SA-20/21 family of systems acquiring the ability to control the SA-5 Square Pair illuminator radar, and emerging evidence of likely Chinese integration of the legacy SA-2/HQ-2 missiles with the new H-200 phased array engagement radar developed for the new HQ-12/KS-1A SAM .
Hybridisation is especially concerning for two reasons. The first is that it completely obsoletes all extant electronic warfare techniques and equipment developed against the legacy radar – and it may be difficult to determine its presence a priori. The second is that a new phased array radar will expand the lethality of the system providing many capabilities absent in the legacy radar.
What is abundantly clear at the close of the first decade of the 21st century is that almost two decades after the fall of the Soviet regime, the former Soviet defence industry has remade itself and successfully assimilated much of the digital and microwave technology base available in the global market.
With the exception of a handful of technologies, such as advanced low observables, high density chip design, and X-band active phased array (AESA) modules, Russian industry has closed the gap in most key areas of IADS related technology.
This should be neither surprising nor unexpected, but given repeated statements, and related policy decisions, by numerous senior Western DoD bureaucrats in recent times, it is evident that this “new reality” is either not understood, or there is complete indifference to its existence.
the specific impacts
evolving IADS technologies and doctrine, it is well worth testing the
Western tools used to defeat IADS, against the new reality.
The US and its Allies have relied in recent decades upon a small number of pivotal technologies and techniques to defeat IADS and gain access to hostile airspace.
These include precision emitter locating systems, the anti-radiation missile, guided bombs and cruise missiles, Electronic Warfare Self Protection equipment carried by penetrating aircraft, high power support jamming aircraft, and most importantly, stealth. To a greater or lesser extent, all of these technologies are now being challenged.
Modern Russian doctrine is to directly attack airborne ISR assets using very long range SAMs and AAMs .
Where the ISR system is not so threatened, it will have to contend with low sidelobe antennas and smart/agile scan patterns, the by-product of a move to phased array designs. Further challenges will arise from a well proven doctrine of carefully controlling emissions, using passive sensors, and the exploitation of the high mobility of modern IADS components .
The conclusion is that future IADS elements will be much more difficult to locate and track. Penetrating ISR assets with high stealth performance will be required.
The defeat of Anti-Radiation Missiles (ARM) has absorbed considerable intellectual effort in Russia, which is now yielding dividends.
An ARM will have to overcome synchronised, smart emitting decoys, which are likely to employ extant Russian DRFM (Digital RF Memory) technology and thus be extremely difficult to distinguish from the target emitter. In addition, emitters will generate low side and backlobes and may exploit agile electronic beam steering to evade interception. The pervasive use of self-propelled radars will exacerbate the problems observed in the OAF campaign of 1999.
If the ARM can overcome these impediments, it has to survive interception by short range weapons tasked with interception of the ARM.
Unless the ARM is hypersonic, or exceptionally stealthy, or both, it is likely to fall victim to the terminal defences deployed in the IADS.
While recent developments such as ramjet propulsion to improve kinematics, and multimode seekers to attack non-emitting targets, will improve anti-radiation missile effectiveness against high mobility threats, they cannot address the active use of countermeasures against the missile seeker, and the use of defensive fire against the missile itself.
Guided bombs have been used increasingly for the DEAD role. Like ARMs, they will have to contend with countermeasures and decoys, and jamming of the GPS carrier signals. They will also have to survive terminal short-range missile and gun defences.
A consideration for glide weapons like the JSOW, winged JDAM and SDB, as well as cruise missiles, is that self-propelled IADS components may no longer be at the DMPI when the weapon arrives.
Time of flight is therefore an issue in its own right and for standoff attacks with cruise missiles such as the Tomahawk, CALCM and JASSM, the basic operating cycle of a mobile battery may be enough to defeat the weapon. While datalinks offer potential for retargeting a cruise missile in flight, they increase the vulnerability of the weapon, and will be jammed by the defending side, while the availability of penetrating ISR capability to support such retargeting remains problematic.
Stealthy cruise missiles such as the JASSM/JASSM-ER offer the best potential for surviving enroute to the target, but their endgame survivability in the last three miles of flight remains questionable, given existing and emerging capabilities in “counter-PGM” optimised point defence weapons. Eight SDBs targeting a single aimpoint are more likely to be successful than one or two cruise missiles, simply due to the saturation of the missile batteries involved.
Weapons with terminal seekers will have to overcome countermeasures deployed by a target system, if the weapon can arrive before the target has redeployed itself, and is not shot down as it approaches the target.
EWSP equipment has been critical to the survivability of Western combat aircraft subjected to SAM attacks. The advent of DRFM based jammers during the 1990s provided much greater potency compared to earlier analogue jammers.
In a modern IADS environment jamming will have to overcome robust Electronic Counter Counter Measures (ECCM/EPM) capabilities in radars and SAM seekers. Russian design philosophy stresses countermeasures resistance, and modern designs employ monopulse angle tracking techniques, frequency hopping, jammer nulling and other techniques. The advent of track fusion techniques will further enhance jam resistance.
No less importantly, most modern Russian radars employ jammer angle tracking techniques, which combined with pervasive networking, will provide missile batteries with an organic capability to target SAMs against jamming aircraft. The potential for alternate SAM seeker types increases this risk.
The integration of passive Emitter Locating Systems into SAM batteries provides at a minimum an ability to overcome jamming, and at worst an organic targeting capability exploiting emissions from the jammer.
Support jamming aircraft have been a priority target since the Soviet era, and the S-300V/SA-12 system had specific angle tracking capabilities designed in for this very purpose during the 1980s. Current Russian thinking is to employ very long range SAMs to kill support jamming aircraft in their standoff orbits. By extending SAM kinematic range past 120 nautical miles, the Russians have driven aircraft using the extant ALQ-99 Tactical Jamming System (EA-6B/EA-18G) outside of the power-aperture envelope where this system performs most effectively , , .
The Next Generation Jammer, if at all implemented, will need to be designed around the realities of long range missile attacks against standoff jamming aircraft.
Stealth remains the ace in the US deck of cards for defeating modern IADS. Unfortunately a belief has developed in parts of the US defence community that “any stealth is good enough”, as evidenced by the ongoing debate surrounding the viability of the Joint Strike Fighter. Unfortunately what might have been true in the world of the 1980s is not true today, as Western aircraft must confront much more powerful and longer ranging radar technology.
Analysis of available performance data for a wide range of modern Russian and Chinese acquisition and engagement radars indicates that at a minimum to survive in a modern IADS a combat aircraft will require an “all aspect” Radar Cross Section in the -35 dBSM to -45 dBSM class, from the L-band through to the Ku-band .
Such performance is demonstrably delivered by only two existing designs, the B-2A Spirit and the F-22A Raptor. The X-47B UCAS and planned New Generation Bomber (“QDR Bomber” or “2018 Bomber”) will, if well designed, fall comfortably within this performance envelope.
The Joint Strike Fighter is not in this class and without a deep, time consuming and very expensive redesign, cannot be .
should not be surprising as it is a design built
to earn export dollars rather than deliver credible and survivable
in the long term. Benefits for the US and other industrial complexes,
capability, may well be politically attractive, but have no place in a
where potential threats have been allowed to outweigh, and increasingly
deterrent capabilities meant to keep the world in balance.
The B-2A Spirit is the only operational type in the US inventory, other than the F-22, which can survive in a modern IADS. Only twenty were built due to the post Cold War budgetary collapse.
The United States and its Allies have relied since the end of the Cold War upon the ability to quickly overwhelm an opposing IADS, and the ability to then deliver massed precision firepower from the air, as the weapon of choice in resolving nation state conflicts.
The reality of evolving IADS technology and its global proliferation is that most of the US Air Force combat aircraft fleet, and all of the US Navy combat aircraft fleet, will be largely impotent against an IADS constructed from the technology available today from Russian and, increasingly so, Chinese manufacturers. If flown against such an IADS, US legacy fighters from the F-15 through to the current production F/A-18E/F would suffer prohibitive combat losses attempting to penetrate, suppress or destroy such an IADS.
The IADS technology in question is currently being deployed by China, Iran, Venezuela, and other nations, most of which have poor relationships with the Western alliance.
Until the US Air Force deploys significant numbers of the intended New Generation Bomber post 2020, only aircraft types in the US arsenal will be capable of penetrating, suppressing and destroying such an IADS – the B-2A Spirit and the F-22A Raptor.
Cruise missile bombardment from standoff ranges is often presented as an alternative to crewed combat aircraft delivering precision bombs. The difficulty, identified earlier, with cruise missile bombardment is that it is most effective against fixed targets, and improving point defence capabilities present a genuine risk that a sizeable proportion of cruise missiles sortied will be shot down as they close on their targets. Another consideration is the aggregate cost of such bombardment, since cruise missiles are still at least an order of magnitude more expensive than guided bombs, making the sustained delivery of thousands of rounds difficult to sustain by production, and fiscally .
Stealthy Uninhabited Combat Aerial Systems (UCAS/UCAV) have also been proposed, specifically for SEAD/DEAD and fixed target strike operations. This technology presents as a better choice than cruise missiles, for economic reasons and the potential for a UCAV to saturate terminal defences with multiple SDBs. While a credible airframe with adequate stealth performance is feasible in the near term, the X-47B presenting as a good example, the remaining components required for a credible capability remain immature, risky and in many respects, problematic. The required range and loiter endurance will require an aerial refuelling capability for the uncrewed system. Satellite downlinks from the vehicle, and line of sight datalinks, will be jammed by an opponent, forcing heavy reliance on autonomous onboard artificial intelligence, and organic ISR capabilities on the vehicle itself, if anything beyond fixed infrastructure targets are to be attacked .
The only low risk technological strategy available to the US in the 2010 – 2020 timeframe is exploitation of existing stealth technology designs, which are as noted earlier, only the F-22A Raptor and B-2A Spirit , , [v].
There are only twenty B-2As in existence and retooling to manufacture a B-2C is an expensive approach given the commitment to the New Generation Bomber .
The United States therefore has only one remaining strategic choice at this time. That strategic choice is to manufacture a sufficient number of F-22A Raptors to provide a credible capability to conduct a substantial air campaign using only the B-2A and F-22A fleets.
The expectation that the US can get by with a small “golden bullet” fleet of stealth aircraft to carve holes in IADS to permit legacy aircraft to attack is no longer credible. The difficulty in locating and killing the new generation of self propelled and highly survivable IADS radars and launchers presents the prospect of a replay of the 1999 OAF campaign, with highly lethal SAM systems waiting in ambush, and mostly evading SEAD/DEAD attacks.
The F-22A Raptor will therefore have to perform the full spectrum of penetrating roles, starting with counter-air, and encompassing SEAD/DEAD, penetrating ISR and precision strike against strategic and tactical targets. The B-2A fleet can robustly bolster capabilities, but the small number of these superb aircraft available will result inevitably in very selective use.
How many F-22A Raptors is enough to meet this capability benchmark? If we assume an aircraft configuration reflecting the planned F-22A Block 40 configuration, and we assume a contingency of similar magnitude to Desert Storm, then the required number of F-22A aircraft to cover the spectrum of penetrating roles is of the order of 500 to 600 aircraft , .
This is making assumptions such that few F-22A aircraft will need to be retained for other duties in other theatres, and that a significant air threat does not exist and thus few F-22A aircraft need to be committed to Defensive Counter Air operations.
From a different perspective, a block replacement of the ~600 strong F-15A-E Eagle / Strike Eagle fleet one for one with F-22A Raptors would provide the proper fleet size.
The United States no longer has any real
this matter, if it wishes to retain its secure global strategic
position in the
2010 – 2020 time window. Any other force structure model will result in
nett loss of strategic potential, and produce strategic risks, which
the US nor its Allies can afford.
[i] There are some indications that the Russians intend to wholly standardise on wheeled vehicles for all of their IADS components. This makes sense insofar as wheeled vehicles are more affordable to buy and maintain, provide higher road speed than tracked equivalents, and produce a less challenging vibration environment for electronic equipment. The Cold War imperative to provide organic air defence for tank armies operating off road has vanished, while the imperative of mobility has increased.
[ii] An argument which sometimes energes in the radar observables engineering community is that power aperture alone is not enough to detect and track targets with an RCS below -20 dBSM, due to impairments such as receiver channel noise floor, master oscillator coherency and phase noise, and limitations in receiver analogue/digital converter linearity, and quantisation performance / dynamic range. While these impairments may well compromise detection performance against very low signature targets, these impairments are also readily reduced by block upgrades to key radar components, block upgrades which are typically much cheaper than transmitter design changes to increase power-aperture performance. Power-aperture performance thus sets the outer bound on the performance of the radar in question, and it is strategically unsafe to assume that over the operational life of such a radar receiver and oscillator upgrades will not be inserted to drive actual detection performance to this physics constrained bound.
[iii] A wider consideration here is that most Western threat warning receivers and aircraft self protection systems do not have coverage extending into the L-band, indeed many systems cut off at around 2 GHz. Much the same is true of anti-radiation missiles. The technological problem is that of the antenna dimensions required to produce useful gain.
[iv] The PLA is known to have experimented with LPI techniques for at least 25 years. They have employed Frequency Modulated Continuous Wave (FMCW) modulations, Frequency Modulated Interrupted Continuous Wave (FMICW) modulations, forms of Pulse Code Modulation, and pseudonoise modulations. The author is indebted to John Wise for his advice in this area.
[v] The B-2A has the radar low observables performance to defeat all of the threat radars in question. However if unescorted it will be limited to night only operations, due to the risk of hostile fighters and weapons with electro-optical guidance regimes, under clear sky conditions. With an adequate number of F-22s available, such that OCA/DCA/SEAD/DEAD escorts can be attached to the B-2A, the aircraft can then be safely flown day or night. Subject to basing distances and turnaround times, this could double the sortie rates achievable by the limited number of B-2As in service.
Imagery Sources: Author; www.jsf.mil, US DoD.
Air Power Australia Analyses ISSN 1832-2433
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