Suppressive Fire

The ECRS Mk.2
The ECRS Mk.2 promises a step change for the RAF’s Tranche-3 Typhoons. The radar’s ability to transmit electronic attack, and possibly cyber warfare, waveforms makes it a potent air defence suppression weapon in its own right.

The Royal Air Force is once again embracing the air defence suppression mission courtesy of two fledgling capabilities expected to enter service this decade.

At was 0210 Baghdad time on 16 January when two Royal Air Force (RAF) Panavia Tornado GR.1 ground attack aircraft left runway 06/13 at the Royal Saudi Air Force’s Tabuk airbase, northwest Saudi Arabia. The air campaign of Operation Desert Storm, being waged by a United States-led coalition to evict Iraq from its occupation of Kuwait began just under 30 minutes later.

At 0237 Task Force Normandy, a package of US Army McDonnell Douglas/Boeing AH-64A Apache helicopter gunships escorted by two US Air Force Sikorsky MH-53J Pave Low special forces helicopters attacked Iraqi Air Force (IAF) P-18 (NATO reporting name Spoon Rest) Very High Frequency (VHF: 133 megahertz/MHz to 144MHz/216MHz to 225MHz) and P-15 (Flat Face) Ultra High Frequency (UHF: 420MHz to 450MHz/890MHz to 942MHz) ground-based air surveillance radars just behind the Iraqi-Saudi border. The radars were destroyed depriving the Iraqi Integrated Air Defence System (IADS) of most radar coverage above the west of the country. This shielded the incoming armada of coalition aircraft inbound to attack strategic targets as the conflict’s overture.

The two Tabuk Tornado-GR.1s joined up with a four-ship package of the same aircraft which had left their bases elsewhere in the Kuwaiti theatre of operations bound for the IAF’s Al Asad airbase, central Iraq. This was attacked with the Hunting Engineering JP-233 airfield denial weapon, the first time it had been used in anger. Another weapon was also debuting that night. It was deployed by the two Tornado-GR.1s which had departed Tabuk.

The British Aerospace/MBDA Air Launched Anti-Radiation Missile (ALARM) was developed during the Cold War to attack Soviet Union and Warsaw Pact ground-based air surveillance and fire control/ground-controlled interception radars. The Cold War was concluding, but Iraq had procured several of the same radars ALARM was designed to attack during any conflict in Europe pitching the North Atlantic Treaty Organisation (NATO) and the Warsaw Pact against one another. Systems like the SNR-75 (NATO reporting name Fan Song) S-band (2.3 gigahertz/GHz to 2.5GHz/2.7GHz to 3.7GHz) and P-35M/37 (NATO reporting name Bar Lock) C-band (5.25GHz to 5.925GHz) series of ground-based air surveillance radars were supplied to Iraq by the Soviet Union and were among the radars ALARM was designed to find and kill.

Readers can learn more about the missile in the author’s article entitled ‘When They Sounded the ALARM’ posted on the Armada International electronic warfare website. Suffice to say that it performed with aplomb hitting Iraqi radars providing fire control to surface-to-air missile and anti-aircraft artillery batteries deployed to protect airfields and other targets being attacked by the Tornado GR.1s and other coalition strike packages.

Spreading Alarm

ALARM had a long and distinguished career. The weapon was subsequently deployed to support the RAF and coalition allies during every major air campaign involving the RAF where adversary Ground-Based Air Defences (GBAD) posed a clear and present danger. It won further accolades in the skies above the Balkans supporting the NATO’S 1995 Operation Deliberate Force and 1999 Operation Allied Force, both mounted to bring an end to the genocide blighting the former Yugoslavia. An upgraded version of the missile returned to Iraq in 2003 supporting Operation Telic, the UK’s contribution to Operation Iraqi Freedom, the US-led effort to remove Iraq’s dictator Saddam Hussein from power. Less than ten years later it was in action once more supporting the combined NATO and US operations Odyssey Dawn and Unified Protector waged in 2011 to protect Libyan civilians from forces loyal to that country’s dictator Colonel Muammar Gaddafi.

The missile retired in 2013 and it appeared that the air force’s ability to perform air defence suppression retired with it. True, the RAF could perform Destruction of Enemy Air Defence (DEAD) missions by which conventional kinetic effects are brought to bear against elements of an IADS or GBAD on the battlefield. Yet ALARM’s retirement meant the RAF was bereft of the unique suppressive qualities that this weapon could bring, chiefly encouraging radars to remain off the air without the blue force necessarily knowing where those radars are. Sometimes launching a few anti-radar missiles pre-emptively to protect a strike package which are detected by red force radar operators persuades the latter to switch off their equipment. DEAD is a vital mission but is dependent on knowing where the IADS or GBAD targets are you wish to strike.

A duet of Tornados seen here with ALARM rounds mounted on their inner underwing hardpoints. Earning its spurs during Operation Desert Storm the missile served with distinction until its retirement in 2013.


The good news is that the RAF will soon be back in the air defence suppression game, thanks to two new capabilities it is expected to receive in the future. The first is an electronic attack function to augment the new BAE Systems/Leonardo ECRS Mk.2 X-band (8.5GHz to 10.68GHz) fire control radar destined to equip the Tranche-3 variants of the RAF’s Eurofighter Typhoon FGR.4 combat aircraft. The second is the MBDA Select Precision Effects At Range Capability-Electronic Warfare (SPEAR-EW) loitering electronic attack system. Both effectively perform a similar function to ALARM but do so electronically.

One of ALARM’s attributes was that it could be used pre-emptively. The weapon’s flight profile meant that it could be launched at high-speed and low altitude when a jet was doing its best to stay below radar coverage. Once launched the missile would climb to 40,000 feet (12,192 metres). This gave its radar seeker a ‘God’s Eye’ view of the terrain below. The missile would switch off its motor, deploy a parachute and fall leisurely to earth. Should any radar be foolish enough to illuminate it would immediately betray its presence. The emission would be detected by ALARM’s seeker, the parachute jettisoned and zoom towards the radar like a rat up a drainpipe.

The beauty of ALARM was that it could be used sans pre-briefed targets. The electronic attack function of the ECRS Mk.2 could work in such a fashion. The electronic support measure equipping the Typhoon’s EuroDASS Praetorian integrated defensive aids subsystem can detect a hostile radar when it transmits. Having betrayed its presence the ECRS Mk.2 could be used to electronically attack that radar. Details on the precise workings of these electronic attack function are understandably sparse and probably highly classified. Nonetheless, these capabilities are all but certain to include conventional noise and jamming waveforms transmitted by the radar, alongside discreet waveforms generated by the Digital Radio Frequency Memory (DRFM) embedded in Praetorian. DRFMs sample an incoming hostile radar transmission, manipulates this transmission and then send the signal back to the radar. This manipulation changes the original radar waveform in such a way as to convince the hostile radar that the illuminated aircraft is in another part of the sky, is flying at a different speed or altitude, or is one of several non-existent jets. The subtle manipulation of the original signal ideally leaves the radar none the wiser to the fact that the information it is receiving which it believes to be a radar reflection from the target is false.

As the ECRS Mk.2 has an active electronically scanned array it can electronically steer its electronic attack beams across a wide angle, probably in excess of 60 degrees either side of the antenna’s boresight. This can mean that off-boresight radars can be attacked. This is particularly important as it allows the injection of an electronic attack into a radar’s sidelobes. Smaller radar beams fan out either side of the main axis of a radar’s transmission. These residual transmissions can be detected by an electronic support measure without the aircraft necessarily being in the radar’s field of view.

Unlike an anti-radar missile, an electronic attack can be instantaneous upon detection of a hostile radar and travels at the speed of light. This augmentation of the Typhoon’s radar will be particularly useful at stand-in distances when the aircraft is within the detection range of a hostile radar. Given that several radars can be jammed with several beams from the same antenna, this means multiple radars could be engaged simultaneously.

Spear of Destiny

Air defence suppression will also be performed by the SPEAR-EW, an electronic attack version of MBDA’s SPEAR-3 air-to-surface missile. The weapon’s warhead is removed and replaced with an electronic attack payload. SPEAR-EW could outfit the RAF’s Typhoon and Lockheed Martin F-35B Lightning combat aircraft. Like the electronic attack attributes of the ECRS Mk.2, the frequencies jammable with the SPEAR-EW are under wraps, but it is reasonable to assume these could encompass frequencies of 8.5 gigahertz/GHz to 40GHz. This covers X-band (8.5GHz to 10.68GHz), Ku-band (13.4-14/15.7-17.7GHz), K-band (24.05 to 24.25GHz) and Ka-band (33.4GHz to 36GHz) ground-based air/naval surveillance and fire control radars, plus missile radar seekers. SPEAR-EW will work as an escort jammer performing electronic attack at stand-off and stand-in ranges to protect packages of aircraft. The SPEAR-EW will generate conventional and discreet jamming waveforms, while acting as a decoy to draw air defence attention away from other aircraft.

MBDA’s SPEAR-EW is an electronic attack variant of the company’s SPEAR-3 air-to-surface missile. This is designed to work as a stand-off and stand-in jammer.

Although not mentioned in discussions of the SPEAR-EW or ECRS Mk.2 it would not be surprising it both capabilities retained cyber attack attributes. Today’s and tomorrow’s IADS and deployed GBAD, and constituent components like radars and command and control systems are entirely dependent on computers and internet protocol networks. There is every possibility that the electronic attacks which both will perform could be modulated to include malicious code to infect or exploit the data traffic integral to the smooth running of an air defence system.

The UK Ministry of Defence (MoD) has still yet to place an order for the SPEAR-EW, although once this occurs, the weapon could enter service from the middle of this decade. For now, sources close to the SPEAR-EW programme have said that development continues apace. Likewise, open sources note that the ECRS Mk.2 could enter service with the Tranche-3 Typhoons from 2025.

The advent of both will not only resurrect RAF SEAD capabilities, but improve them immeasurably from the days of ALARM for the wars of tomorrow. Harnessing electronic effects to substitute kinetic effects when possible enhances precision, reduces ordnance expenditure and lowers the risk of collateral damage. It also improves the ability of the RAF to manoeuvre in the spectrum to achieve electromagnetic superiority and supremacy, something indispensable to success in all domains of warfare.

by Dr. Thomas Withington