Air-MALD-J
Raytheon ADM-160C decoys are seen here on the underwing hardpoints of this Boeing B-52H Stratofortress strategic bomber. The ADM-160C will form the basis for the US Navy’s new MALD-N decoy.

Raytheon’s ADM-160 MALD decoy and jammer is celebrating its silver jubilee. The US Navy is joining the party.

It is 25 years since the US Defence Advanced Research Projects Agency launched its effort to acquire an air-launched decoy which could assist air defence suppression. Initially, the legendary Teledyne Ryan (now Northrop Grumman) picked up the baton, developing the ADM-160A which entered flight testing in 1999 completing this two years later. All was set for the US Air Force to acquire thousands of ADM-160As, but the air force’s initial dissatisfaction with its endurance and range scuppered the programme triggering its cancellation in 2002.

Miniature Air-Launched Decoy (MALD)

This did not end the Miniature Air-Launched Decoy (MALD) story. The initiative was revived that same year with the commencement of an effort to procure a new version of the MALD design but meeting the USAF’s range and endurance criteria. Raytheon won the competition with its design for the ADM-160B. This took the baseline ADM-160A design, outfitting it with a more powerful Hamilton Sundstrand TJ-150 turbojet in place of the company’s original TJ-50, and a larger airframe. Deliveries commenced in 2009 with the USAF pledging to purchase around 1,500 examples.

The MALD architecture employs a fiendishly simple principle. The decoy carries an RF emitter which can be tuned to several frequencies used by ground-based air surveillance and fire control/ground-controlled interception radars, and airborne fire control radars. The decoy will then transmit waveforms designed to show up on the hostile radar as a particular plane such as a Boeing B-52H Stratofortress strategic bomber or General Dynamics/Lockheed Martin F-16 Fighting Falcon series combat aircraft. The ADM-160B received a further enhancement last decade with the addition of a jamming payload resulting in the ADM-160C MALD-J design delivered to the USAF from 2012. Once ADM-160B rounds are expended, the ADM-160C will be the only MALD variant in the USAF inventory.

The advent of the ADM-160J was an important development. The ADM-160B was arguable an aircraft self-defence system, albeit a highly sophisticated one, intended to protect a plane from a radar’s hostile gaze. The ADM-160C enables the MALD concept to support air defence suppression, with the loitering electronic attack capability safeguarding strike packages of aircraft while in the vicinity of such radars. One Concept of Operations (CONOPS) could see ADM-160Cs being used in cooperation with Raytheon/Northrop Grumman AGM-88E/F advanced variants of the Raytheon AGM-88B HARM (High-Speed Anti-Radiation Missile) with some radars being jammed by the ADM-160C and the most threatening kinetically engaged with the AGM-88E/Fs.

Technical specifics of the ADM-160B are sparse, although it is seems certain that the decoy uses a Digital Radio Frequency Memory (DRFM) and can sample incoming radar signals, demodulate these, re-modulate them in such a way as to mimic the echo generated by a particular aircraft’s radar cross section, and then retransmit this back to the radar. The addition of the electronic attack payload to the ADM-160C may allow the system to transmit spot or barrage jamming waveforms against radars transmitting across frequencies of at least two gigahertz to 18GHz. This would cover the lion’s share of wavebands used by the radars mentioned above. Once again, the DRFM could be brought into play to transmit sophisticated jamming waveforms using range gate and velocity gate pull-off techniques to deceive a radar as to the position and speed of a target.

MALD-N

While the ADM-160B/C has been the preserve of the US Air Force, the US Navy has shown interest in the MALD concept and is moving ahead with the MALD-N. In March it was announced that the US Naval Air Systems Command had authorised production of the MALD-N with a low rate initial production contract to be awarded to Raytheon’s missile systems business. The contract is expected to support the initial production of up to 250 MALD-N decoys, as the naval variant is known, by 2022 according to US government documents. The few additional details released regarding the capabilities of the MALD-N reveal that this will use the ADM-160C design but may include an adaptive electronic warfare payload, and a datalink. This should allow the decoy to receive real-time updates regarding the electronic order-of-battle in its locale and update its jamming schemes accordingly. For instance if an Almaz-Antey 9K330 Tor (NATO reporting name SA-15 Gauntlet) low-altitude, short/medium range surface-to-air missile system is detected entering the theatre of operations it may be possible to automatically upload the jamming waveforms necessary to defeat the 9K330’s 9K331 Scrum Half S-band (2.3GHz to 2.5GHz/2.7GHz to 3.7GHz) engagement and fire control radar. This suggests that the jamming waveforms used by the ADM-160C may have to be uploaded prior to a mission.

According to a written statement supplied to Armada Analysis by Raytheon the MALD-N will be integrated onto the US Navy’s Boeing F/A-18E/F Super Hornet combat aircraft, deepening the platform’s self-protection. Regarding concepts of operations, the navy may choose to have its Boeing E/F-18G Growler electronic warfare and air defence suppression jet deploying their EDO/L3Harris AN/ALQ-99 and successor Next Generation Jammer electronic attack payloads against radar threats at stand-off and stand-in ranges, and kinetically engaging the most immediate threats with AGM-88E missiles when escorting a strike package. The MALD-N could be used to provide enhanced protection for individual, or small groups of aircraft while in contested airspace.

The company sees growth potential for the decoy dubbing the product as “the first instantiation of an advanced decoy capability that is designed with modularity in mind.” Further improvements could include enhanced jamming and payloads intended to address new threats as they emerge, “it is also feasible to build a MALD with significantly more endurance,” the statement adds. Raytheon foresees increasing the MALD’s endurance, integrating it onto more platforms, including rotorcraft and unmanned aerial vehicles, and potentially adding a rocket booster to the design to enable the decoy to be surface launched.

by Dr. Thomas Withington