In the first half of the twentieth century, guns were the primary weapons used against aircraft. The small arms weapons typically fire ball ammunition, or armor-piercing projectiles, known as AP rounds, or AP projectiles with incendiaries, known as API rounds. The AAA weapons and the larger-caliber aircraft guns usually fire ballistic projectiles with a high-explosive (HE) core and a surrounding metal case. These are referred to as HE warheads or HEI warheads when incendiaries are included. After World War II, guided missiles, both surface-based and airborne, were developed to kill aircraft. These anti-air weapons typically carry contact- or proximity-fuzed HE warheads designed to kill aircraft with fragments and blasts.
Current aircraft have become vulnerable to sophisticated networked surface-to-air missile batteries produced by Russia and China, which could destroy early warning aircraft, tactical fighters, and even stealth bombers. The proliferation of surface-to-air missiles and long-range tactical missiles reduces the area where U.S. forces can operate. China reportedly has received its second set of S-400 surface-to-air missile systems from Russia, marking a potentially major improvement of the country’s air defenses.
Survivability is defined as the capability of a system, including its crew, to avoid or withstand a hostile environment without suffering an abortive impairment of its ability to accomplish its designated mission. With the development of precision-guided weapons, particularly radar-guided missiles and infrared-guided missiles, aircraft combat survivability is becoming increasingly important. Eastern Ukraine incident in 2014 demonstrated the vulnerability of aircrafts where a passenger jet was downed by a surface-to-air missile, killing all 298 people aboard, and fired from territory held by pro-Moscow separatists.
With rising threats new technologies are being devised to enhance the survivability of aircrafts from Advanced Threat Detection/Avoidance Components and Techniques, laser directed energy weapons, Electronic Warfare Countermeasure Systems and Techniques to cyber warfare are being developed. Aircraft survivability relies on a hierarchy of stages to return the aircraft to service. If an aircraft cannot avoid detection, it should try to avoid engagement. If the aircraft is engaged, it should then try to avoid or absorb damage, and if all else fails at least attempt to avoid destruction.
Decoy, deceptive device used to draw an enemy away from a more important target. Active decoys are the principal method of self-defense for military aircraft and intercontinental ballistic missiles (ICBMs). Passive decoys, or dummies, are used to deceive visual intelligence such as photo-reconnaissance.
However, the first and most obvious lesson of the Armenia-Azerbaijan war is that through massed unmanned aircraft systems (UAS), it is possible for ground forces to cheaply replicate elements of a robust air force at a localized level. As demonstration of this, the Azerbaijanis used loitering munitions (kamikaze drones), medium-strike UAS with guided munitions, and recon UAS in concert with artillery, to devastating effect. Against an entrenched opponent, the strikes decimated the fixed command posts, logistics centers, and assembly areas, badly weakening Armenian defenses.
At the onset of the conflict, Azerbaijan leveraged Soviet-era AN-2 biplanes to deceive and expose Armenian air defenses. Though decades old and intended to serve as traditional manned aircraft, the biplanes’ conversion to unmanned decoys allowed Azerbaijan to conduct low altitude flights into the highly contested environment—and more importantly—into the weapons engagement zone (WEZ) of Armenian air defenses. These improvised UAS were repurposed as decoys and flown to the front lines to force air defenses to give away their location and enable targeting by TB2s.
When the Armenian air defenses targeted, engaged, and destroyed the perceived threats, they inadvertently broadcasted their positions to Azeri unmanned aerial attack platforms that flew at higher altitudes—enabling the Bayraktar TB2 and kamikaze drones to destroy higher-payoff targets like the Armenian air defense systems.
Miniature Air-Launched Decoy (MALD) and Miniature Air Launched Decoy – Jammer (MALD-J)
The Miniature Air-Launched Decoy, or MALD® decoy, is a low-cost, expendable, air-launched craft that deceives the most advanced enemy integrated air defense systems while keeping pilots and aircraft out of harm’s way. The programmable weapon duplicates the combat flight profiles and signatures of U.S. and allied aircraft.
Operators send a formation of the MALD decoys into hostile airspace. The flexible, modular systems fly a preprogrammed mission that protects allied aircraft while confusing enemy integrated air defense systems. Each craft weighs less than 300 pounds and has a range of around 500 nautical miles.
In 1999, the first flight test associated with the Miniature Air-Launched Decoy (MALD) program, which begun in 1995, took place. With origins in the tradition of metal radar-confusing chaff dropped from aircraft, the point of MALD was to develop a small, inexpensive decoy missile to counter air defense measures. The ADM-160A, the designation of the initial system to emerge from the program, carried electromagnetic components capable of simulating virtually any aircraft.
Once launched, the AGM-160A’s wings would pop out and its turbojet engine would ignite. It would then autonomously fly a pre-planned route and mimic a specific radar signature via its Signature Augmentation System (SAS). The SAS could accurately replicate radar signatures ranging from a lumbering B-52 Stratofortress to a stealthy F-117 nighthawk.
These decoys would then trigger the adversary air defense systems to turn on their radars to track and engage them. This will not only enhance the survivability of Aircrafts but will enable electronic intelligence gathering aircraft like RC-135′ Rivet Joint’ to record, locate and categorize that enemy’s electronic order of battle- where their SAM sites and air defense nodes are and how they react to certain perceived threats, from a standoff and safe distance. This collected data from a ‘pre-attack’ will provide accurate location for the follow-on attack of High Speed Anti-Radiation Missiles (HARMs) or PGMs.
Although the ADM-160A did not directly evolve into fielded systems, management of the effort was subsequently picked up by the Air Force and follow-on efforts led to production models of what became known as MALD-J. This new, larger and reinvigorated MALD program moved swiftly, with the first larger AGM-160B being delivered to the USAF in 2009.
The MALD-J decoy is the jammer variant of the basic decoy and the first ever stand-in jammer to enter production. The unmanned system can operate alone or in pairs, and moves much closer to the victim radar than conventional electronic warfare when jamming electronics. It’s able to loiter in the target area, allowing plenty of time to complete the mission.
Saab Electronic Warfare and electronic attack decoys
Saab has unveiled details of a future fast jet airborne electronic attack (AEA) capability concept combining a high-power escort jamming pod, long-range air-launched decoys, and advanced electronic warfare (EW) operator control and fusion techniques. Outlining an increasingly complex and challenging anti-access/area denial (A2/AD) environment, Jonas Grönberg, the company’s Head of Product Management for Fighter EW, argued that the emergence of new low-band early warning radars means “low observability is no longer a substantial defence for strike aircraft”, advocating instead “high-powered electronic attack to deny shared situational awareness and targeting data, and to negate data networks”.
Saab in 2013 began its in-house study to characterise the future air operating environment so as to inform key requirements and technologies for combat aircraft in the 2035–40 period. One key conclusion to emerge from this work was the requirement for a credible AEA capability, supporting suppression of enemy air defences/destruction of enemy air defences, to improve aircraft survivability, and enable penetration of the A2/AD screen. “It turned out that EW came out as a common enabler,” Grönberg told Jane’s in a subsequent interview. “The survivability of any platform will require much enhanced EW capabilities. Even the latest low observable technology will not render an aircraft invisible.”
Central to Saab’s thinking is the development of a self-contained (in cooling and power) electronic attack (EA) pod suitable for two-seat variants of the JAS 39 Gripen or other twin-crew fighter aircraft. EA pod concept studies and design, including the build of engineering mock-ups, have been founded on the reuse of technology building blocks previously developed for the Gripen E’s internal self-protection EW suite. The pod design developed by Saab incorporates VHF and UHF antennas in fin surfaces, with L-band and S-band active electronically scanned array antennas, based on gallium nitride technology, fitted front and rear.
The second element of the triad is a miniature air-launched decoy to perform both distraction and stand-in jamming. Saab has conceptualised a small, long-range, long-endurance decoy vehicle with an EW payload that can locate and identify threats and targets, and distract enemy air defence resources. The decoy will support an attack on a target defended by surface-to- air missile systems by acting as a stand-in jammer.
The third piece of the new concept is the development of a back-seat electronic warfare officer (EWO) station embodying advanced sensor data fusion and decision support techniques. Saab has already prototyped the EWO human machine interface in the simulator, and has shown it to the Swedish Air Force
Propulsion technology for active decoy missiles
The U.S. Air Force is looking at the potential of pulsejet technology as part of broader efforts to provide reliable, low-cost powerplants for future drones and missiles. The service is kicking off its new foray into pulsejets by funding the development of a new air-launched decoy drone.
A pulsejet — so-called because its combustion occurs intermittently, in pulses — has few or no moving parts, in contrast to a conventional jet. Fuel and air are combusted within a simple hollow tube, and hot gases are pushed out of the back to produce thrust. This confers on them the advantages of simplicity and light weight, but on the other hand, they traditionally have a poor compression ratio, which limits their power output. They are also typically very loud.
The Air Force Armament Directorate recently awarded the Wave Engine Corporation startup a $1-million contract to develop and then demonstrate the pulsejet decoy, known as the Versatile Air-Launched Platform (VALP). The award followed what the company describes as a “highly competitive process with hundreds of applicants” as the Air Force seeks to fund promising new technologies for possible use in future capabilities.
The company statement talks about “jet performance” and confirms that its pulsejet uses Full Authority Digital Electronic Control (FADEC), in which a computer controls engine performance. On its website, the firm claims that it can now offer Thrust Specific Fuel Consumption (TSFC) that’s “competitive with turbine (jet) engines.” “Wave Engine Corp.’s technology enables an order-of-magnitude reduction in the cost and complexity of jet propulsion, making it practical for a wide variety of aviation platforms for which jet propulsion was previously cost-prohibitive,” the company says.
The limited description suggests a role similar to the existing ADM-160 Miniature Air-Launched Decoy (MALD), which is dropped by aircraft and operates much like a mini-cruise missile, albeit designed to distract and deceive enemy air defense systems to protect a strike package. The ADM-160 is powered by a small turbojet engine.
“VALP is a multi-mission, air-launched vehicle that leverages the company’s proprietary engine technology to demonstrate high-performance, low-cost propulsion for future generations of high-performance aerial vehicles,” Wave Engine said in a statement confirming the contract award. “The future of aircraft is smaller, more capable, and more affordable,” explained Daanish Maqbool, CEO of Wave Engine. “The aviation industry has long been stymied by the lack of high-performance engines for small aircraft, and we are here to break through this barrier.”
The company’s pulsejet technology has already received investment from the U.S. military, with a $3-million award from the Defense Advanced Research Projects Agency (DARPA) in 2019 that led to successful flight demonstrations in 2020. These involved a pulsejet mounted above the fuselage of a manned glider.
Clearly, if the pulsejet proves itself in a decoy, there is potential to migrate the same technology into other vehicles, such as drones or cruise missiles. The low cost of these engines would make it especially suitable for missiles as well as attritable drones that are not necessarily expected to complete more than one mission.
References and Resources also include: