Dynamically Directional Self-Protection CMDS Testing

by David Luschen and Christer Zätterqvist

U.S. Navy Photo by MC2 Madison Cassidy

Military helicopters today operate within a full spectrum of operations, from peacekeeping activities to combat missions. Many of these operations require these aircraft to fly close to the ground at slow speeds or in hover, making them inherently susceptible to a wide range of threats [1]. Accordingly, the continual advancement and global proliferation of advanced man-portable air defense systems (MANPADS), air defense artillery (ADA), and surface-to-air missile (SAM) systems remains the biggest lethal threat to rotary-wing operations on current and future battlefields [2]. In addition, unguided anti-aircraft weapons pose a unique problem, as currently fielded aircraft survivability equipment (ASE) is dependent upon threat weapon guidance.

In the current conflict in Ukraine, we have seen the vulnerability of Russian helicopters to attack from both guided and unguided antitank weapons. This ongoing, real-world example underscores the fact that rotary-wing ASE must keep pace with the operational environment and that continual advances in ASE capability and performance are critical to reducing the potential loss (or costly repair) of rotary-wing (and fixed-wing) platforms, the loss of the aircrews within them, and the loss of the overall operational capability of U.S. and allied forces.

BACKGROUND

To date, the focus of most ASE development improvements has been centered around enhancements to existing decoys, as well as the addition of new types of expendable infrared (IR) countermeasure (CM) decoys and expendable radio frequency (RF) chaff decoys. For example, expendable IR flares were originally thermites based on magnesium/Teflon/Viton (MTV); as such, they are known as MTV compositions [3]. Now, due to significant advances in technology, including multi-mode seekers [4], new flares have been added to the inventory, such as kinematic, spectral, aerodynamic, contrast, and visual distraction flares, which are all available to keep pace with the evolving threat.

For the operator and aircrew, these advancements mean that there is increasing competition for already-limited countermeasure dispenser systems (CMDS) decoy capacity on any given military platform. Separately, there are other ongoing efforts that continue to improve the performance of RF jamming systems and defensive directed-energy systems. Only recently have capability and capacity improvements to legacy and future CMDS been considered and undertaken.

It is important to note that much of the recent innovations in CMDS capabilities have centered around the January 2022 ratification by participating NATO nations of STANAG (Standardization Agreement) 4781 Defensive Aids System (DAS) Open Architecture and Allied Engineering Publication (AEP) 104 NATO Defensive Aids System (NDAS) Open Architecture [5]. NDAS is an enabling element of an integrated DAS architecture, which, when combined with platform DAS sensors and effectors (such as missile warning systems and CMDS expendable decoys), supports enhancements in platform protection in an increasingly contested and congested spectral environment. This new STANAG is managed by a Custodian Support Team under NATO Aerospace Capability Group 3, Subgroup 2 (ACG3 SG/2).

Aerospace and defense company Saab is playing a significant role in maturing the concepts for a workable approach for the Smart Stores Communication Interface (SSCI) and the DAS Functional Communication Interface (DFCI). The company is also developing a next-generation CMDS—the Dynamically Variable Magazine (DVM) (pictured in Figure 1)—which provides for 2 degrees of freedom (DOF) (azimuth and elevation) for expendable CM dispensing vs. the traditional approach of having a fixed CMDS magazine mounted to an air platform. The capability to dispense expendables in any direction provides significant performance improvements to legacy decoys, which can be properly aimed and dispensed based upon threat angle of arrival.

Figure 1. DVM Used During Testing.

This advanced technology is effectively bridging the gap between soft-kill CMs and hard-kill CMs to address unguided threats and hard-to-defeat guided threats, thereby increasing overall platform survivability. Soft-kill CMs include IR expendable decoys, RF chaff decoys, and radar jammers. Hard-kill systems detect, engage, and destroy or neutralize an incoming threat before it can hit a protected air platform by actively firing CM projectiles to intercept the threat. A new CMDS that has the capability to aim and dispense Threat Agnostic Countermeasures (TACM) is an integral part in Saab’s system, which is specifically designed for rotary-wing and fixed-wing platforms.

PROTOTYPING

DVM technology exploration and development started in 2016, with an emphasis placed on functional stability under real-life conditions and the completion of several ground-based live firing trials. Driven by customer and industry collaboration, DVM can fire expendables dynamically in-flight in selectable directions using currently installed platform sensor inputs to maximize survivability against difficult threats. DVM is an emerging dispenser technology for enhanced self-protection or offensive capability by dynamically changing dispense angles, rotation rates, blanking zones, sequences, timing, quantities, and types of effectors for optimal performance. In addition, DVM is designed to be supplementary to already-installed ASE and similar to already-installed dispensers.

The DVM solution, which is controlled by a central dispenser programmer over a Sequencer Data Link (SDL) or through means described in STANAG 4781, leverages proven electromechanical and pyrotechnical dispenser technologies. It also leverages input from existing on-board sensors. This will allow the DVM to provide target directional information and command from the CM dispenser programmer, as well as aim and perform CM actions in a desired direction to achieve one or more objectives, including, but not limited, to the following:

Dispensing flares in an optimum direction
Dispensing chaff in an optimum direction
Dispensing Expendable Active Decoys (EAD) in an optimum direction
Dispensing ultraviolet (UV) CMS (to counter threats with UV seekers)
Dispensing hard-kill anti-rocket-propelled-grenade (RPG) countermeasure munitions (CMMs) (i.e., warhead and/or kinetic munitions).

TESTING

As further investments in DVM development have been made, the latest testing in January 2023 was successfully performed to advance the technology readiness level (TRL) to TRL 6 (prototype demonstration in a relevant environment). DVM testing was performed in an outdoor arena to safely record and evaluate the functions and performance of the system by conducting firing tests of NATO standard pyrotechnical flares supplied in a 1-inch by 1-inch by 8-inch format. Flares with different flight trajectories and recoil forces used were as follows:

DSTL22 (1-inch by 1-inch by 8-inch aerodynamic)
L7A7 (1-inch by 1-inch by 8-inch kinematic)
CM118 Mk3 Type 1.

The DVM-200, which was used for the tests, has a system architecture that will facilitate an installation onto a variety of platforms. The system comprises the following major subsystems:

Figure 2. The Ground Firing Test System Setup.

Dispenser Unit – includes the electromechanical drive mechanisms, the magazine for loaded decoys, and the support infrastructure for listed functions
Electronic Box – includes the internal power supply, control electronics, and operational software
Command Box – includes the operator interface with respect to indicator light-emitting diodes (LEDs) and switches for discrete control signals in a manner equivalent to a cockpit control.

In addition, the system includes numerous robust safety features, including a safety pin and a safety key, which are required for enabling the motors and firing signals. The ground test configuration (shown in Figure 2) also includes an emergency stop.

Figure 3. Firing Angles Used During Testing.

Figure 3 depicts the firing angles used during testing and how the range in elevation movement can be limited by mechanical stops for three different angular ranges: 0°–180°, 0°–127°, and 27°–154°. The possible range in azimuth is 0°–360°; however, 270°– 90° was used during the tests.

Data recording and measuring equipment included a high-speed camera for close-in capture of DVM angular movements. Several GoPro cameras were present to capture flare trajectory and firing sequences, as well as an airborne drone camera for recording firing sequences and microphones for sound measurements. In addition, recoil force sensors were used to capture recoil and set-back forces created by each dispense sequence.

Horizontal dispense sequences (shown in Figure 4) captured lateral DVM movement with constant elevation, and diagonal dispense sequences (shown in Figure 5) captured DVM movements in both azimuth and elevation.

Figure 4. Horizontal Dispense Sequence of Five Expendables.

Figure 5. Diagonal Dispense Sequence of Five Expendables.

A mass-representative inert decoy with boresight laser diode was used to perform angular precision tests. To verify the speed of DVM angular movements (shown in Figure 6), markings on the DVM were captured from video recordings from the high-speed camera.

Figure 6. Rapid Firing at Two Different Targets.

Proximity sequences (shown in Figure 7) were used to mimic a scenario in which threats are defeated by effectors equipped with proximity fuzes. Those sequences appeared as tight groupings in the sky.

Figure 7. Proximity Sequence.

CONCLUSION

All test objectives during the January 2023 testing were successfully met. The next step in maturing the DVM technology (from its current TRL 6 status) will be to install the system on an air platform and perform platform compatibility testing and effectiveness testing against various threat systems of concern.

In summary, via a series of laboratory and firing-range testing, the DVM has shown itself to be a proven solution for providing airborne platforms with the ability to dispense various expendables and effectors in specifically commanded directions and to maximize effectiveness against both guided and unguided threats. As such, it represents a significant technological and tactical advantage over standard fixed dispensing systems and increased survivability for a wide range of aircraft and their crews.

ABOUT THE AUTHORS

David Luschen is currently a business development manager for Saab, Inc. Previously, he was a member of the Science and Technology Team of the NAVAIR PMA-272 Advanced Tactical Aircraft Protection Systems Program Office, working with the Airborne Expendable Countermeasures Branch and the Air Countermeasure Dispensers Branch. Mr. Luschen is also a former Navy F-14A radar intercept officer, a Navy Fighter Weapons School graduate, and a former electronic warfare officer. He holds degrees in aerospace engineering from the University of Texas and an MBA from the University of West Florida.

Christer Zätterqvist currently works in business development for Saab AB, Sweden. He has 32 years of experience in the airborne self-protection domain and has held positions such as mechanical engineer, systems engineer, engineering lead, technical advisor, project manager, product manager, and head of product management. Mr. Zätterqvist holds a degree in mechanical engineering from Fyrisskolan in Uppsala, Sweden.

References

[1] Muspratt, Adam. “Future Military Helicopters: Survivability, Threats and Autonomy (Interview).” Defence IQ, https://www.defenceiq.com/air-forces-military-aircraft/articles/future-military-helicopters-survivability-threats-and-autonomy-interview, 14 January 2019.

[2] U.S. Department of State. “MANPADS: Combating the Threat to Global Aviation from Man-Portable Air Defense Systems.” https://2009- 2017.state.gov/t/pm/wra/c62623.htm, 11 July 2011.

[3] Douda, Bernard. “Genesis of Infrared Decoy Flares.” First Edition, Naval Surface Warfare Center, Crane Division, https://apps.dtic.mil/sti/ pdfs/ADA495417.pdf, 26 January 2009.

[4] Army Technology. “Verba 9K333 Man-Portable Air Defence System (MANPADS).” https://army-technology.com/projects/verba-9k333-man-portable-air-defence-system-manpads/, 16 March 2016.

[5] Scott, Richard. “NATO Defensive Aids System STANAG Ratified.” Journal of Electromagnetic Dominance, https://www.jedonline. com/2022/04/18/nato-defensive-aids-system-stanag-ratified/, April 2022.