The increasing reliance on attack drones and cruise missiles is challenging the dominating reliance placed on missiles for air defence.
That these have become the preferred means being employed to strike fixed facilities, infrastructure and forward operating bases has created a dilemma in conducting effective air defence.
The relatively low production costs of the drone and cruise missile readily permit their proliferation and mass employment. These factors allow an opponent to launch simultaneous attacks in large numbers.
These mass strikes, often referred to as “swarms”, have the potential to overwhelm air defences. This tactic can be particularly effective against air defences relying on missiles as they are limited in the number of missiles available ready to launch.
In addition, the cost of these missiles can be in the hundred thousands of dollars or even millions while drones may be considerably less. For example, the Iranian Shahed 136 drone is reportedly between US$20,000 and $40,000 while the AIM120 AMRAAM used in the NASAMS is US$1.2 million or the PAC-3 Patriot at US$3-4 million.
Northrup-Grumman is proposing a cannon-based air defense (CBAD) focused on these new threats to complement the current air defence capabilities.
CBAD integrates sensors, battle management command and control, with proven cannon effectors that lever advanced ammunition technologies to provide an effective and cost-efficient layered defence against drones and cruise missiles.
Ryan Carlson, CBAD Chief Engineer and Tech Fellow, explained “the approach provides the mass essential to effectively counter the anticipated large-scale attacks against sites and ships by employing already available cannons”.
Modelling analysis show that cannon bring the advantages of ten to fifteen times greater stowed kills and a cost per effect over 99 percent lower than interceptor missiles.
Guided ammunition, which is currently in development, coupled with enhanced lethality, proximity warheads are key enablers to CBAD. This provides a lethal, cost-effective, and resilient interceptor against a wide range of aerial threats. Capable of multiple, continuous inflight manoeuvres towards threats these munitions increase range, lethality, accuracy, and achieving a kill with a minimum of rounds fired.
Carlson stated CBAD delivers “handfuls of rounds – at intended targets with extreme precision.” Current efforts are modelling and evaluating the best calibres with 30, 40 and 50mm auto-cannon, 57 and 76mm naval guns, and 155mm being investigated.
The former, like Northrup-Grumman’s Bushmaster Series, being current direct fire weapons are established capabilities in this role while adapting the later, more commonly an indirect fire howitzer, may envision some innovation.
However, the debut of turreted truck mounter howitzers, like Rheinmetall’s HX-3 155mm, could offer viable possibilities in such a role.
Still the objective of CBAD is to field an initial capability quickly with minimal development risk. Much of the present effort is being done in a simulated environment with “a lot of mission and campaign-level analyses”. Still a number of its potential elements have, in fact, been either fielded or field-tested.
For example, the ability of the Mk44 30mm Bushmaster auto-cannon using proximity ammunition in its MACE had already established its effectiveness against tactical drones.
Thus, the company projects that demonstration of an initial CBAD capability could occur within a year.
It is conceivable that production of a variety of gun kits and rounds could be available in a few years.
by Stephen W. Miller
