APKWS: How to make a dumb rocket smarter

Imagine you’re an attack helicopter pilot or ordnance manager.

Your inventory of weapons consists largely of dumb, unguided missiles, rely largely on the targeting skills and dead reckoning of pilots, who’re likely flying low in conflict zones.

Now imagine if you could convert your inventory of dumb weapons to smart, guided weapons with a simple plug and play component without any complicated mucking around with the rocket or integration with the aircraft.

BAE Systems has done just that, converting unguided 2.75 inch or 70 mm rockets into guided weapons, typically onboard attack helicopters, with a component that has a tongue-twisting acronym.

APKWS stands for Advanced Precision Kill Weapon System.

The Indian Air Force (IAF) is soon to place an order for AH-64D Apache attack helicopters and plans to order 32,000 unguided Hydra rockets to go with the aircraft, besides other elements. There are also plans to procure 82,000 unguided Belgian FZ-90 rockets for the Rudra, the armed Dhruv Advanced Light helicopter.

The APKWS module is compatible with both of these types and could convert them into guided smart rockets. In addition, the IAF has also issued a Request For Information (RFI) for rockets and guidance systems.

David Harrold, Director of Business Development of Precision Guidance Solutions at BAE Systems explained how it works at the Farnborough Air Show, earlier this year.

“The intent of the APKWS when it was originally developed was to fill the gap between unguided rockets with missions such as area suppression and marking – illumination and those kinds of things. And still we’ll have those kinds of missions. And larger anti armor types of missiles like Hellfire,” he said, adding, “The Hellfire missile is a very important missile for those anti-tank – anti-armor type of applications but may not be appropriate for softer, lightly armored targets and so we developed the APKWS to fill that gap.”

APKWS has a lot of things going for it, according to Harrold: “The beauty of the APKWS is the elegance of its simple design. All it really is, is a guidance kit that utilizes the existing warhead, existing fuze and existing rocket motor of a Hydra 70 which are pretty ubiquitous around the world.”

“It’s highly effective against those lightly armored and soft targets. Very low collateral damage because it uses the M151 warhead. There’s almost zero integration into the aircraft. It’s very simple to use. If you can shoot a Hydra, you can shoot an APKWS and requires no integration of the warhead, no integration of the rocket motor, no integration of the launcher and no integration to the platform, really.”

“It’s about a third of the cost of a Hellfire missile. It’s about a third of the weight of a Hellfire missile, as well. That’s important because it gives you more stowed kills, more on-station time, more ability to engage multiple targets than a larger missile might have.”

So how is it put together?

“It’s a mid-body design which is very different from most other seekers,” says Harrold. “This is the kit that, as you can see, screws in between the warhead and the rocket motor.”

“One of the major differences with our kit is really the DASALS (pronounced ‘dazzles’) – you see down there. The Distributed Aperture Semi Active Laser Seeker – that’s our technology. That’s our proprietary technology that underlies the success of APKWS. And really the innovation there is – traditionally seekers are nose-mounted. For laser-guided seekers they’re generally nose-mounted. What that means is you have a smaller quad-cell seeker on the front end of the rocket. We have this distributed aperture capability which gives you four different apertures and really gives you some major benefits.

If you have a nose-mounted seeker and all your optics are in the front, these things are packed in pretty tight in the launch tube. They’re right next to each other. In the back end of one of these rockets is a pretty violent exercise. There’s lots of flame and debris and smoke that come out of the back end there.

So a nose-mounted seeker is very vulnerable to damage from adjacent rocket fire. What that means is all that particulate that comes out the back end when one is fired has to go somewhere and if the optics are in the front end of the next rocket there’s opportunity to damage and degrade that. We don’t have that problem because our optics are held within the system and protected until they’re outside the launcher. That’s one benefit of the distributed aperture – of our innovation.

Second. Really important is that you’ve got this single nose-mounted seeker when it comes out its spending some time and energy looking for the target. It’s only got a small field of regard. We’re much different than that. They way we’re designed you have an instantaneous forty degree field of regard when we come out. What that translates to is very high accuracy. Much higher than any kind of nose-mounted seeker because if there’s laser energy out there reflecting off of a target we’re absolutely going to see it. So this is a very innovative way to address this problem and we’re the only ones out there that are not a nose-mounted seeker. So again, no changes. It’s really plug and play. We’ve done this with a number of different fuses, number of different warheads – no changes to the rocket, motor or tail fins or anything like that. It really is a very simple system.”

And how does it work?

“These seeker optics receive the laser energy from the target. Someone out there is designating the target with a laser designator. That laser energy is bouncing off the target and coming back, reflecting off. Our optics are picking up that laser energy that’s coming back up off the target. That’s the first piece of this. That’s really the start of this whole thing. There’s a laser designation on a target. Our optics open up and see that laser energy coming off that target.

The seeker electronics convert that laser energy to determine the target’s angle. Where they are. The inertial measurement unit sort of talks to where the rocket is – what’s the pitch, what’s the yaw, what’s the roll. Then the auto pilot uses those two different things. Where’s the target and where am I to really determine the flight path and these flaprons that come out here – there’s some control surfaces there that the control actuator system controls based on those two inputs.

That control actuation system moves those flaprons and commands the system to head towards the target. That’s the basics of how it works. Pretty simple.

Again, we talked a little bit about the forty degree field of regard that gives the pilot a very wide capability. A very easy capability to pick up a target pretty quickly and maximizes the probability of acquisition.

We’re not going to lose control of the missile. It’s going to stay in – if it loses the laser energy its going to stay headed in the same direction until it sees it again.

So notionally, a laser designator can come from the platform that’s going to fire APKWS, it can come from a different platform – say, a buddy helicopter that’s out there. or it can come from ground forces designating the target – if you have a forward observer or JTAC kind of personnel there.

So we need somebody to designate the target and APKWS is going to see it. That’s stationary targets, that’s moving targets, that’s on land, over the water – we’ve had very successful shots over water with moving boats. So the key to all that is just the laser being steady on the target.

So one of the benefits of that wide field of regard is an off-axis capability. The range of APKWS is 1.5 to 5 kilometers. Three kilometers is really the sweet spot for the weapons system. We talked about off-axis capability.

What this means is at three kilometers the pilots looking out of his cockpit. He doesn’t have to have the target here. The laser energy doesn’t have to be coming directly through the front side. The optics are good enough to have a fifteen degree off-axis capability. What that means is that energy is over here, that pilot can tickle it off and its going to see it and hit the target.

So it gives the pilot a little bit less stress because the pilot doesn’t have to be directly nose-on to the target.

Again, that is enabled by that distributed aperture capability.

There is nothing that the pilot can do to directly impact that rocket once it’s fired. One thing about the systems is that as it’s flying along, what it does is it goes into proportional navigation. What that means is if it sees the laser it’s going to lock onto the laser and it’s going to head for that laser reflection.

If that laser reflection goes away, its not going to then start looking all around. It’s going to continue to head where that was. Now interestingly, that has been very effective when we’ve done over water things. Now you can imagine in swells a designator can go back and forth. But our proportional navigation has allowed us to hit targets even though swells have come up and sort of taken the laser designator out of there. So it is designed – it’s not going to go anywhere else.

Once it’s fired, its going to head towards the last place it saw the laser designator and then in essence, it’s just going to act like an unguided rocket in that sense. It’s just going to head to where it was going.

The second piece of that is, there is an opportunity – if a pilot decided that where they were designated was not the place they wanted to fire you could pull the laser designation off of that target and then the rocket will stay with that laser designation. So if the pilot found ‘I launched it – that’s not where I want to go’, there is an opportunity to pull th laser off of the target and redirect. But the pilot has no direct connection or communication or data link or anything to the rocket once it’s been launched.”

Range and speed?

“So the distance is one and half to five kilometers- that’s the specification. Five kilometers is sort of the outside. But I will tell you that’s primarily driven by the capability of the rocket motor. Right, the rocket motor doesn’t have the juice to get it further than five kilometers, generally, from a helicopter hover.

There is some specification of speed of that moving target. But I will tell you we’ve done testing on lots of moving targets on land and over water and have never had an issue.

Notionally, you’re flying faster , you’re flying higher and one of the things that might come from that is further distance, but I will tell you that’s not a real – that’s not a deployed capability today so what we know is what we know.”

So how difficult is it to plug it in?

“From a logistics perspective it’s just like what we talked about with regard to putting it on the aircraft. No depot level maintenance, no unique equipment required.

It takes a strap wrench and somebody holding the other end tight and putting it together. This is no special equipment. This is literally for the Marine Corps – they get three pieces shipped to them – a warhead, APKWS and a rocket motor and the ordies – the ordnance men are putting it together in the field, putting it in the tube and they’re off to the mission. So it is very low maintenance, very low logistics requirement and so – it was intended to be that way, it was intended to leverage the existing logistics chain and to work very well anywhere where Hydra works.”

Who’s using it?

“Right now it’s the only government program of record for 70 mm in the US DoD. It was deployed in the United States Marine Corps in 2012 where it received its initial operating capability. We’ve had over 500 shots of APKWS and over 200 of those have been in combat with the United States Marine Corps. It was originally deployed with the Marines on the AH-1 Cobras and the UH-1s and we sell those through the United States Navy to the United States Marine Corps.

We’ve fired it off more than twelve platforms. Those include fixed wing and rotary wing.

We’re in full rate production. We’re currently in our third full rate production. We’ve recently delivered our 3,000th APKWS to the United States Navy. So very mature, technically, very successful in combat and just as importantly very mature from a manufacturing perspective.

Some of the milestones here:

It’s been deployed since 2012. We recently in 2013 had a successful airworthiness release on the US Apache. So we’re moving forward with trying to bring APKWS to the United States Army, as well as the Navy-Marine Corps. Again, as I said, we had the 3000th production recently.

In addition to having a mature manufacturing capability we also have capability to grow that production so we’ve got lots of capacity to increase without any major changes without any kind of brick and mortar changes we could increase from the rate that we are today threefold, just by adding a shift. So, we’ve really designed our manufacturing capability to be able to withstand additional requirements.

So we did this AWR for the US Apache which is a pretty significant milestone. Really impressive testing and qualification. Because of all of our previous firings both with the Marine Corps and others, we had minimal required shots. So we were able to leverage all those great things that we’ve done previously with APKWS to bring to the United States Army and minimize the number of shots that we needed to take in order to get that qualification which was pretty significant.

It’s going to be easily integrated into the Apache. There’s not going to be a problem there. So we’re really looking forward to bringing it to the army.

One of the important missions, especially within the navy is the fast attack craft, fast inshore attack craft threat, so the navy’s obviously concerned about that in some littoral water areas. So APKWS is going to fill that mission with the United States Navy. In fact the navy recently announced early operational capability of the APKWS in conjunction with their new digital rocket launcher. That’s going to bring to the MH-60 fleet a real capability that they haven’t had. So traditionally they had a seven-tube launcher for unguided rockets. Two of them. Now they’re going to have two nineteen tube launchers of APKWS. So you can imagine just the game-changer that that is.

They (US Navy) brought their Digital Rocket Launcher as a quick reaction capability or a quick program to the field. That Digital Rocket Launcher – the main purpose for the that is to enable APKWS. It’s on the MH-60 Sierras today, soon to be the Romeos – so that’s in the plan within the next twelve to eighteen months.

It’s been deployed to one squadron – Mh-60 Sierra squadron.

Having deployed it with the Marine Corps, now getting it into th navy inventory with the MH-60 fleet, indications are that the army is coming forward and will be bringing some APKWS to their inventory in the next year. These are all very good signs for us.”

What next?

“Additionally, last year we did a Joint Capabilities Technology Demonstration sponsored by CENTCOM with the United States Navy and the United States Air Force. That was to bring APKWS capability to fixed wing aircraft. We successfully fired a fixed wing variant off of A-10, F-16 and AV-8B. It’s a pretty big deal. We did the testing and some ironing-out development and then we did a military utilities assessment, it was just smashing. Really successful, really exciting for the customer. And now we’re in the process of figuring out what’s it going to take to bring that capability fully to those fleets.

As you may imagine sort of a hovering rotary wing situation from a lower elevation is much different from a high speed fast jet moving at high elevation situation. So there are some minor changes there but we’re continuing to look at what those minor changes would need to be in order to bring that to the fleet. And obviously if we could get the F-16, A-10 and AV-8, F/A-18 is a natural follow on. So we’re pretty excited about that. Not only domestically but also internationally.

Speaking of internationally, we just had our first international sale so earlier this year the Kingdom of Jordan purchased some APKWS from the United States Navy via the Foreign Military Sales process so we’re in the process now of working with the navy and figuring out how to deliver those to the Kingdom of Jordan. So that’s pretty exciting. They’re going to arm two CASA C-235 gunships that they’ve got there and we think there’s more capability that we could bring to the Jordanian armed forces with respect to the Cobra fleet and other places.

It’s currently obviously in the fleet for Cobra and Huey.

You can see here the FireScout – that’s the first UAV that we fired off of, very successfully. We’ve also had successful firings off of other aircraft as well. This is a very easy system to integrate onto any platform that already fires a Hydra 70. So that’s why its been relatively painless to go down this path of multiple platforms.

In addition we have potentially some more platforms. You see the Hawk outside – we’d like to put the APKWS on that – the army Blackhawk – that’s on the horizon. I mentioned the F/A-18 Hornet as part of an objective for the JCTR fixed wing variant and the 235 gunship, of course, that’s as we discussed with Jordan.

About a five and a half million dollar contract (Jordan) and that includes both the guidance sections that they purchase plus some level of support.”

Would APKWS be compatible with other rockets?

“There’s tons of Hydras. Hydras are pretty ubiquitous not just in the US but around the world.

Literally if there’s another 70 mm rocket I know it’ll screw together, right? What I don’t know is will that work as well as the Hydra 70. So we are going down the path of – we’re always looking at those options both for additional rocket motors and warheads and launchers and platforms so that’s all within our roadmap of testing other rocket motors and other warheads to see if they’re working.”