Indirect Airborne Rocket Artillery
In his letter on Artillery re-supply problems (www.G2mil.com March 2001), Mark Gallmeier wrote
.We can't afford the extravagance of keeping 6 tubes per FA battalion hanging around waiting for a moment that may never arrive. And when that moment does arrive the ammunition probably won't be available anyway.
One idea I've dabbled with is developing an unguided rocket (10-15km) for UH-60 Blackhawks to haul up and fire in volley from masked positions. With GPS to locate and computers to calculate firing data the accuracy will be pretty good. The beauty of this is the firing platform easily returns to the rearm/refuel point. Now that we're out of enemy artillery range we can site the rearm/refuel point for easy supply truck access
..With counter-battery where it's at today shoot n scoot is already SOP. Rotors scoot better than tracks or wheels. "
These comments also remind me of a passage in Kenneth Macksey's excellent book "Tank Warfare" :-
"By subsituting dive bombers for heavy artillery the Germans had relieved themselves of the administrative problem of moving and supplying a seige train.."
These comments should be balanced by this passage from Maj-Gen. Julian Thompson's "War behind Enemy Lines" (Page183):-
"Artillery fire can be adjusted on to the target by the observer, talking over the radio to the gun position, and it matters not if the first rounds miss. Once a complete air strike sortie has delivered its ordinance, missed and pulled away, even observed strikes cannot be adjusted. Also artillery fire, if available, is on tap whatever the weather, day or night."
These comments were made about World War 2 fixed wing aircraft with unguided ordinance. While some of these comments will apply to helicopter fired rockets, I can see no reason why a hovering helicopter can't fire single rockets and adjust its aim.
Airborne Rocket Artillery (ARA) was used in Vietnam, although these were mainly used for direct fire missions using the 2.75" Hydra FFAR. Mr Gallmeier's idea involves using a larger rocket capable of indirect fire.
Since we are discussing a rocket for indirect fire such a helicopter would not be visible to the target. A helicopter launched indirect fire rocket probably can't be fired at steep elevations but range may also be varied by adjusting launch platform altitude and possibly rocket burn time. A helicopter can also adjust its fire by moving nearer or further from the target with much greater ease than can a land vehicle
It is also possibly worth pointing out that helicopter based artillery would have a far greater choice of firing positions - for example, from over swampland or open bodies of water.
Counter-battery radar may have problems with estimating the fire position of projectiles that do not start at ground level, so counter-bombardment may often overshoot the firing position. This may need to be considered if operating near friendly forces or population centres.
For such a rocket to be effective it will need the following characteristics:-
Four possible types of rocket suggest themselves:-
- It should be capable of being launched from a helicopter (pretty obvious that!).
- Destructive power at least equal to a 155mm shell would be preferable. This is widely quoted as the minimum size of projectile suitable for breaking up massed armour.A typical 155mm shell has an explosive content of 15lb (6.8kg).
- A range of at least 10km and the capability to fly indirect-fire trajectories.
If possible rockets shoudl be handled and shipped in four-shot 2x2 "launch-cases" (with the possible exception of the M26/28). Even a very small helicopter could carry one of these and larger aircraft could carry multiples. This would allow mixtures of different types of round to be carried and allow faster replenishment when only part of the load has been fired.
- A modified Hellfire missile. This is already helicopter compatible and has a range of c18km. (The range of the Hellfire is often given as being less than this figure. The 3,750m range most widely publicised was in fact Cold War misinformation and many sources have not been updated). An "Artillery Hellfire" that can fly a ballistic course, possibly with an inertial system to counter factors such as wind-drift could be created. An inertial guidance system along these lines is used for the Predator ATW. Swedish Hellfire Shore Defence System (HSDS) uses a 9kg HE blast/frag warhead.
- A two-part rocket using a simplified 155mm shell as the warhead. Facilities to mass-produce these already exist and a wide range of ammo types already developed. Unnecessary features such as the driving band can be eliminated, simplifying production further. For certain fire missions the rocket might use retarding systems such as air-brakes or ballutes to alter its trajectory. 160mm rockets such as the IMI LAR and FAMAE/RO Reyo might also be suitable for indirect ARA applications. Weight of a single rocket is 100-122kg.
- A shortened version of the M26 MLRS, having the same warhead but a smaller rocket motor for a range of 10-15km instead of 40km. (Credit due to Carlton Meyer for thinking of this one). Possibly the M28A1 Practice rocket could be adapted to this role. The ground launched M26 owes much of its range to the fact that it is launched at a high elevation. Fired at a near horizontal attitude it may have a performance suitable for Indirect ARA. If this proves the case means should be found for the standard 2x3 Shipping/Launch Rocket Pod Container (RPC) to be installed on helicopter pylons.
Possible problem with using the M26 is that each rocket weighs 306kg and a Rocket Pod Container 2,308kg which may be too heavy for many helicopters.
- An air-launched version of the EFOG-M. Since the EFOG is based on the TOW is should be helicopter launchable. This may be slower than the other weapons suggested but less rounds would be needed since the projectile can be guided straight onto the target.
- A combination of all of the above systems.
The posibility also exists that any available helicopter with weapon pylons could be pressed into service to launch Indirect ARA rockets although the aircraft leading the Flight-battery would need software to calculate rocket trajectory for the given target co-ordinates. This is not a major obstacle since handheld ballistic computers have been available for some time. The lead aircraft would fire ranging shots then inform the other craft of the correct elevation/altitude once an observer confirmed that rounds were on target.
Ironically, I can also see several ground fired applications for such rockets.
- An AFV or Truck mounting several launch cases may supplement or substitute for tube artillery. An accompanying cargo vehicle with a mechanical arm could quickly replace fired launch-cases, giving a fairly sustained rate of bombardment.
- Launch-cases could be positioned on the ground and fired by remote command at pre-determined co-ordinates. Counter-battery fire would just destroy the empty launch-cases. In this application a small force observing a MSR could have its own organic artillery support.
A friend of mine is very fond of military applications for trailers. A launch case-mounting trailer could contain remotely controlled elevation and traversing mechanisms.
- A single shot launch-case might be developed for SOF/Guerrilla use.
- Front line vehicles such as MBTs and IFVs could mount launch cases that are fired at a position as an immediate prelude to an assault.
Following the January 2002 edition of G2mil, Bill Clarke writes:-
"Frankly, I'd rather see an A-10 overhead....
You can have that too. Since I've began writing in this field one thing I notice is the "Either-Or" mentality. If you suggest anything new it is automatically assumed that this means getting rid of something else -that's not directed against you in particular, just an interesting observation. Another observation is that an A-10 would be easier to shoot down by the forces being attacked than a rocket carrier hovering a few feet above the ground over the horizon. Interesting that most OPFOR deploy far more numerous and varied AA systems than we do.
I wasn't able to contribute directly to this month's G2mil, so the article you see there is an abridged version of a bigger one written by the editor. The full version can be read above and this should make some points clearer. It includes some discussion of air attacks instead of indirect barrage.
The AGM-114 Hellfire idea isn't bad though. I think making it dumb would be. I would remove the laser seeker and replace it with a cheap (about $75.00) GPS receiver. I would also use a less powerful (read that cheaper) rocket motor- Mach 1 speed is not necessary for such an application (about mach .5 would be plenty). Last, a simple 20lb (the size already carried by the HF) blast/fragmentation variable-fused warhead for dealing with troop concentrations.
I like the idea of the GPS system-though obviously some investigation should be made of the accuracy of the "dumb version" I don't think my original article mentioned that the hellfire should be unguided -I did mention EFOG-M for indirect fire -and of course, standard hellfires can be used for indirect fire if there is a ground laser to illuminate the target
I see no need for an expensive second stage, as the launching chopper could just fire the munition from an altitude of a few thousand feet on a ballistic trajectory. This would yield a range of around 10 miles.
The second stage is only for the 155mm shell based rocket -to adapt it to rocket propulsion (there are precedents to this such as the "Land Mattress" system that mated a 5" naval shell with a 3" Surface to Air rocket). Having the warhead detach to "drop short" was a suggestion to increase versatility, and reduce minimum range.
Tube artillery (which this system would augment/replace) is pretty well useless against modern armor, so I would leave that to TACAIR, Army Aviation and MLRS systems.
Obviously this would depend on the warhead type -this is a form of MLRS system, after all
Just to set the record straight, I do think the idea has a good deal of merit. A C-17 deployable Blackhawk based air artillery system would definitely add a whole lot flexibility to a mechanized task force. The main reason I brought up the Hellfire was due to my feeling that it could accomplish all of the needs of the mission you laid out, as opposed to designing something new. If anti-armor is needed, then the original 20lb Shaped charge would be fine. For APERS a simple GPS guided, prox fused- blast/frag would be quite lethal. The GPS system could include an altimeter or a simple laser proximity system for air-burst.
As far as the A-10 comment, I WOULD rather see an A-10 overhead than any other type of support I could have. (except for a direct line to an Iowa class BB offshore!)
I like the idea of the Hellfire for one simple reason. The US Army would be a whole lot more willing to make minor modifications to an existing system than to design a whole new system based around a 155mm or MLRS. They may be better for the job, but the Hellfire GPS rockets would be a lot easier to sell. Lockheed has already developed a blast/frag warhead for it, GPS receivers are a dime a dozen, and the Hellfire is still in production. The ESSS system for Blackhawks is already compatible with Hellfires. It would take very little effort to make this plan work if it was based on the Hellfire. It could be in service in a matter of months.
In my experience, artillery or mortars were almost always available, but in the real world their (tube based) anti-armor capabilities are extremely limited. The MLRS is another story. Anything that can add to the firepower of friendly forces is welcome by me.