Chaparral

[pathology_doc]

Why, if they were concerned about head-on attacks, did they not do the obvious and use AIM-9C as a basis for this? And how hard would it have been to transplant the Crusader's radar and FCS onto the ships? Sure I know Sparrow is by far the better vehicle - but if you're fitting what basically amounts to RIM-9 because of weight restrictions anyway, why not take the SARH option?

I'm sure anyone who knows the technical ins and outs of radar-guided missiles in general and AIM-9C in particular can fill me in, but please don't tell me nobody ever thought of it...

 

[Sea Skimmer]

Semi active radar would have cost a lot more and suffered from ground clutter. That's pretty much it; and the reason why Chaparral lasted so long with no replacement, simply no money for it. The inability to hit a target head on is not as great a disadvantage as it might be when numerous mutually supporting Chaparral fire units protected by 20mm Vulcans are deployed around a defended locality as was intended. Also because of the location of the engine exhausts on the sides, it was possible to hit many 60s and 70s battlefield helicopters head on even with the limited Sidewinder technology.

The Soviets deployed the similar capability SA-9 system around the same time; but they spent more money on air defense and replaced it with SA-13 from 1979 onward which did have a limited head on capability. So really Chaparral was only outdated in comparison for about ten years of lifespan, followed by a quick post cold war draw down. The US had intended to use Roland to provide a modernforward radar directed battlefield missile system with more protection then SP HAWK, but that project fell apart repeatedly.

 

[pathology_doc]

I'm sorry I didn't make my original post clearer - I was considering the shipborne variant. Wouldn't this make the clutter problem slightly less awful (because the "terrain" is a lot flatter and most of your firing is basically upwards, unless your launcher is WAY above the water)?

Cost a lot more? But given that the F-8 Crusader existed at the time and was fitted for SARH AIM-9C, don't you have all the development (missile, launcher, matched illuminator/FCS) as off the shelf components, done, and just requiring duplication, with all the economy of scale this entails? Or is the conversion to surface fitting still a godawful problem?

 

[TomS]

The nice thing about IR Chaparral is that it was almost entirely self-contained, which suited its basically stop-gap nature. Adding a radar illuminator would have made it a more elaborate installation. But the Navy, of course, had other plans for its long-term point-defense solution -- including the SARH Sea Sparrow.

 

[Sea Skimmer]

Sorry I didn’t realize you meant the sea version only; that lasted what, barely one year in USN service? So the navy had no reason to care if it worked at all. Most of the mounts which were built were never mounted on a US warship.

BPDMS was going to be way better then AIM-9C could ever be and had enough warhead to actually be sure of killing what it hit. Normal Chaparral meanwhile isn’t just almost entirely self contained except power, almost everything is self contained to the actual Sidewinder missile on the rail. All the operator and mount does is trigger arm-uncage seeker-launch. That’s pretty nice for a stop gap.

Anything with radar will have to be a more expensive, major electronics units are being added to the equation. Plus if want to adapt aircraft systems to a ship you now need to design a director to hold the radar, and a slave circuit to make the launcher follow the radar movements. Then that has to be tested.

The navy didn’t just copy the aircraft radar gear to make Sparrow work as BPDMS so I think they probably had a reason to go design new illuminator only radar. Basically anything that is developmental at all makes no sense as I do believe BPDMS was available just about the same time as Sea Chaparral.

 

[pathology_doc]

Aha. That explains things very nicely, then. Thank you.