AMRAAM-ER

Moose

ACCESS: Top Secret
Senior Member
Joined
Jul 4, 2010
Messages
1,564
Reaction score
694
"Sidekick"? Is that some fanboi lingo? Also, there's nothing official about size. Just a bunch of blogger speculation.
Sidekick is the weapons bay adapter for the F-35A/C that allows them to carry up to 6x AMRAAMs internally; I personally haven't heard any confirmation that JATM will fit Sidekick, but it would be unfortunate if it couldn't.
Short of a multistage missile (say a boosted CUDA) I don't see how they could get a significantly greater range than AIM-120D in the same envelope. I got the impression that AIM-260 is something larger.
Stretch the fins out into strakes and range will jump. If they're using divert thrusters for terminal maneuvers, like on CUDA, the aerodynamic package can be tailored to range rather than agility.

Could you enlarge the fuselage diameter if you didn't need fins at all? Or had tightly folding ones? Even the cropped fins in AIM-120D take up some box space.
Most likely, though it would be better to give it some kind of lift-generating shape rather than just a cylinder. There's also the RAM Block II approach of increasing the diameter of the fuselage between the fore and aft fins.
 

TomS

ACCESS: Top Secret
Senior Member
Joined
Apr 16, 2008
Messages
4,989
Reaction score
2,578

NMaude

ACCESS: Secret
Joined
Mar 12, 2021
Messages
276
Reaction score
232
I believe I have discovered the guidance-law used by the AIM-120:

Proportional Guidance (PROGUIDE) and Augmented Proportional Guidance (Augmented PROGUIDE)​

Abstract​

Two new homing guidance laws, designated as proportional Guidance (PROGUIDE) and Augmented Proportional Guidance (Augmented PROGUIDE), have been developed for use against non-maneuvering and maneuvering targets, respectively. These guidance laws are the solutions of linear-quadratic regulator control problems and minimize deviations from the collision triangle over the entire period of homing flight, thereby indirectly minimizing miss distance. In contrast to proportional navigation (PRONAV), these algorithms command the achievement of angular acceleration instead of linear acceleration and there is a significant advantage in doing so. The guidance laws (1) are more compatible with the seeker measurements which are angular in nature, (2) do not require an estimate of time-to-go, (3) can be used to directly drive the skid-to-turn or bank-to-turn logic that produces autopilot input commands, (4) avoid actuator saturation through the real-time adjustment of a single parameter in each channel, and (5) are less sensitive to random errors. Thus these guidance laws are not only effective in and of themselves, but also provide a simple framework within which an integrated guidance and control design can be carried out. The integrated design accounts for interactions between the target state estimator, the guidance law, and the autopilot during the design process.
Why do I think it's this particular guidance-law?
A) A direct reference to the AMRAAM programme office is made in it.
B) The equation doesn't have a time-to-go component in it due to the way it was derived which is important as the Tgo value is usually an imprecise calculated value.
 

sferrin

ACCESS: USAP
Senior Member
Joined
Jun 3, 2011
Messages
14,745
Reaction score
3,720
"Sidekick"? Is that some fanboi lingo? Also, there's nothing official about size. Just a bunch of blogger speculation.
Sidekick is the weapons bay adapter for the F-35A/C that allows them to carry up to 6x AMRAAMs internally; I personally haven't heard any confirmation that JATM will fit Sidekick, but it would be unfortunate if it couldn't.
Short of a multistage missile (say a boosted CUDA) I don't see how they could get a significantly greater range than AIM-120D in the same envelope. I got the impression that AIM-260 is something larger.
Stretch the fins out into strakes and range will jump. If they're using divert thrusters for terminal maneuvers, like on CUDA, the aerodynamic package can be tailored to range rather than agility.

Could you enlarge the fuselage diameter if you didn't need fins at all? Or had tightly folding ones? Even the cropped fins in AIM-120D take up some box space.
10" booster. and folding fins (Basically ESSM with everything forward of the motor closure replaced:

1621908070472.png
 

Dragon029

ACCESS: Top Secret
Joined
Mar 17, 2009
Messages
866
Reaction score
356
Only thing you've gotta watch out for is the overlap geometry - based on the fact that the F-35B isn't getting Sidekick, and 2x AMRAAMs and an adapter shouldn't exceed anywhere near 1500lb, the logical conclusion is that the F-35B's truncated bays (where they're shorter in length) would be prohibiting AMRAAMs from being staggered fore / aft like how the F-22 carries 6x AMRAAMs in its main bay.

So even if (eg) a 10" rocket body doesn't exceed the wingspan of an AIM-120D, it might still not fit with Sidekick as you might have fins of each missile overlapping with the body of another, rather than just having fins overlapping fins.
 

bring_it_on

I really should change my personal text
Joined
Jul 4, 2013
Messages
2,674
Reaction score
1,025
The entire air to air missile "portfolio" resides with one company and the last thing they would want to do is hand it over to another. You've got to have multiple OEM's producing competitive prototypes that add value at one level or another. It sounds like this is what they are looking to do. Seems like pursuing the AIM-260, something in the "HALFRAAM" class (cheaper, smaller/larger-mag) and a Very long range AAM are all areas to put some money in and keep the 2-3 design teams busy over the next decade.
 

GTX

All hail the God of Frustration!!!
Staff member
Senior Member
Joined
Apr 15, 2006
Messages
3,846
Reaction score
2,399
Website
beyondthesprues.com

Scar

ACCESS: Confidential
Joined
Apr 25, 2019
Messages
187
Reaction score
390

NMaude

ACCESS: Secret
Joined
Mar 12, 2021
Messages
276
Reaction score
232
it's essentially a variant of the Russian 9M96 missile used in the S-400 system:
So a South Korean version of the SA-21 Growler.
Korean SAM is a cousine of S-350 Vityaz.

So still a variation of the SA-21 Growler missile.
 

Scar

ACCESS: Confidential
Joined
Apr 25, 2019
Messages
187
Reaction score
390
So still a variation of the SA-21 Growler missile.
S-400 premier missiles are long-range 48N6-family and 40N6, while mid-range 9M96 is a cross-platform missile, that can be used with S-300PM2, S-350, S-400 and naval Redut ADS.
 
Top