AIM-120 AMRAAM projects

[TinWing]

Does anyone have an information of the Hughes Asam-1, an AMRAAM derivative that was offered for the UK's cancelled MSAM requirement. 

The Asam-1 featured an enlarged diameter solid rocket motor and reached the flight testing stage in 1992. 

[sferrin]

Does anyone have an information of the Hughes Asam-1, an AMRAAM derivative that was offered for the UK's cancelled MSAM requirement. 

The Asam-1 featured an enlarged diameter solid rocket motor and reached the flight testing stage in 1992. 

And here I thought I was losing my mind.  I'd read about that back then and wondered what ever happened to it and then along comes ESSM and I thought "I could have sworn it was AMRAAM they'd made with a bigger motor and land launched".  Anyway here's a link to a video that was recently posted in the ejection seat thread on the Key Publishing forum.  The first part of the video is about thrust vector control of a land launched AMRAAM.  The interesting part (to me anyway) is that unlike ESSM it appears to have TVC until burnout.  Also note that the motor appears to pulse on and off during cruise just before it snaps up there at the end.

[PaulMM (Overscan)]

Hughes, later Raytheon, proposed an airbreathing AMRAAM derivative for the European FMRAAM requirement.

[TinWing]

Finally, a close-up picture of the ASAM-1 and definitive proof that it had a 10-inch diameter motor.

http://forum.keypublishing.co.uk/showthread.php?p=1077692#post1077692

It is hardly a mystery why the program didn't proceed.  The UK effectively cancelled its MSAM requirment.  Without the UK as a potential launch customer, this intermediate capability missile didn't fit very easily into the post-Cold War market.  It is easy to sell a high end system with tactical ABM capabilities, such as Patriot, or a smaller missile in the MANPADS or VSHORAD segment such as Stinger/Mistral, but there have been few opportunities for land based systems that fall between the two extremes of capability.

[PaulMM (Overscan)]

Raytheon's AMRAAM design

via http://www.dodmedia.osd.mil

[Pyrrhic victory]

Here are a few of pictures of the Raytheon AMRAAM mock-up found at the back of the F-15A section of www.defenseimagery.mil
Interestingly, an adapter was used on the semi-conformal AIM-7 wells on the F-15.

Location: EGLIN AIR FORCE BASE
Date Shot: 3/13/1981

[Colonial-Marine]

I hadn't seen a topic for AIM-120 AMRAAM related projects so I figured I would start one here. There are a few designs I am curious about.

Back in the 80s/90s, Raytheon I believed offered the FMRAAM in a European competition that would end with the MBDA Meteor being selected as the winner. IIRC it was similar to the Meteor in that it used a ramjet to provide greater range and maneuverability. Was the FMRAAM developed any further? Since then Raytheon has offered the ERAAM and ERAAM+ which use a dual-pulse motor and are designed to be compatible with future propellants and technologies. What is the current status of these projects.

The AIM-120D is scheduled to enter service soon, and is said to offer a 50% increase in range among other things. Yet apparently a dual-pulse motor is not used? What has been changed or modified over the C5 motor to enable this?

Finally, not too long ago I saw a photo of what looked like an AMRAAM with a single relatively compact ramjet between the fins as opposed to the two featured on the FMRAAM and Meteor.


A press release from October 2009 gives some hints of potential further development to the AMRAAM family.

ATK Currently Supplies Propulsion Systems for All U.S. Fielded Air-to-Air Missiles
Technologies Developed will Position ATK to be the Propulsion Supplier of Choice for Counter-Air and Counter-Air Defense Missiles Developed for U.S. Services

Oct 29, 2009

MINNEAPOLIS, Oct. 29 /PRNewswire-FirstCall/ -- Alliant Techsystems (NYSE: ATK) has been awarded a research and development contract for the Counter Air / Future Naval Capabilities (CA/FNC) program to develop technologies that can be incorporated into next generation air-to-air missile systems. The nearly $10-million contract was issued by the Naval Air Warfare Center Weapons Division, China Lake, California. ATK will work in concert with NAWCWD to identify specific propulsion technologies to develop for integration into future missile systems. The work is expected to be completed by June 2013.

The scope of the CA/FNC program is to develop technologies that will extend missile range, decrease time-to-target, improve end-game maneuverability, and improve the rocket motor's response to insensitive munitions (IM) stimuli. These improvements are oriented towards the 7-inch diameter Advanced Medium Range Air-to-Air Missile (AMRAAM) that is currently in use by the U.S. Navy, U.S. Air Force, and many allied nations, but will be applicable to other air-to-air missile systems.

There are four main areas that ATK will be concentrating their development efforts on which include: high burn rate propellants for improved kinematics; improving case stiffness for reduced weight and agility; low erosion nozzles for improved performance; and multi-pulse propulsion for end-game maneuverability. Additionally, ATK will address the IM requirement by incorporating affordable solutions including an advanced propellant formulation, a low cost composite case, and mitigation safety devices proven on other tactical rocket motor programs.

http://atk.mediaroom.com/index.php?s=118&item=970

[AeroFranz]

Raytheon's NCADE is being pitched as a ballistic missile intercept variant of the -120, featuring parts of the -9X sensor, new motor by Aerojet

more information here:

-http://www.raytheon.com/newsroom/rtnwcm/groups/rms/documents/content/rtn_rms_ncade_07-09_datasheet.pdf (company brochure)
-http://www.flightglobal.com/articles/2009/06/04/327420/raytheons-ncade-survives-fy10-budget-cuts.html

[Colonial-Marine]

Have any details been released about any upgrades the AIM-120D had to it's motor or propellant in order to gain the increased range?

[sferrin]

Have any details been released about any upgrades the AIM-120D had to it's motor or propellant in order to gain the increased range?

AvWeek said it has a dual-pulse motor but there seems to be some dispute there.

[SpudmanWP]

The Aim-120D DOES NOT have a Dual Pulse motor.

1.  ATK, the ONLY current maker of AMRAAM motors states that they only make two types of motors, the baseline and the PEP (extra 5 inches) motor introduced in the C5 model.

http://www.atk.com/capabilities_defense/cs_ms_w_trm_aam.asp

2.  Here is the PEP doc

http://www.atk.com/datasheet_PDFs/AMRAAM.pdf

3.  ATK just got (Oct 2009) a contract to develop the next generation of AMRAAM motor.  One of the technologies they are researching is a dual pulse design.  If it were already in the 120D, they would not have to develop it again.

http://atk.mediaroom.com/index.php?s=118&item=970

I think where everyone gets the idea of the 120D having dual pulse is that the AMRAAM currently has a dual propellant motor.  All AMRAAM motors have a "boost/sustain" grain type which may be the cause of the confusion.

[Colonial-Marine]

Alright, here is that picture of that AIM-120 variant I was looking for.



What is it? And is it in a janitor's closet or something (judging from the guy in back)?

Now would there be any benefit to designing a missile with a dual-pulse motor and ramjet or do they fulfill the same role?

[SpudmanWP]

They perform different roles.  A dual-Pulse motor will boost, from outside the targets MLD detection range, the AAM in a high arching profile.  In mid-flight the first pulse (think first stage that does not jettison) cuts out and the AAM coasts until it is well past it's apogee.  When the AAM is well into it's downward arch, it's 2nd pulse ignites when it is relatively close to the target.  This ensures that the AAM is gaining energy in the end-game and can take advantage of TVC if it has it.

A ramjet AAM just has a longer burn and never turns off until it runs out of fuel.

One benefit of Dual-Pulse is that the AAM can "sneak" up on a target as it's motor is off until it is very close.

As to what that missile is, best I can come up with is a VFDR testbed.

http://www.strategypage.com/militaryforums/6-52704.aspx

[sferrin]

All AMRAAM motors have a "boost/sustain" grain type which may be the cause of the confusion.

No, the confusion comes from AvWeek saying it had a dual-pulse motor (like SRAM).  Everybody and their dog knows what boost-sustain grain profile is.  The new PAC-3 MSE also has a dual-pulse motor.

[SpudmanWP]

Then someone at AvWeek needs to be slapped for not doing their research.