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Now that the ASRAAM has been improved, and is a competent AAM with a wide variety of capabilities. Will the US purchase them for use on their own F-35s and other aircraft along-side the AIM-9X?

While the AIM-9X has demonstrated LOAL and internal bay use is possible (for the F-35.), owning a bunch of ASRAAMs just to gauge capability and to buy an item from our allies would be a good idea overall.

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Elite Joined: Oct 21, 2005 Posts: 757 Status: Offline

While I think it too would be a good idea, don't count on it.

Elite Joined: Aug 02, 2006 Posts: 942 Status: Offline

I don't think making a service order of the ASRAAM is needed to gauge its capability. Its capability was gaugs extensively and was found lacking. It was also supposed to have been ready in ~1985 just ahead of the AMRAAM, but it was 15 years late. That was why the AIM-9X was developed. There is essentially no advantages to the ASRAAM other than the fact that it has a slightly newer and better motor. The AIM-9X uses the AIM-9M motor pretty much unchanged.

Elite Joined: Jun 29, 2005 Posts: 781 Status: Offline

The asraam is an awesome wvr missile working on a different principal to the 9x and iris-t (speed instead of manouveurability)... it may be useful to test a weapon with a full sphere engagement envelope (unlike the 9x's) however I doubt it will happen.

The US pulled out of the Asraam when they weren't getting what they wanted (a low budget sidewinder supplement). After that the British had the choice of cancelling and joining the 9x program or going it alone, which for a change they did and threw money by the bucket load at the missile to make (arguably) the best wvr missile at the time.

It would be the same position if the US purchased Asraam, they would be acknowledging they were wrong to pull-out or restrict the project which the media would pick up on.

I'm eagerly awaiting the news that is due soon if we are going to upgrade our Asraams to P3I standard. An upgrade that includes 3d tvc being included in the missile.

Andy

Elite Joined: Jul 22, 2005 Posts: 965 Status: Offline

I'd swear I read recently that the -9X is getting a new motor but don't quote me on that.

I see no plans for the US to buy ASRAAM. They have the JDRADM programme underway (which recognizes that AIM-9X is not up for the job). Also the 'not invented in the USA’ principal would also kick in. The main differences of approach is that the US wanted an improved Sidewinder that would win in post merge combat - in other words, good turn performance for post merge dog fights. The UK (and Australia!) wanted a weapon with the best No Escape Zone possible thus avoiding the merge wherever possible. ASRAAM may sacrifice ultimate short-range turn performance but with its significantly larger rocket motor (AIM-9 has 5" motor, ASRAAM has a 6.5" motor according to Jane's) but will out shoot anything out there. Add Lock-after-Launch to give you a 360-degree capability (linked with F-35's sensor fusion) and you have a winning combination. No news of adding TVC to ASRAAM. TVC adds weight, gives you nothing at the end game but you never know what the UK and Australia might have planned for the future. I know which weapon I'd want on my aircraft as I’m not really sure where 9X can win in a dog fight, especially as AA-11 has longer range.

Elite Joined: Aug 02, 2006 Posts: 942 Status: Offline

Quote:

...Add Lock-after-Launch to give you a 360-degree capability (linked with F-35's sensor fusion) and you have a winning combination. No news of adding TVC to ASRAAM. TVC adds weight, gives you nothing at the end game but you never know what the UK and Australia might have planned for the future. I know which weapon I'd want on my aircraft as I’m not really sure where 9X can win in a dog fight, especially as AA-11 has longer range.

The AIM-9X has Lock-on-after-launch capability as well from day one. You can pop an AIM-9X at a target its seeker head cannot "see" prior to launch -- such as targets obstructed by the airframe or in the rear hemisphere -- despite its >180 degree seeker envelope.

The biggest difference between an AIM-9X and the ASRAAM is that the AIM-9X has better off-boresight engagement capability -- shooting to the side and backwards for instance -- because of its ability to pull sharper turns immediately post launch. The AIM-9X is also better optimised for high offset tracking of the target in lock-on-before launch mode. In short, the AIM-9X is the better dogfight missile. The ASRAAM is kinematically the superior missile. I In fact, the ASRAAM is kinematically very similar to the MICA (they both have a 6.3~6.7 diameters, similar fuel fractions and similar HTPB propellant). Like the MICA, the ASRAAM is a short-medium range WVR/BVR AAM with an effective range in access of 50km. The ASRAAM is also almost as fast as an AMRAAM (Mach 3.5~4 on high energy launches vs Mach ~4.5 for the latest AMRAAMs). The ASRAAM however is not equipped with thrust vectoring or pitch change enhancing surfaces, so it is a decidedly less capable missile in a pitch fight.

The reason the USAF/USN is not particularly pleased with the ASRAAM is that the USAF/USN wanted the best dogfight missile it could get for short range, high off-boresight launches. Currently, and in the foreseeable future the US aircrafts are NOT going to even try to meet or exceed the agility of foreign designs due to priorities such as stealth. So an extremely capable high-off boresight WVR AAM is seen as a nice complement to US fighter doctrines. As far as extended range performance, the USAF/USN is more than happy to dedicate that to the 100+ km AMRAAM C7/Ds which significantly exceeds the performance of 6"/250lbs class missiles like ASRAAM or MICA. In fact, in many recent deployments (with the AIM-9M being the mainstay WVR AAM) US jets frequently just use the AMRAAM for WVR combat anyway as the AMRAAM has proven itself to be quite capable even as a WVR missile thanks to its excellent seeker, superb energy content and lock-on-after launch bore sight capability.

[quote="dwightlooi"]

Quote:

Currently, and in the foreseeable future the US aircrafts are NOT going to even try to meet or exceed the agility of foreign designs due to priorities such as stealth.

I would have to argue that the F-22 and perhaps the F/A-18E/F (not to sure about the F-35, though I believe this jet will surprise us) can hold their own in the maneuverability department. One of those two can definitely meet and exceed (to some degreed) the agility of most, if not all, foreign aircraft. However in general your point is still valid, most US designs, now, and in the near future, are not centered around uber maneuverability above all else. But rather "good" maneuverability with greater emphasis on BVR and outstanding SA.

Also, I believe stealth technology has matured to a level where you no longer have to sacrifice all maneuverability for stealth, as the F-22 and F-35 have shown.

Elite Joined: Jun 29, 2005 Posts: 781 Status: Offline

dwightlooi wrote:

The biggest difference between an AIM-9X and the ASRAAM is that the AIM-9X has better off-boresight engagement capability -- shooting to the side and backwards for instance -- because of its ability to pull sharper turns immediately post launch.

The Aim-9X has better terminal manouveurability not immediate launch; that is an area where asraam is better. Its the reason why it has a full sphere engagement envelope as it can pull a full 180 as it actually leaves the rail!

Andy

Thanks Dwightlooi for the good reply. I wasn’t aware that 9X has Lock-on-after-launch at all. Thought the US forces preferred lock before launch only!

I agree with your point about the better short-range performance. 9X can pull sharper turns immediately post launch for sure. The issue is whether the motor performance from the 5” Sidewinder motor can produce enough thrust to both turn the missile tightly and then chase the target. Something I suspect that ASRAAM can do as the larger rocket motor would produce significantly higher thrust. Also with 9X, once the motor has burnt out the TVC isn’t working and pitch-enhancing surfaces just add to drag and therefore slow the missile down. At the end game missile kinematics must surely give you the added agility you need to hit the target.

I don’t really see such similarities between Mica and ASRAAM though (apart from rocket motor size). Mica (according to Janes) is much heavier and has a lot of wings and fins – so looks pretty draggy to me.

I have to agree with you that the emphasis is different. The US seems to me to be moving more towards stealth than manoeuvrability. I think that this is supported by the fact that the US wanted a dogfight missile and the UK and Australia wanted a weapon to dominate WVR combat. I guess it shows the differences in nation’s concept of operations, 9X must certainly be the ultimate in close-in dog fights whereas ASRAAM probably has the better no escape zone – it depends what you are looking for.

I also agree with you about AMRAAM meeting the current needs, although I think in recent conflicts AMRAAMs were used instead of 9M due to the limited CM performance of Sidewinder. AMRAAM would have a much better chance of hitting the target. For the future, and with reports of Ram Jet powered AA-12 etc being developed, I think it doubtful whether AMRAAM can keep up with the fight. Then I guess that’s why Europe is developing the Meteor missile. I presume the ‘mach 4.5 AMRAAM’ was a misprint.

Elite Joined: Aug 02, 2006 Posts: 942 Status: Offline

Tintin wrote:

I also agree with you about AMRAAM meeting the current needs, although I think in recent conflicts AMRAAMs were used instead of 9M due to the limited CM performance of Sidewinder. AMRAAM would have a much better chance of hitting the target. For the future, and with reports of Ram Jet powered AA-12 etc being developed, I think it doubtful whether AMRAAM can keep up with the fight. Then I guess that’s why Europe is developing the Meteor missile. I presume the ‘mach 4.5 AMRAAM’ was a misprint.

The maximum speed and range achieved by an AAM depends heavily on the speed and alitude at which it is launched. It also depends on the flight profile -- whether the missile will be diving on the target or climbing up to it. The AMRAAM will reach about Mach 2 ~ 3 when launched at sea level with zero initial speed while climbing up to a 4~8 kilometer high target. It will also reach targets no more than 12~24km away. Such is the case with SLAMRAAMs or CLAWS, both of which utilize the AIM-120B missile for short-medium range SAM duties. When launch in a supersonic dash (Mach 1.6~2.0) from a high altitude, while engaging a target at a lower altitude, the AMRAAM achieves much higher speeds. Essentially, it employs the same technique the Phoenix does to maximize its kinematics -- flies a lofted trajectory through the very thin air in the upper atmosphere then dives on the target. With the newer AMRAAMs like the AIM-120C7 and D which has the lengthened motors, maximum speeds can reach ~ mach 4.5. In a typical medium altitude to medium alitude engagement with supersonic release speeds the AMRAAM is roughly a Mach 4 missile.

The Meteor, if you distill it down to the basics, is very much like a VFDR AMRAAM. The seeker, warhead and guidance will be of similar capabilities and yield. What's different is that it is a ducted rocket missile (it is technically NOT a RAMJET even though people like to call it that *see note*). In fact, when the meteor was being planned Raytheon offered a VFDR AMRAAM called the FMRAAM as an alternative to the european program. The motor for such an application, was actually funded and developed (circa 2002) by Aerojet alongside other projects such as the MARC-282 (13.5") and MARC-290 (10") VFDR motors. However, currrently the US armed services have other priorities and there do not seem to be a lot of immediate interest in mounting a VFDR motor on the AMRAAM to extend its reach beyond the 100~150km bracket of the AIM-120D.

We can only guess what the US plans for BVR AAMs in the future will be. But, what we know is that the US tends to shy away from significant changes to its legacy weapons when it is on the threshold of taking a revolutionary step -- so as not to dilute the case for the initiating the new program and/or eat away at its fundings. The US is currently planning what is called the JDRADM (Joint Dual Role Air Dominance Missile) which is to take on both BVR AAM and HARM duties. Full scale development is slated for 2010~2012. Currently, there are a few maturing technologies that may find its way into this next generation US AAM. Among these is the DCS engine (Dual Combustion Scramjet) which promises a cruise speed of ~Mach 6.5. This has been demostrated to work in the HyFly program and is currently being matured for use in AAMs and high speed cruise missiles. The DCS attempts to bridge the gap between a RAMJET and a SCRAMJET. The problem with RAMJETs is that somewhere between Mach 4 and 5 it becomes exponentially less efficient due because of the need to slow down the intake air to subsonic velocities and then accelerate it via combustion pressures to some velocity above Mach 4 ~ 5 to create thrust. SCRAMJETs do not slow down the air to subsonic speeds before introducing the fuel -- it allows the combustion to occur within supersonic flows. SCRAMJETS have been tested successfully up to Mach 10 in vehicles like the X-43. The problem with SCRAMJETs is that it is notorious bad at holding the flame and it doesn't really work well until about Mach 5 ~ 6 or above. The DCS engine works by slowing roughly HALF of the airflow down to RAMJET speeds (subsonic). Fuel is then burnt in a subsonic combustor but the combustion is intentionally kept very fuel rich and air deficient. The exhaust of this combustion is then introduced to the remaining HALF of the airflow which remains supersonic to be burnt completely. Doing so cures most of the flame holding problems and allows the motor to ignite and work at speeds as low as Mach 3. The sustained cruise speed predicted for such a motor is around Mach 6.5 which is in a sweet spot of its own as far as missiles go with regard to kinematics and range.

* Note: Ramjet vs Ducted Rocket -- The biggest difference between the two is that a true Ramjet ignites and burn its fuel using the compressed air from the intakes alone -- like a jet engine minus the rotational compressors. A Ducted Rocket burns its fuel using independent oxidizers then introduce the already ignited but fuel rich exhaust gases of the rocket based pre-combustion to the intake air to be burnt completely. The advantage of ducted rockets is that it can easily be made solid fueled (as is the case with the Meteor) and it never needs to be re-ignited should it momentarily flame out due to intake problems. The disadvantage of Ducted Rockets is that the missile is carrying at least part of the oxidizer it uses and hence as a lower energy content than a true RAMJET. FVDR -- Variable Flow Ducted Rocket -- refers to a Ducted Rocket with the ability to meter its fuel rich combustion exhaust into the main combustor and/or the intake airflow. The Meteor is a VFDR. In the case of the Meteor, the missile burns the solid sustainer grain in a pressure vessel separated from the main combustor by a pintle valve. It works the pintle valve to meter is right amount of fuel rich exhaust to the main combustor depending on the air density (altitude) and thrust desired. To the best of my knowledge its air intakes are fixed.

F-16.net Editor Joined: Sep 23, 2003 Posts: 2832

skrip00 wrote:

Now that the ASRAAM has been improved, and is a competent AAM with a wide variety of capabilities. Will the US purchase them for use on their own F-35s and other aircraft along-side the AIM-9X?

While the AIM-9X has demonstrated LOAL and internal bay use is possible (for the F-35.), owning a bunch of ASRAAMs just to gauge capability and to buy an item from our allies would be a good idea overall.

There are several things that the USAF may want to get for any number of reasons... fill in the blank here _________________________.

The big problem is we don't have any money. This isn't the good old days of the cold war when we had budgets that could get lots of stuff. With current war ops and trying to buy new airframes to replace old ones, USAF really, no kidding, has very very limited funds. Kinda scary even. Things we take for granted like PCS moves, er that is moving people to a new assignment for those that aren't in the know... and numerous other daily things that allow the USAF to run, we are just flat very very low on money after you add up the weapon system purchases, bills to keep facilities running, funding ops and exercises, maintenance and sustainment of current weapon systems ( some very old ). People issues ( training, housing, payroll, healthcare to name just a few things ).... and all this I mention is the short list. I can guarantee that on any given weekly briefing for the big bosses, no where on there is a slide that mentions getting another dogfight missile. The bosses have trouble just making ends meet. $$$ Call us when Iraq is over.

Elite Joined: Jul 30, 2005 Posts: 739 Status: Offline

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Future US purchases of ASRAAM?