Will South Korea reject the F-35 ?

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johnwill

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Unread post05 Mar 2012, 21:40

Photo is meaningless. Whether the missile point is in freestream air or not is irrelevant. Obviously, the airplane needs the extended launcher to safely release the missile. Else, why not just use a lighter, cheaper LAU-147, which you say the F-35 will use. Here's why - the LAU-142 will prevent the missile from flying back into the bay and the LAU-147 "lessens the chance of rebound". Lessen? LESSEN? You better be really sure it eliminates the chance of rebound.
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SpudmanWP

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Unread post05 Mar 2012, 22:20

The LAU-142 was designed the way it was due to the experience at the time. Now add 15+ years of experience on top to the -142 and the -147 can do the same job with a smaller package (eg launch the missile at ~25 fps). A couple of drivers to this ability in a smaller package is telescoping pistons and them being charged at 5000 psi.

Look at the performance comparison.
Code: Select all
Name........Weight.....Stroke.....Speed
LAU-142.....115lb......9 in.......27 fps
LAU-147.....69lb.......7 in.......25 fps


The LAU-147 weighs only 60% of a -142, has only 78% of the stroke, yet achieves 93% of the performance of the -142.

On a similar note, the SDB (a smaller munition in size and weight compared to the AMRAAM) is also launched from with the F-22/35 bays with a velocity of ~25fps without a problem or the need to preposition in the airstream.

--Edit

I doubt that an AMRAAM leaving the F-22 is even touching the full airstream at the end of the -147 stroke due to the F-22 having a jet-blast deflector that deploys at the front of the bay when the bays open.
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wrightwing

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Unread post05 Mar 2012, 22:39

slowman2 wrote: And the F-35 that the US government is trying to unload to foreign customers is worse than the F-16A Block 5/10s of its time. Only two AMRAAMs.


Nope. 4 AMRAAMS at IOC. 6 AMRAAMS ~Block 5/6. You can keep repeating that nonsense, but it won't make it the truth.

http://www.flightglobal.com/news/articl ... 35-347416/
The new shape allows the Meteors to squeeze into the space designed to house four Raytheon AIM-120C7 AMRAAMs.

Lockheed has previously shown off a modified weapons bay door that creates enough room to store as many as six AMRAAMs.


http://www.airforce-magazine.com/Magazi ... ghter.aspx

The F-35’s air-to-air capabilities were developed to give it an edge against the most maneuverable of foreign fighters, since it will be the primary aircraft for most allied air forces.




As for worse than Block 5/10 F-16s, you can't be serious. The F-35 will reach IOC with superior avionics to its peers/foes. It will carry a very flexible warload from the very start. Operate day/night/adverse weather, etc... The early F-16s were basically day fighters with iron bombs. The F-35 is in no way analogous.
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wrightwing

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Unread post05 Mar 2012, 22:46

maus92 wrote:
Prinz_Eugn wrote:Um... no. Just no. IRST's always have a shorter range than comparable radars. Blame the physical laws of the universe.

Umm, maybe yes.

"According to the manufacturer data, the IRST scan volume is comparable to radar, with selectable scan volumes in azimuth and elevation. It can operate in either track-while-scan or single-target-track modes. Additionally, IRST provides autonomous, passive range on targets to develop a weapon-quality solution, as well as track data to enhance target engagement. "

http://defense-update.com/20110721_supe ... pment.html


There's no way that an IRST can scan as far, or as fast, as an AESA radar.
Both the Super Hornet, and the F-35 can detect targets >100nm. There's no way an IRST is going to see a non-afterburning frontal aspect target, at anywhere near that range.
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deadseal

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Unread post05 Mar 2012, 22:51

whoever quoted an IRSTs as being able to have weaopns quality TWS or STT modes at any range usefull in a modern BVR environment is utterly wrong.
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wrightwing

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Unread post05 Mar 2012, 22:57

geogen wrote: I would agree with that assessment.

First of all, any F-35 hitting it's afterburner (with a 60' torch out it's tail) trying to go supersonic into an offensive launch profile will light up like a Christmas tree to any dedicated large aperture IRST in the area 100s of km away.


If an IRST is looking at ranges approaching those numbers, then it's going to have a narrow field of view. It's not going to have a 120-140deg azimuth continuous staring array, that sees any heat source from sea level to 50,000ft. Secondly, the F-35 doesn't have a 60' long afterburner plume.



So right off the F-35 is stuck in a mil power and subsonic launch profile if trying to remain undetected still 100km out. However, the trade-off is this will also likely close the engagement range to a point where each side can get a mutually offsetting launch capability.


See the above comment about the probability of long range detection. Secondly, the F-35 doesn't need to use afterburner, in order to get a kinematic launch advantage against a target that can't see it. Thirdly, we still don't know the maximum dry thrust speed, which may very well be ~M1.2.

And apparently the Lantirn pod used on the ABL test platform would get an active range find of the missile 100s of km away.


Balllistic missiles are not comparable to jets, in terms of IR signatures.
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SpudmanWP

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Unread post05 Mar 2012, 23:02

WR, in case you missed it, it is a laser on the ABL that gauges range, not the IRST.
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sewerrat

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Unread post05 Mar 2012, 23:30

SpudmanWP wrote:WR, in case you missed it, it is a laser on the ABL that gauges range, not the IRST.


Point one: who gives a flying hoot if the Koreans choose the F-35 for anything. It'll be the F-35 providing them with their golden umbrella of safety, none the less. This isn't the F-22 where people were pitching ideas of selling it to Israel to preserve the assembly line.

^ Yeah, using IRST to gauge range to a target is akin to gauging the distances between galaxies based on wavelength/luminosity..... I'm sure the IRST could narrow down the range to plus or minus the width of Atlantic ocean. Now then if you had two or more datalinked -35s separated by 30 miles (plus or minus), I'm sure they could work out a triangulation algorithm to guess'timate distances.
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johnwill

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Unread post05 Mar 2012, 23:54

Spudman,

First it was ---"the LAU-142 does not push the AMRAAM out completely into the airstream"
Next came --- "not enough to even get the point of the nose into the airstream"
Finally, ---"I doubt that an AMRAAM leaving the F-22 is even touching the full airstream "

Sounds like you're making this up as you go along.
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SpudmanWP

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Unread post06 Mar 2012, 00:10

More like as I find out more info I adjust my opinion, it's called "learning". ;)
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maus92

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Unread post06 Mar 2012, 01:05

deadseal wrote:whoever quoted an IRSTs as being able to have weaopns quality TWS or STT modes at any range usefull in a modern BVR environment is utterly wrong.



I think Lockheed Martin says so:

"IRST is a long range sensor system that passively detects and tracks airborne threats in advanced electronic attack and heavy radio frequency/infrared countermeasure environments. The high resolution characteristics of IRST provide dramatically improved raid cell count (40 times more accurate than radar) at maximum declaration ranges – information that can stand alone or be fused with other sensor data to enhance situational awareness, ensuring first-to-see, first-to-shoot capability.

The IRST scan volume is comparable to radar, with selectable scan volumes in azimuth and elevation, and can operate in either track-while-scan or single-target-track modes. Additionally, IRST provides autonomous, passive range on targets to develop a weapon-quality solution, as well as track data to enhance target engagement."

http://www.lockheedmartin.com/content/d ... rst-pc.pdf

And:

"ORLANDO, Fla., February 24, 2012 – Lockheed Martin’s [NYSE:LMT] SpectIR transportable infrared search and track (IRST) pod successfully acquired, tracked and provided a weapons cue during a recent live fire flight test conducted by the Air National Guard (ANG).

The SpectIR pod successfully acquired the target on the first pass and maintained a tight track throughout the engagement, providing the pilot with a passive, weapons-quality cue that enabled weapon employment. By incorporating IRST capabilities into a pod form, the SpectIR system provides long-range, passive infrared detection and tracking of airborne threats in a transportable configuration."

http://www.lockheedmartin.com/us/news/p ... ility.html
Last edited by maus92 on 06 Mar 2012, 01:10, edited 1 time in total.
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SpudmanWP

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Unread post06 Mar 2012, 01:10

Nothing about that declares what is "long range" or what that is relative to.
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maus92

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Unread post06 Mar 2012, 01:14

SpudmanWP wrote:Nothing about that declares what is "long range" or what that is relative to.


Shh, that's a secret...

But you are correct that is doesn't say the ranges, or the level of sensor integration required to maintain the track in various engagement scenarios.

Interesting that LM is trying to position it as a BMD enabler, much like they did with DAS.
Last edited by maus92 on 06 Mar 2012, 01:21, edited 1 time in total.
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delvo

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Unread post06 Mar 2012, 01:15

wrightwing wrote:http://www.flightglobal.com/news/articles/picture-mbda-reveals-clipped-fin-meteor-for-f-35-347416/
The new shape allows the Meteors to squeeze into the space designed to house four Raytheon AIM-120C7 AMRAAMs.
Lockheed has previously shown off a modified weapons bay door that creates enough room to store as many as six AMRAAMs.
The fact that that article talks about clipped fins for Meteor is not as interesting as the fact that they called the missile itself "miniature" compared to the original. The original Meteor's dimensions (not considering fins) were always the same as AMRAAM's: 7" diameter, 144" length. But the problem with putting it in the lower inner spots in an F-35's bays where an AMRAAM goes was that the weight limit there was 350 pounds; an AMRAAM weighs less than that but a Meteor weighs more. I've thought for a while that the solution was pretty simple, to just reduce Meteor's weight by about 15% so it's under the limit. Fins don't weigh much, so you can't do that by clipping them, so the missile's body would need to get either smaller or less dense. Since they're now describing not just the fins but the missile itself as "miniature", it looks like they've done what I predicted. (I presume this means carrying less fuel, so the new version of the missile would be shorter-ranged, but it's starting from a rather long-ranged original, and you can still hang the original from the weapon bay's ceiling and carry both versions at once.)
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SpudmanWP

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Unread post06 Mar 2012, 01:21

"Miniature" might relate to a model of the clipped fin missile, not the missile size itself.

Yep, here is the reference:
A miniature Meteor mock-up featuring four clipped fins appeared for the first time in the company's display at the Air Force Association's Air & Space Conference and Technology Exposition in Washington DC.


As to the IRST for BMD" with the range to target being so large, an IRST for BMD would be fine. It is only there to provide cuing for other sensors anyways.
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