Forum: Program and politics

slowman2 wrote:

river_otter wrote:

If bounceback was a realistic concern to you

It is not a concern of me; it should be the concern of the JSF Office and Lockheed Martin.

And yet they, who both know more about this plane than you ever will be allowed to know, are satisfied that station will be able to launch AMRAAMs. That includes the customer, as well as LM, whose concerns have been satisfied.

slowman2 wrote:

river_otter wrote:

then what do static mock-ups or a non-firing mounting inside an F-35 for a photo op prove that a photoshop mock-up doesn't?

That shows that at least Lockheed Martin is working on mounting the AMRAAM in the A2G station. Right now, they aren't.

popcorn wrote:

They are built by LM after all.

No, they are built by a 3rd party contractor.

Again, can't even keep your own story straight even within the same post. LM isn't the entity who is, or should be, "working on" the mounting at this point, by your own statement. A 3rd party contractor is working on it. In your very next post:

slowman2 wrote:

The contract for this launcher was awarded to Curtiss Wright in 2010...

Wow! And by your own admission it is being worked on, too! Will wonders never cease...

slowman2 wrote:

Japan and Korea need their combat-ready jets by 2016 to replace ancient F-4s falling out of sky and cannot wait until 2025~2030 for the four-AMRAAM capable F-35 to be ready.

That is a legitimate concern, but again, if the solution is to stick their grandchildren with the same problem again down the road, it's not a solution. Even with only two AMRAAMs, the F-35 is a better air superiority fighter than anything else being offered. Like the Lampyridae, which only ever had provision for two missiles maximum, the same calculations Germany ran in the 1980s hold today; a stealth fighter with just two medium-range missiles is essentially unbeatable in air superiority against non-stealth opponents. And unlike Lampyridae, the F-35s Korea would buy today would be upgraded to four or even six AMRAAMs, while maintaining full stealth, just a few years later. Moreover, if it mattered that much, a contract that included provision for Korea and Japan to pay the costs of certifying four sooner would mean that it's not just two even at the moment of delivery.

slowman2 wrote:

riverotter wrote:

In a stealth fighter, the external carriage is optional; internal is priority. Even if they outright deleted the wing stations, it has zero bearing on the function of internal stations 4 and 8.

Ever wonder why the mandatory capability requirment came out to be like this, that is internal armament is optional, while the full external armament is mandatory? The DAPA running the contest doesn't like the F-35 and are looking for an execuse to kick Lockheed Martin out of the contest to please, or at least give an impression of a fair contest to, the EADS Cassidian, Boeing, and Saab so that these guys can make aggressive bids. Lockheed Martin's presence in the contest with the US DoD's full-backing behind it, gives the impression of an unfair contest to other bidders. The DAPA wants their contest to be strictly technical/commercial contest like Indian MRCA, not a political contest like Japan's F-X.

Translation: If they made the contest on the basis of actual measures of capability, the F-35 is a foregone conclusion, the contest an obvious sham. In order to maintain the political theater of a contest rather than a no-bid award to LM, they had to derp up the requirements pretty far, just to even allow other contestants in. If they'd made any internal carriage mandatory at all, then the only entrant is F-35. If they'd weighted internal stealthy carriage equal to its worth vs. external carriage, other planes could enter but only F-35 could win. So no, I never wondered why the contest requirements came out that way. I just wonder sometimes if they can possibly be stupid and/or stubborn enough to sacrifice their current pilots, their children, and their grandchildren, just to maintain the illusion of a fair contest.

slowman2 wrote:

popcorn wrote:

Why should ejecting an AMRAAM from the F-35's internal weapons bay be a problem?

Look at the distance between the ordinance ejector and the air stream below. In F-22, it is pretty close. In F-35, it is pretty distant. Without a sufficient ejection force, the chance of a bounce back is high.

Sufficient ejection force? You mean sort of like the ejection force that accelerates a 2,000 lb. bomb out at 27 fps? Gosh, I hope they can produce enough force to shoot a 300 lb. missile out that fast! What's that equation again, f=a/m^9? Golly, the force to move that missile has gotta be, like, a billion times the force required to move a bomb more than six times the missile's mass!

Plus, I'd like to see your fluid mechanics and statistical calculations for what the chance of bounceback actually is. "High" is so nebulous and meaningless. If you actually know what the chance is, as would be required to make that characterization, it should be no problem for you to tell me exactly what the chance is, and explain how you came to that number. A simple plot of %chance of bounceback vs. ejection force, plus the underlying equations, would suffice. Since as you yourself say, the issue is only with the ejection force being sufficient, that graph should show exactly what a sufficient ejection force is. I'm sure Curtiss-Wright would be happy to find out what ejection force they need to produce. Years ago, LM thought the chance of AMRAAM bounceback was pretty high with the YF-22. Yet the F-22 doesn't have the YF-22's spoiler that was "needed" to prevent it. Turns out, it wasn't a problem at all.

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m wrote:

I’ll give up, it’s like discussing with an autistic

Told you earlier, Slowman has been banned from at least two other defence sites for trolling. Christ, he's banned from StrategyPage...that's like being thrown off deathrow for being a criminal...

I'm sure he's deriving enormous pleasure from you all running around rebutting his spurious arguments which he's trotted out over the last six or so years on multiple sites and never given a damn about anyone actually answering any of the points he makes,

Ian

:: Janitorial Service Message: Slowman2 has been banned. So will other persistent trolls be. ::

Lieven wrote:

:: Janitorial Service Message: Slowman2 has been banned. So will other persistent trolls be. ::

stobiewan wrote:

m wrote:

I’ll give up, it’s like discussing with an autistic

Told you earlier, Slowman has been banned from at least two other defence sites for trolling. Christ, he's banned from StrategyPage...that's like being thrown off deathrow for being a criminal...

I'm sure he's deriving enormous pleasure from you all running around rebutting his spurious arguments which he's trotted out over the last six or so years on multiple sites and never given a damn about anyone actually answering any of the points he makes,

Ian

Some kind of a trap … could have known a discussion was useless.

Quote slowman2: "We are not going to have a constructive discussion until you educate yourself and ……"

Six years trolling and banned from several sites, including Strategy Space … suppose he didn’t learn that much last six years.

Gr. M

johnwill wrote:

The F-22 uses trapezes to move the missiles into the airstream. The F-35 currently does not have trapezes.

The F-22 does not use a trapeze, but a pneumatic launcher, specifically the LAU-142.
http://www.exelisinc.com/solutions/Laun ... fault.aspx

There is a good shot of the LAU-142 in action at he 1:30 mark here:
http://www.youtube.com/watch?v=TNI_MgH5OGw

Just so everyone knows, that F-35 trapeze is designed for the ASRAAM (and likely Aim-9X) as it is a rail launched AIM instead of an electable missile (at least at the velocities needed to clear the bay).

SpudmanWP wrote:

johnwill wrote:

The F-22 uses trapezes to move the missiles into the airstream. The F-35 currently does not have trapezes.

The F-22 does not use a trapeze, but a pneumatic launcher, specifically the LAU-142.
http://www.exelisinc.com/solutions/Laun ... fault.aspx

There is a good shot of the LAU-142 in action at he 1:30 mark here:
http://www.youtube.com/watch?v=TNI_MgH5OGw

Just so everyone knows, that F-35 trapeze is designed for the ASRAAM (and likely Aim-9X) as it is a rail launched AIM instead of an electable missile (at least at the velocities needed to clear the bay).

Right, only the sidewinder uses a trapeze on the Raptor.

Awesome vid spud. Love how fast that thing works!! Reminds me of a great white shark coming out of nowhere to pounce it's prey. Impressive.

The mfg says that at the end of the stroke it's going 27 feet per second.

popcorn wrote:

SpudmanWP wrote:

johnwill wrote:

The F-22 uses trapezes to move the missiles into the airstream. The F-35 currently does not have trapezes.

The F-22 does not use a trapeze, but a pneumatic launcher, specifically the LAU-142.
http://www.exelisinc.com/solutions/Laun ... fault.aspx

There is a good shot of the LAU-142 in action at he 1:30 mark here:
http://www.youtube.com/watch?v=TNI_MgH5OGw

Just so everyone knows, that F-35 trapeze is designed for the ASRAAM (and likely Aim-9X) as it is a rail launched AIM instead of an electable missile (at least at the velocities needed to clear the bay).

Right, only the sidewinder uses a trapeze on the Raptor.

+

Call it whatever you want, it looks like a trapeze to me. The missile is clearly NOT ejected into the free airstream, but is mechanically positioned into the air before it is released.

Spudman,
"trapeze" refers to the folding geometry of the launcher and "pneumatic" refers to launcher's drive type.
Those two aren't mutually exclusive as you seem to think, cause they refer to different aspects of the launcher.

A trapeze positions a missile in the airstream where the missile ignites and leaves the rail. This is how the 9M works on the F-22, the ASRAAM (and likely 9X) on the F-35, the AIM-4 in the F-102, etc.

If you look closely you will notice that the LAU-142 does not push the AMRAAM out completely into the airstream before breaking contact.

btw, Neither the DoD ,nor anyone else, calls the LAU-142 a trapeze launcher.

--Edit

Here are some technical details that I dug up about the BRUs and LAUs from EDO Corp (now ITT).

One new thing is that the LAU-142 is a telescoping piston design that kicks the AMRAAM out at 25fps.

http://www.dtic.mil/ndia/2005psts/seal.pdf

As I said, call it what "DOD ,nor anyone else" (sic) wants. It looks like a trapeze, it functions like a trapeze, it quacks like a..., so, .... By your own statement, it positions the missile into the airstream, completely or not, before it is released. A trapeze doesn't have to move the weapon "completely into the airstream", as it only has to move it far enough to assure safe separation. Rail launch, like the LAU-141, or ejector launch, like the LAU-142, doesn't matter, it still functions like a trapeze.

As you probably know, YF-22 used a device for AMRAAM separation that you would have to agree is a trapeze. The F-22 device is clearly an improvement, but it is not an entirely new design. The Navy A-12 would have used a device with similar geometry for separating all weapons from it's main bays.

But that is all just semantics. The important part of the discussion is that the F-35 does not have any device at this time to position the missile into the airstream (even partially) before launching. The existing door-mounted missile is in the airstream, so it probably will launch successfully. But if a missile is mounted on the heavy weapon hardpoint, some kind of mechanical extension into the airstream will likely be required.

Will these things work on mother-in-laws and drunken relatives? No particular reason.

Why would the A2G station need to position in the airstream? The LAU-147 already ejects at 25 FPS (same range as the F-22's LAU-142) and it can be set at a slight nose-down angle so as to lessen the chance of rebound.

--edit

Here is a shot if the LAU-142 in the bay which gives a good view of the proportions involved. Remember that the stoke length of the LAU-142 is only 9 inches which is not enough to even get the point of the nose into the airstream before separation.

Forum: Program and politics

Will South Korea reject the F-35 ?