Register here

Recent Posts

Pages: [1] 2 3 ... 10
1
Aerospace / Re: Japanese next generation fighter study (aka i3, F-3)
« Last post by Blitzo on Today at 02:00:24 pm »
IMOHO (and as shown by the above discussion) Japan and UK share the same defensive need: projected defense in contrary to air dominance that is known more through its offensive side. If the F-22/35 hybrid wasn't deemed to satisfy the Japanese, a joint UK/Japan fighter and system strategy (carrier/offshored based missile fregates) might have plenty of advantages past their similarities. On the industrial side, there are plenty of parallel that can be drawn (with its fair share of conflicting needs as well) . The clever part will be then to aggregate some of the European needs since at the age of permanent war, foreign basing will be compromised at a partner level and in A Vs B scenario. So this defensive fighter design might well be correlated with an offensive 21st century's version of a JABO twin.

The level of political, industrial and military coordination to make a joint venture like that work would be very immense. It's not like the UK selling Australia a modified T26 where Australia is the obvious junior industry partner and recipient of technologies and expertise -- a UK and Japan venture will mean both sides want an equal slice of the pie and equal contributions and say into the project. Such an arrangement will almost inevitably mean delays and cost overruns, though it will probably produce a good fighter at the end of it.

If Japan wants to bring in foreign expertise for F-3, I do not expect a an equal share of the work for Japan and a foreign partner, but rather for Japan to provide the bulk of the work and leadership while the foreign expertise merely brings in some additional technologies as a junior partner.
2
Military / Re: Bradley Replacement - OMFV
« Last post by jsport on Today at 01:51:31 pm »
The Next Generation Combat Vehicle program has begun to firm up its desires for the Bradley replacement, which it has now dubbed the Optionally Manned Fighting Vehicle. Similarly to MPF, the Army is accelerating this program massively and now wishes to begin fielding it in 2026 rather than in the mid-2030s as it envisioned after GCV was killed. Breaking Defense has a decently comprehensive article giving a rundown of what the Army's looking for and who the likely bidders are. Here's some highlights.

Quote
General Dynamics looks like the early favorite to replace the Army’s 1980s-vintage M2 Bradley troop carrier. That’s my personal assessment after talking at length to officers and contractors at last week’s Association of the US Army conference, where months of uncertainty finally gave way to some real clarity about both what the Army wants and what industry can offer.

In brief, GD’s Griffin III demonstrator seems to hit the sweet spot between innovative and proven technologies that the Army wants to start fielding a Next Generation Combat Vehicle (NGCV) as soon as 2026. Of the three vehicles on display at AUSA,

  • BAE System’s CV90 Mark IV is the latest upgrade of a 25-year-old vehicle widely used in Europe;
  • the Rheinmetall-Raytheon Lynx is an all-new design, although individual components have a good track record;
  • but the General Dynamics Griffin III is in the middle, combining a new gun and new electronics with the time-tested chassis from the European ASCOD family.
Quote
Schirmer offered more specifics. “We have a pretty challenging test schedule… very similar to MPF, (so) we really can’t afford a clean sheet design,” he said. The more mature the component technologies, the better, he said, but what’s best is that those individual components have been proven as an integrated system.

Specifically, Schirmer said, “for the Bradley replacement, we are going to be buying vehicles that are based on a mature architecture — powertrain, track, suspension — that’s already in service somewhere in the world.”

Mature architecture was developed some time ago and would tweaking but surly is not "on the market"

https://www.globalsecurity.org/military/systems/ground/cattb.htm

"The CATTB chassis was a modified M-1A1 tank hull. It featured a new propulsion package, new track and suspension designs and the Army's new "Vehicle Electronic System (called Vetronics). The turret was redesigned to carry two crew members instead of the three required in the MlA turret. There was a commander and gunner but no loader. The turret was designed to accommodate an advanced tank cannon system that included a new lightweight 120mm gun and an automatic loader.

Several changes were made in the hull: floor blow off panel removed; reduce hole in middle bulkhead; extending hull casting plate; reduce hight of rear bulkhead. The M1A1 hull was used and modified where necessary to assure strength and space utilization. However "modern" APFSDS (which means that ammunition, that was availble to Soviet-Russia back then) does "bounce" at angles below 10°. This is why the glacis was considered safe, despite being only ~310mm thick. The fuzes of shaped charges warheads as used on ATGMs, HEAT ammo and RPGs have problems with fuzing at high angles of impact. Even modern fuzes as used on the Panzerfaust-3 RPG from Germany have trouble at fuzing at angles below 15°.

The CATTB's power was provided by the diese1 version of the Army's Advanced Integrated Propulsion System (AIPS) developed by the Cummins Engine Company. It was one of two competing propulsion systems then under development for use in the next generation of heavy combat vehicles. The other concept used a gas turbine engine and was developed by General Electric.

The Cummins AIPS engine was a V-l2, l682-cubic-inch turbocharged diesel that developed 1450 horsepower. It differed from existing diesels in several ways. For one thing, it used advanced heat-resistant materials that enabled it to retain part of the combustion heat, normally rejected to the cooling system, which appeared as additional energy in the exhaust gas entering the turbocharger. Another important difference was that this engine is cooled by oil rather than water. The same oil that provideed lubrication was pumped through the engine where necessary to cool it. Then it flowed through a radiator, where it rejected the heat just as a water-based coolant does in a conventional system.

The oil was a special high-temperature diesel lubricant that can withstand higher temperatures than other types of oil. An important advantage of these difference wa that the amount of heat rejected to the cooling system was reduced substantially and was easier to transfer to the atmosphere. As a result, the cooling system was much more compact. The 240 horsepower normally needed to run cooling fans in a 1500-horsepower diesel tank engine was cut in half. Fuel economy is also improved because there was more power available to move the vehicle for the same rate of fuel flow.

The transmission in the Cummins concept was a seven-speed automatic built by the Allison Transmiion Diviion of Germany's Zahnradfabrik Friedrichshaten AG (formerly a General Motors division). It provides three more gear ratios than the Ml-series tank's four-speed gearbox, and it was designed to allow the engine to be mounted transversely rather than longitudinally to make more efficient use of engine-compartment space.

Another CATTB feature was a new track design that had 50 percent fewer parts than the standard M1 track and was expected to provide longer life and reduce operating and maintenance costs. In the current design, two 9-inch- wide track shoes are mounted side by side and span the width of the track pins. Track guides (prongs that extend between dual sets of road wheel to keep the track properly aligned as it rotates around the wheels) are bolted between the hoes. The new track, on the other hand, uses a single 25-inch-wide shoe to pan the pins, and the track guide is an integral part of the shoe.

This track was designed as a high-durability track. By using a single shoe to span the full width of the track pins, the design uniformly distributed pin loading and bushing pressure, which helped to increase track life. Designers hoped to get 5,000 to 6,000 miles of track life, compared to about 2,000 miles with the standard track.

The CATTB has a new suspension concept that represeted a dramatic departure from the traditional design. Tanks currently use a torsion-bar suspension. In such a system, one torsion bar for each road wheel is mounted transversely inside the hull. One end of each bar is anchored to the hull, while the other end is attached to a road arm, which extends downward from the hull and is connected to a road wheel and shock absorber. As the track encounters a bump, each road wheel is kicked upward, and the torsion bar end of each arm pivots. This causes the bar to twist, and the bar's resistance to being twisted creates the opposing spring force that provides the needed cushion between the vehicle and the terrain.

In the new design, all components were outside the hull. The concept had no torsion bars, but instead fea tured a different type of spring that, along with the shock absorber, was located within each road arm. The system was thus referred to as the external suspension. The external suspension spring differed from conventional mechanical leaf, coil, and torsion-bar systern in that it was hydropneumatic. It consisted of a cylinder filled with nitrogen under high pressure and a piston situated at the top of the cylinder. When the vehicle track encountered bumps, each piston, which was mechanically linked to the vehicle hull, remained stationary while each road wheel forceed its respective cylinder to move upward. This causes the nitrogen to compress and act much like a mechanical spring, The CATTB was set up to test two versions of the system, one by Cadillac Gage, which was tested first, and tbe other by Teledyne-Continental Motors.

The concept would have two significant advantage over conventional designs, First, elimination of torsion bars would mean designers could either provide more space inside the hull, or lower vehicle silhouette to make enemy detection more difficult. Also, it would mean a weight saving of about 1,000 pounds in a heavy combat vehicle.

The SAVA was developed by Armored Vehicle Technology Associates (AVTA), a joint venture comprising FMC Corporation and General Dynamic Land Systems, in conjunction with General Electric and Texas Instruments. It was designed as a computer- controlled system with common hardware and software modules that would be suitable for both combat and tactical vehicles. It integrated the electronic subsystems and simplified the complex vehicle wiring harnesses now in use. The control and display functions were standardized and common for ali subsystems, thereby making vehicle operation easier.
3
Aerospace / Re: Japanese next generation fighter study (aka i3, F-3)
« Last post by Blitzo on Today at 01:49:31 pm »
Well, as an absolute example - imagine Russian tu-160(quite a valid concern for Japan, too) with full missile load(x-102, 12 units), being capable to launch missiles far to the East of Honshu, while covering all the distance in unobservable international airspace clockwise, down low.
This way, not only launcher and missiles won't be observed, but missiles will be able to use all-low trajectory with essentially as many waypoints as will be necessary. They can even wait for launcher or other assets to alert another direction and draw defence attention there, untill it is too late.

H-6k can't go that far, sure, and its missiles are far shorter-ranged. But they are far more numerous, and they still can attack from, say, extreme South or even SSE. And, unlike my example with blackjack, it can be escorted by both fighters and new chinese escort jammers.

 F-3 planners has to take into account not just h-6s, bears and blackjacks, but future Chinese and Russian developments, full usage of chinese SCS bases, even for possible non-friendly Taiwan, just in case.

I do understand the threat that bomber launched ALCMs may pose and the desire for F-3 to be able to intercept the launch platforms, but I was more thinking that in the PLA case, the threat of bomber launched ALCMs will probably only make up a fraction of the overall LACM arsenal that the PLA could be able to use against the JSDF in event of a war.
So I was wondering whether F-3s would actually be intended to be used in a bomber interception role primarily and if it would have been designed around that as a core requirement. But it seems like you are talking about the full range of air to air missions as well, so that makes more sense to me.
4
Military / Re: Bradley Replacement - OMFV
« Last post by TomS on Today at 01:23:05 pm »
An optionally manned troop carrier?  Uh huh. 
5
I seem to recall some think tank recommending trading maybe 300 F-35s in order to achieve the planned number of 381 F-22s.

That's not a very high standard of evidence.

Remarkably few critics? By what standard?

Math. F-35 critics were thin on the ground, prior to 2013. In relative terms - the F-35 by that time had never undergone the kind of shellacking handed out to the F-22 (Baltimore Sun scored a Pulitzer) or the B-2 (the 60 Minutes hit job and others too numerous to mention). And no program before the F-35 had quite as many paid shills.
 
What really happened was still an extremely poor decision.

Was it really? The F-22 has a range problem, is costly to operate, and apparently difficult to upgrade; and Gates was being told that the F-35 was 400-600 per cent better in A2A than anything else out there, and that China wouldn't have many stealth aircraft until 2025. We may regret the decision now but it was logical at the time.
6
Military / Re: F-22s may have been lost as a result of Hurricane Michael
« Last post by TomS on Today at 01:05:43 pm »
22 is the figure given here:

https://eu.pnj.com/story/news/2018/10/17/hurricane-michael-tyndall-air-force-base-f-22-raptors-damage-uncertain/1652997002/

By unnamed "experts." 

There were something like 55 F-22s assigned there.  I'm very doubtful that 40% of those were unflyable.  I'd bet that number is more like 22 total aircraft, including the QF-16s, T-38s, and maybe even the contractor MU-2s. 
7
Military / Re: F-22s may have been lost as a result of Hurricane Michael
« Last post by malipa on Today at 12:18:28 pm »
Nice no viscosity assumption in that calculation, but it doesn't give realistic answers ;).
8
A fighter will have greater maneuverability options than an RV. This hypothetical AAM is going to end up costing $10M a copy, need to be carried externally, and the launching platform won't be stealthy such that the 6th gen AC can kill it first or at least get off the first shot of put the launching AC on the defensive.

A fighter can only use the advantage of maneuverability if the pilot knows he's under attack in time to actually do anything about it. As for stealth, there's no reason it need be carried externally.  Now if you have a large missile, with multiple KKVs, it's likely going to be launched at long range anyway.  Against true stealth aircraft this may be academic anyway as you need to be able to see the other guy to shoot him.  Not all aircraft fit that description however.
9
The Bar / RIP Paul Allen
« Last post by galgot on Today at 10:25:36 am »
Was in Seattle last week,
Visited both Flying Heritage & Combat Armor Museum and Living Computers: Museum + Labs, beautiful places.
Came back to France just to see on the news that paul Allen died  :'(
RIP Monsieur.
10
A fighter will have greater maneuverability options than an RV. This hypothetical AAM is going to end up costing $10M a copy, need to be carried externally, and the launching platform won't be stealthy such that the 6th gen AC can kill it first or at least get off the first shot of put the launching AC on the defensive.

Pages: [1] 2 3 ... 10