Stealth Interceptors not beyond many countries?

Why have we not seen an explosion of faceted-stealth aircraft since the US went public with the Stealth fighter in the late eighties? We do know that the US was not alone in identifying the facet method of radar stealth; MBB in Germany was also working on a stealth fighter independently which used this principle. But I’m surprised that others haven’t followed the US lead.

With the proliferation and evolution of fly by wire technology (required to allow aerodynamically unstable aircraft to fly), and similarly of computer aided design, there is a strong argument that F-117 generation stealth technology is no longer beyond many aircraft manufacturers.

Stealth combat aircraft do pose many operational problems and if stealth is omitted from the equation, are almost certainly less combat capable than a non-stealthy equivalent (weapons load, range, agility etc). Because of emission concerns, ‘total’ stealth technology is easiest employed for offensive strike or reconnaissance aircraft.

Thoughts on a Stealth Interceptor
The problems would be particularly great for a stealth interceptor aircraft; any use of the fighter’s radar immediately gives it way, as does any radio transmissions. Therefore the intercept has to be conducted in a purely passive manner, probably ‘listening’ to encoded target data broadcast by third party radars –itself a risky approach since the enemy can also listen in, creating ghosting, jamming, forewarning and decoding problems. But once close enough passive optical/IR sensors can be used for interception –which also limits the types of air-air missile that can be used, probably to short ranged IR homing types, and presenting launch complications (how to achieve a lock-on before launch if the missile is hidden in a weapons bay etc).

But, even if the stealth interceptor is less intercept-reliable than a conventional design, the fact that it is stealthy gives it a far greater survivability, surprise and menace factor. By menace factor I mean that the enemy pilots and planners will constantly be chasing shadows and on edge disproportionately to the physical ‘footprint’ of the aircraft. And even if the enemy enjoyed a high degree of air-superiority over your territory, the stealth interceptors could still pose a credible threat, picking off just enough enemy to prevent the enemy enjoying air-dominance and the ease of operations that provides –put another way, a limited but stealthy fighter allows the otherwise weaker air force to stand up to the stronger enemy.

I shared my thoughts with an associate and got this nice render of a conceptual stealth interceptor:

It is in part influenced by the MBB stealth fighter project. It has a compound-delta configuration, faceted lines (imagine a sharp blade along its spine and belly) and a single weapons bay which also houses the forward undercarriage. The weapons bay would house one or two IR missiles such as the ASRAAM or Python5. It has provision for radar, but would rely on an IR sensor for stealthy intercepts. It would have a single afterburning turbofan in the 16000lb thrust range, buried in the faceted rear fuselage and fed by a V-shaped air intake with S-bend and similar stealth features.

Although I’m sure there are better configurations, we can immediately see the design challenges. The basic delta configuration, which is the natural choice for faceted stealth, presents many problems, particularly high stalling speeds (limiting agility) and high take-off and landing speeds. To try to reduce this I specified small fixed ‘canard’ wings forward and above the main wing, but these complicate the faceting. There isn’t room for a large or twin engine, unless either the back or belly is made much deeper, or a flat belly/back adopted, compromising the faceted design. Similarly, there seems little space for fuel and/or weapons.

But we know that aircraft designers all over the world can do far better than me when it comes to designing fighter stealth aircraft (lol, don’t worry, I don’t take myself seriously), but why haven’t they?

Umm... maybe the answer is more complex then this, but I’m going out on a limb and say Money.


[edit on 12-12-2005 by WestPoint23]

Not to critic your design to be mean in any way but just some simple observations. The standard canopy is a big radar give away and your design is not stealthy enough. The canopy is highly visiable and would return a big BEEP. The long lateral flat side of the upper rear fuselage is too long and would also represent a huge return path. The lower belly housing of the engine is too deep a presents a challange to desgin landing carriage to keep the fat belly off the tarmac. Stealth relies on multi facet design, just because you have a few facets does not make your design stealthy. Look closely at the front of the F117A there is a long central snout then at least 6 more facets before you get to the cockpit window. Notice how there is no canopy for the cockpit and the edges of the glass are serated. The under belly is totally flat. remember that radar and stealth evasion is based on the principal that the radar is being out and getting returns on the forward and lateral sides of the aircraft, The moment a F117 pitches into a high AOA it becomes somewhat radar visable again.

So you have a trade off, high radar evasion in normal flight requiring a stealthy front and side profile.

It would be very hard to make your design stealthy from the side profile resulting in either lots and lots of facets which begin to eat up internal volume for things like air ducts, exhaust ducts, landing gear bays, electronics, engine support systems etc. Or your airframe becomes so massively huge that your small endeaver becomes a massive manufacturing nightmare and very costly as the raw material use goes up, airframe , wing composite material, wiring, back systems, electrical control components, etc all have to be designed for the larger mass airframe.

This is something a low budget airforce or military budget can not afford.

Why would anyone use facited stealth when computing power exists to make curved stealth?

Thanks for your excellent response. With my artist buddy we can work on improving the stealthiness of the design.

This is the MBB stealth fighter which is the primary influence:

More facets? My understanding, based mainly on naval applications of faceted stealth, is that the fewer facets the better – yes it has a massive reflection from certain angles (perpendicular to any individual surface), but the radar is bounced off away from the source from most angles. At least that’s how it was explained to me, by a chap using a mirror to show me what he meant. Is that wrong?

Now, I don’t think that the deep belly is the problem you suggest but it’d take someone who can draw to explain the shapes in my head, lol.

I thought this image ad somthin to do with the German firm MBB. I heard they were going to build a stealth fighter but the US had id cancelled for some reason. Why do the US have to spoil everything, Ok i do admire thier aircraft still but the Germans could have at least had a try.

The US have killed alot of things like the British aviation industry, The TSR2 Interceptor, The British EM-2 Bullpup Rifle and now this Stealth Aircraft.

They even cancelled the exporting of the F-14 Tomcat too (Exept for Iran).

Also, These UCAV have better designs then the manned fighters now.

[edit on 12-12-2005 by Browno]

Of same design as in original post

I’ve done some internet research re why facets work in order to work out whether my “fewer facets = better” was correct. My understanding seems right. For example this picture shows how faceted angles deflect radar away from the source:


I also looked up Have-Blue, the stealth demonstrator which preceded the F-117:

Note how comparatively few angles of slope there are.

Lastly I looked back at the various stealth naval vessels, all have relatively flat sides with few angles. The most obvious is this US design:

Note that MANY countries design and build ships with such faceted stealth. Sweden is a world leader… so why not aircraft?

I still think it makes sense that the fewer angles the better. Slab sides at constant slope is in! lol.

Originally posted by Browno
The US have killed alot of things like the British aviation industry, The TSR2 Interceptor, The British EM-2 Bullpup Rifle and now this Stealth Aircraft.

That was one of the worst service rifles in the history of warfare, and it had everything to do with the mechanical systems, wieght, and poor ergonomics, and absolutely NOTHING to do with the US.

Originally posted by planeman

Lastly I looked back at the various stealth naval vessels, all have relatively flat sides with few angles. The most obvious is this US design:

Note that MANY countries design and build ships with such faceted stealth. Sweden is a world leader… so why not aircraft?

I still think it makes sense that the fewer angles the better. Slab sides at constant slope is in! lol.

You do know that the vessel you have posted is not swedish, but an advanced US concept by Lockheed martin right? That ship was undergoing secret testing in San Diego for 10 years. People reported seeing a very strange looking ship a few times at night. They finally released it to the public a few years back and if your lucky, you can still catch a glimpse of it from time to time if your in San Diego.

Train

Originally posted by Browno
I thought this image ad somthin to do with the German firm MBB. I heard they were going to build a stealth fighter but the US had id cancelled for some reason. Why do the US have to spoil everything, Ok i do admire thier aircraft still but the Germans could have at least had a try.

Umm, to clarify:
The US asked, not told, not demanded, not made, Germany to consider cancelling said 'Lampyridae' program (test demonstrator), and in exchange, Germany was offered to join the X-31 studies/research. Germany agreed.
Check down on page 20 of this .pdf, and you will see:

X-31 Demonstrator Aircraft Project
(Germany, U.S.A.)

seekerof

[edit on 12-12-2005 by Seekerof]

Originally posted by BigTrain
You do know that the vessel you have posted is not swedish, but an advanced US concept by Lockheed martin right? That ship was undergoing secret testing in San Diego for 10 years. People reported seeing a very strange looking ship a few times at night. They finally released it to the public a few years back and if your lucky, you can still catch a glimpse of it from time to time if your in San Diego.

Train

If you look above the pic you'll see where he says "this US design."

The problem is that foe someone to develop a stealth craft it has to begin from square 1, as the exercise points out the development was based on the nighthawk design which is 70's Skunkworks technology.

So lets say you spend billion developing your stealth-craft which I suspect is more difficult than what it seems and that raw computer power doesn't cut it. Then you have a plane that is 30 years behind the US, so after spending all that money you will have an old aircraft. So then you developed our own Tacit Blue to demonstrate curved stealth and it took you 10 years or so to get to that point. But that time the US will have flying hypersonic stealth bombers that will be out of your territory before your plane has the change of leaving the runway.

So you see unless you can come up with a totally radial concept not based in any current technology that is years ahead of everything now it is pointless to run a catchup race that is going to cost you the money that you don't have and that will take you nowhere.

[edit on 12-12-2005 by carcharodon]

There is no reason you could not "skip" the faceted stealth and go right to the curved stealth. The computing power exists in Europe and Japan, and presumably Russia.

The problem is, can you afford it?

You see what the US got with it's F-22 and you can see the F-35 getting more and more expensive. Having the best plane design in the world doesn't do you much good if you can't build it.

Going back to the basics of the thread, I don't think a faceted stealthy interceptor is of much use and that is why nobody has built one.

One of the key facts about why the faceted design of the F-117 works is that it flies subsonically, this means there is much reduced kinetic heating of the skin and almost no consideration to (here I go again) transonic drag. If the F-117 were to be given enough power to fly at mach 2 (a minimum requirement for an interceptor) then you would see it coming like a big searchlight and so faceted stealth is no good at all.

To see how its done properly look no further than the F-22, but then as AMM said, look at the cost.

RCS can be (and is) reduced in much more 'cost effective' ways for less fortunate Air Force's ranging from the RAF's 'stealth tape' for its Tornadoes etc to the limited stealth design of the Typhoon and even the Mako trainer. Full stealth however imposes too many compromises on performance that need to be solved at huge expense and for the small defence budgets of European nations it isn't worth it.

The obvious answer would be a completely pan European, full stealth fighter of roughly 2/3 the size of the Raptor. This is technologically perfectly feasible for us, but as this would need France, Britain, Sweden et al, ALL to agree on workshares, production arrangements, export responsibilities etc it will never happen.;

[edit on 13-12-2005 by waynos]

Here is real continuation of MBB Lampyridae project: link

Originally posted by matej
Here is real continuation of MBB Lampyridae project: link

Hmm... the second to last photo in that link looks like some of those UFOs people see over there in the UFO forum......

I agree that a stealth interceptor would be a good idea. I have often wondered why no one inculding the US has ever built a dedicated Air Defense Fighter and Interceptor. In theory, it should be easier and less expensive then a plane like the F-22. Interceptors don't need as much agility as the F-22 and they can be heavier. Interceptors are used against bombers, heavy attack, and cruise missiles. None of these aircraft are extreemly agile.

Tim

Hmmm… drag seems the enemy as usual. But, would it really need to go Mach 2 or is that just an ideal that, if stealth is factored in, is less important?

If the design was subsonic, it would switch from a pure interceptor to a roving fighter(?).

And as for being 30 years behind the US, so what? That doesn’t affect its utility.
Anyway, here’s a better render. The Swedish emblems are a joke BTW.

I think that a mach 2 speed is essential for an interceptor (the more the better). More so than in any other type of aircraft as the main function of interception is to engage the approaching enemy ASAP, you can never intercept an enemy attack too soon. This is true whether you are trying to catch a supersonic raider like the Tornado or if you are trying to intercept a subsonic stealthy raider (assuming you can find them) the further away from your shores the interception takes place the better it is (not least as a message to the bad guy of how good you are).

Therefore in an interceptor the main preresquisites are an accurate and reliable weapons system and an eyeball bursting max speed and climb rate, stealth doesn't reeally come into it because you are not trying to hide, you are just trying to get the other guy as quickly as possible.

So, where might stealthiness be useful here? As far as I can see it is purely as a means of making sure the enemy bomber, or his escorting fighters, if any, don't see you before you can get a shot off of your own, however if this degrades your own performance to the point where the interception is taking place virtually over the target when a faster fighter could have made the interception over the sea, is it worth it?

Clearly here I am thinking purely in terms of defending the UK and European countries, which allows for very little reaction time to an incoming raid, unlike somewhere like the USA where all adversaries are quite distant.