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Bispro In reply to Edward-55 [2015-06-25 12:06:47 +0000 UTC]

Thanks a lot!

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Bispro In reply to EricJ562 [2012-12-26 02:50:34 +0000 UTC]

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Bispro In reply to RomaniaTricolor [2011-08-07 11:59:43 +0000 UTC]

Gosh, a twin-tailed F-5! I think I saw it before but never realized it was for real! No wonder the Americans are pissed off by the Iranians... LOL! Thanks for the link.

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RomaniaTricolor In reply to Bispro [2011-08-07 14:57:27 +0000 UTC]

If is ok with you, can I make a suggestion?..since I've made you laugh and all that...
It's something that I've "invented" as the "PAJURA configuration" ("pajura" means "golden eagle" in my language), is something that it came up to me some while ago, inspired by the Henry Coanda's 1910 "jet plane", thinking at stealth characteristics and the huge amount of wasted space inside modern jetfighters design used for the air to reach the engine starting with the intake(this space could be used for fuel or internal bay weapons).

Here how it goes. 3 innovations:

1- Imagine a classic twin engine F-5 without any vertical tail surface for yaw or elevator surfaces for pitch, but instead has only...4 wings! 2 pairs made by 2 wings on the right, 2 wings on the left, one on top of the other and and both jointed at tips! That's right, a...biplane with jointed tips Now, these wings are positioned a little more towards back than usual, in the elevators place! Between the wings we put the...vertical surfaces! (2 or 3 small pieces between each pair of wings) This way we have some advantages: stealth configuration because they are hidden by the jointed wings, they provide extra strenght to the wings (besides the jointed tips) and also a better "Coanda effect" of flowing/attaching air! Needless to say that the ai flowing above the upper wings wil run faster than the one flowing above the lower wings, hence more lift. Aslo they could be in the same line with the external weapons pods. The beauty is also that this configuration is very good for cargo planes! Imagine a Hercules or a Spartan or even better, a C-17 Globemaster III or an Airbus-400 with only these 4 wings! This way the entire very tall and metal fatigue g-force stressing vertical tails are extinct together with the elevators! Obviously, in the cargoplanes examples, the other 2 lower wings will have the bases in the lateral landing gears areas; so in the case of jetfighters, these 2 pairs of jointed upper/lower wings will have the bases above and below the engines. And this is important because...

...the engines. The second innovation is about the engines. Here it goes again. Imagine the engines of this F-5 inverted with 180 degrees! The front of them with the intake blades becomes the back and the back with the hot gases becomes the front. Why, you may ask, since the air will obviously will flow from back to front? Will the jetplane will lfy backwards? No,because it will not! When you look at the engines from transversal view, they are in fact just 2 tangential circles with 2 spaces up and down between them. So the upper "space" will be used as a common exaust for both engines! That's right, the air is flowing from the back towards the front but the resulting faster hot air is collected in a common space (that is the upper "triangular" space between the trasversal section while the lowers space is used for landing hook and maybe rocket storage) and is "shot" backwards! And of course you may ask: where are the intakes? Well, they are...between the wings at the base of them, way back, hidden by the wings just like the vertical surfaces. In conclusion, the air enters between the 4 wings through 2 intakes (one for each pair of wings), makes a small "U-turn", entres into the engine, flowing towards front, after the burning is collected (and makes another "U-turn") by a common "tunnel" situated in the upper space between the engines and is out through the back!
What are the advantages? No more intakes in the middle of the jetplane but way back hidden between the 4 wings! this way the design will be much stealthier and uninterrupted by the classic intakes and extra space (used in the classic designs for flowing air from intakes to engines) is gained.

3-the JAGGED leading edges of the wings. The final innovation. Why the hell should we have jagged leading edges in front of the wings? Because these are combining the characteristics of two types of wings: the lower speed angle used for landing/take-off like an F-18 Superhornet and pointed angle of the fast speed wings like the deltas of the Rafale! I mean, why the hell should we have jets like F-14 Tomcat or F-11 Aardvark or B-1 Lancer with complicated and technological swing wings systems when we can simply have...jagged leading edges on normal wings like F-18 or F-5? The only thing I don't know is if these jagged edges (the owls have such small characteristic feathers for a stealthier approache) could perform well in supersonic speed or what is their radar reflections towards front.

There you go: the Pajura Configuration.
What do you think?

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Bispro In reply to RomaniaTricolor [2011-08-07 16:48:32 +0000 UTC]

Wow! There are a couple of details I have not understood clearly here, but I'll re-read it later with the right frame of mind. Please feel free to send me an e-mail if you wish so. You can also send me a sketch or two to help. The way I see it in my mind, the Pajura's general configuration resembles an X-Wing fighter from Star Wars when the wings on each side are joined (except here we have a space in between). What I don't understand is 1°) where exactly do you put the engines 2°) what type of engines would they be and 3°) how does it all relate to Coanda's 1909-10 design?

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RomaniaTricolor In reply to Bispro [2011-08-07 20:50:46 +0000 UTC]

I will send tomorrow probably a general sketch but so far you got it right 100%. It truly is like a sort of "X-wing"-ish with a space between the wings.

The engines, classic turbofans, are located in the back of the aircraft, normally in the same parallel classic configuration like in any modern twin engine jetfigters but just...backwords (and this is the connection with Coanda's 1910 model, when I was looking at it, thinking how he has placed his engine in the nose of the aircraft rather than in the tail, that was the "trigger" moment because for a second in my mind I involuntary just "reversed" the aircraft, seeing the front at the back and viceversa. This "vision" was enough to spawn wery fast all the others characteristics explained above, it was exactly like a "coupe-de-foudre".

I simply pulled out the "binocular"(that's how I call the engines because they generally look like the object in question) from the airframe, and reverse them 180 transversally and put them back. Just looking trough a binocular like George W. Bush! You know, "Hey, that's the front, genius!" The result being that the air/hot gas is going in the wrong direction so I had to reverse it towards the aft again, the only way to do that was through a common shaft which was the upper space between the engines. If you look at the modern twin jetfighters, you will notest that there is a space between the engines. This space is usually used for the single vertical tail components like a Rafale's or Typhoon's or is unused like in the case of F-18. You know, is like trying to look through the binocular holding it with both hands, on the upper space between 8 fingers will meet while on the lower space the 2 thumbs will meet.

The unexpected advantage (and I forgot to mention it in the innovatios) is this common exaust "triangular" upper space, the beauty is that at the end of it I can add 3 thrust vector paddles making the nozzle like in the Rockwell MBB X-31 demostrator (but unlike X-31, I've reversed their positions, one paddle is in fact up and the two other "lower ones" are sideways). The single common exaust is not round like the F-18's or rectangular like the F-22's but obviously triangular. If you look at this Pajura configuration transversal aft section, the 4 wings are creating some sort of romboidal shape (the upper wings are lowered a little towards the tips while the lower ones are rised more towards the tips). When you put the 2 engines between them in the middle, is easy to see the remaining spaces, in particular the upper and lower triangles made by the circles (engines) and the wings. These spaces are my interest, the upper for the common exaust and the lower for the tailing hook and rockets (whatever).

The main reason for reversing the engines was simply to create the intakes between the wings way back at the stern of the aircraft. Because they are in fact parallel with the engines (the entering air being forced to make that U-turn), no engine blades are visible because they are positioned towards the stern and covered! It's impossible to see them (unless we can create some sort of opening pannels for checking personnel). This is one of the kick ass stealth characteristic of the configuration. Today if we look at stealth jetfighters designs we see that every single one of them is trying to cope with the visible blades, very radar reflective so they have the intakes not quite in front of the engines but posinioned in "winding snake like" locations and that takes a lot of unused space from the aircraft that should be in fact filled with fuel or armament. Because of this, the 4 wings could be thinner because is no need for them to carry fuel.

Another aspect, in some jetfighters, the intakes are covered during some take-offs from rough airstrips, above them some other pannels are opening (the russian jets such as Mig-29 or the Sukhois are the perfect examples). Obviously, in the Pajura config, because the intakes are way back and between the wings, thes pannels are situated at the base of the upper wings.

Regarding the vertical yaw surfaces, situated between the wings, the thing is the 4 wings are enough for the 3 axis fly-by-wire controls but I like them besides their original position also because they can be used in landing as airbrakes.

And final 4 things:
-both navy and airforce air-to-air refueling systems should be present (the F-35 B and C have the Navy probe-and-drogue system on the side while the A has the airforce's boom-and-receptacle behind the pilot) as a precaution measure.
-the shape of the aircrafts front section should be more like the SR-71's (except for the canopy, should be more fitted for visibility), I love the "stealthy" lines of that bird.
-the aircraft could be fitted with a towed radar decoy and an aft small radar, these 2 could be located either closer to the engines like in the russian jets or in the jointed tips of the wings.
-the Pajura config. could also be a VSTOL, because cold air of the turbofan engines will be guided towards a front nozzle exaust through a common shaft where the "lower space" is. The back is not a problem, the hot gases could be guided easily towards ground but the only problem that I'm still unable to manage is the location of the tailhook (I know, I'm a perfectionist too sometimes, trying to cover all the angles) because the hot lifting exaust will be there. I know I'm trying to make the Pajura a "Jack of all trades" combining in one single configuration all the 3 from F-35, the only thing that it doesn't work is that the 4 wings cannot be folded for a carrier (but who knows, maybe the vertical yaw surfaces closest to the tips could serve also as joints for the folding wing tips).

Ok, enough with all these, my head hurts, I will come up with some sketches, I'm not an "artist" but I will manage.

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Bispro In reply to RomaniaTricolor [2011-08-07 21:16:09 +0000 UTC]

Okay, looking forward!

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RomaniaTricolor In reply to Bispro [2011-08-08 04:21:09 +0000 UTC]

After 2 hours in Paint here it is: [link]

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Bispro In reply to RomaniaTricolor [2011-08-08 10:33:09 +0000 UTC]

Thanks. I already posted a reply! Will work on it soon...

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RomaniaTricolor In reply to RomaniaTricolor [2011-08-07 20:56:49 +0000 UTC]

Errata:
I made one mistake about the thrust vectoring paddles: they are in the same position as the X-31's, no different reversed. My apologies. This happens when too many toughts are involved.

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RomaniaTricolor In reply to RomaniaTricolor [2011-08-07 15:04:29 +0000 UTC]

And another advantage for the common inverted engine exaust: less powerfull engines used because the resulting common jet.

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Bispro In reply to Roddy1990 [2010-11-23 15:44:38 +0000 UTC]

Ha ha! Glad you like the StarViper!

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Bispro In reply to AerospacerJ [2010-11-05 09:32:30 +0000 UTC]

Adding PAK-FA features? Good idea! I may give it a go...
Thanks for visiting and for your nice comment!
And make sure to visit my aircraft gallery. There's plenty more stuff there to make you smile...

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