Sukhoi T-75 LTS (CheckMate)

Avimimus said:
XaHyMaH said:
VTOLicious said:
A Pelikan Tail is actually different:
https://www.secretprojects.co.uk/threads/boeing-jast-jsf-x-32-projects.2121/post-18031
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Aerodynamically it's the same - a combination of horizontal and slanted control surfaces.
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Except that it probably isn't - since the elevons can deflect independently. That said, I can definitely see the analogy.
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I consider a true 'Pelican Tail' e.g. the one on YF-23, and the one now flying on Boeing´s ATS. Those are slanted more to the horizontal plane, the angle is about 45°.
 
trose213 said:
Geo said:
Supercruise 1,8 M? Range without external tanks 2900 km? It's magic plane?
View: https://youtu.be/prNmXfyK8oI
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No, it uses new physical principles.
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Nah it sounds like they are just giving the most optimistic subsonic high elevation ferry range of the lts. Every company will give the best possible parameters for their aircraft. I remember back in the day the block 50 f-16 slotted array radar gave a huge range of detection and in the fine print it mentioned that the range of detection was based upon large cargo or passenger planes. This was before normies like me were told about the industry standard radar cross section at that time of five meters squared.
 
Also key to remember the huge amount of work that went into majorly increasing the fuel fraction of the Su-57, such as a gas-based fire suppression system that eliminated foam in the tanks, increasing fuel load by 15 percent for the same volume if I recall correctly.

All the materials and techniques developed for Su-57 could easily make a surprisingly high performance single engine fighter.
 
TMA1 said:
trose213 said:
Geo said:
Supercruise 1,8 M? Range without external tanks 2900 km? It's magic plane?
View: https://youtu.be/prNmXfyK8oI
Click to expand...
No, it uses new physical principles.
Click to expand...
Nah it sounds like they are just giving the most optimistic subsonic high elevation ferry range of the lts. Every company will give the best possible parameters for their aircraft. I remember back in the day the block 50 f-16 slotted array radar gave a huge range of detection and in the fine print it mentioned that the range of detection was based upon large cargo or passenger planes. This was before normies like me were told about the industry standard radar cross section at that time of five meters squared.
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It's being cited as a combat range.
 
Saber said:
Also key to remember the huge amount of work that went into majorly increasing the fuel fraction of the Su-57, such as a gas-based fire suppression system that eliminated foam in the tanks, increasing fuel load by 15 percent for the same volume if I recall correctly.
Click to expand...
I remember speculating about that possibility, but do you have actual quotes or data supporting that?
 
LMFS said:
The key here is to watch the aircraft's presentation in Russian and see what they are actually saying... it is just a pity that the captions are not as accurate as we would like to...
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The article is written by a Vladimir Karnozov, who appears to have been there, and has done all of the Flight reporting from MAKS - and if they intend marketing it in the rest of the world, inviting Flight's Moscow correspondent would be pretty much mandatory.
 
perhaps not so much new information but
https://www.interfax.ru/russia/781148
it says Checkmate will be made in KNAAPO/KNAAZ (wow, they must be busy with making this, the Su-57, Su-35 as well as other aircraft)
they are working on the first prototype for static tests
First flight 2023, deliveries in 2026
According to developers, carry 7400kg payload, cover up to 3000 km, simultaneously engage 6 targets in land,sea,air
expect to produce 300 units in the next 15 years
 
Dreamfighter said:
Avimimus said:
XaHyMaH said:
VTOLicious said:
A Pelikan Tail is actually different:
https://www.secretprojects.co.uk/threads/boeing-jast-jsf-x-32-projects.2121/post-18031
Click to expand...
Aerodynamically it's the same - a combination of horizontal and slanted control surfaces.
Click to expand...

Except that it probably isn't - since the elevons can deflect independently. That said, I can definitely see the analogy.
Click to expand...

I consider a true 'Pelican Tail' e.g. the one on YF-23, and the one now flying on Boeing´s ATS. Those are slanted more to the horizontal plane, the angle is about 45°.
Click to expand...
Sorry, but the tail of the YF-23 is definitely not a Pelikan Tail. It has nothing to do with the angle. The main difference is how it is hinged. See the pics in the link I provided ;)
 
Just to add my 2p to the whole Checkmate pitch control thing, if you look at the included angle between the tails, it appears to be significantly <90deg so it's not going to be very efficient at controlling the aircraft in pitch. Used collectively, they could be a decent airbrake to reduce ground roll but for pitch control, they're in the 'chocolate fireguard' category. It's a tailless aircraft with twin fins...
 
VTOLicious said:
Dreamfighter said:
Avimimus said:
XaHyMaH said:
VTOLicious said:
A Pelikan Tail is actually different:
https://www.secretprojects.co.uk/threads/boeing-jast-jsf-x-32-projects.2121/post-18031
Click to expand...
Aerodynamically it's the same - a combination of horizontal and slanted control surfaces.
Click to expand...

Except that it probably isn't - since the elevons can deflect independently. That said, I can definitely see the analogy.
Click to expand...

I consider a true 'Pelican Tail' e.g. the one on YF-23, and the one now flying on Boeing´s ATS. Those are slanted more to the horizontal plane, the angle is about 45°.
Click to expand...
Sorry, but the tail of the YF-23 is definitely not a Pelikan Tail. It has nothing to do with the angle. The main difference is how it is hinged. See the pics in the link I provided ;)
Click to expand...

Thanks for the correction!
I mistakenly thought the specific hinging wasn´t a necessary feature to be able to speak of a Pelikan Tail, while the hinging is crucial... :oops:

Is there a specific name for very slanted, full-moving tails like on e.g. YF-23 and Boeing´s ATS (with absence of horizontal stabilizers)? Just 'V-tails'?
 
Maki said:
Dreamfighter said:
Is there a specific name for very slanted tails like on e.g. YF-23 and Boeing´s ATS (with absence of horizontal stabilizers)? Just 'V-tails'?
Click to expand...
I believe the term butterfly tail is used for YF-23.
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I was having Butterfly Tail in the back of my mind, but was afraid I would be wrong again...
 
LMFS said:
Saber said:
Also key to remember the huge amount of work that went into majorly increasing the fuel fraction of the Su-57, such as a gas-based fire suppression system that eliminated foam in the tanks, increasing fuel load by 15 percent for the same volume if I recall correctly.
Click to expand...
I remember speculating about that possibility, but do you have actual quotes or data supporting that?
Click to expand...

Afraid your own conjectures are now being quoted back to you as fact? :D I hate it when that happens :)
 
VTOLicious said:
XaHyMaH said:
VTOLicious said:
Hmm, that aerodynamic layout still puzzles me.

The absence of horizontal tails in combination with those relatively little canted vertical tails is quite unique. I cannot recall any configuration out there with a comaprable wing / control surface layout. Even if those (presumably) split air brakes act as control surfaces as well I cannot imagine they would provide the same pitch control authority as full sized horizontal tails. Would it be viable without thrust vectoring?

Any thoughts?
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Those 'things' will be assisted by V-Tail and whole tail is a https://en.wikipedia.org/wiki/Pelikan_tail
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A Pelikan Tail is actually different:
https://www.secretprojects.co.uk/threads/boeing-jast-jsf-x-32-projects.2121/post-18031

...and let's not forget: Up to date no one officially confirmed that those "things" are indeed control surfaces, airbrakes, a combination of both...?
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As an example, the McAir/Northrop JSF offering had the v-tails at pretty shallow angles (better for pitch performance) plus it had a thrust vectoring nozzle. Controls laws were probably similar to our YF-23. Yaw inputs could have been a mix of splitting the wing trailing edge surfaces, some v-tail deflection and vectored thrust. NGC is really into flight control surface optimization and the control laws of the -23 were complex.
 
LMFS said:
Saber said:
Also key to remember the huge amount of work that went into majorly increasing the fuel fraction of the Su-57, such as a gas-based fire suppression system that eliminated foam in the tanks, increasing fuel load by 15 percent for the same volume if I recall correctly.
Click to expand...
I remember speculating about that possibility, but do you have actual quotes or data supporting that?
Click to expand...

I know for sure that that Su-57 has a inert gas system, but I can't remember where I got the 15 percent figure from, I thought it was from Military Acceptance Part 2 on the Su-57, but they don't mention it there, on the gas system itself. I am sure I heard it in an interview but I have to look more and will edit this post if I find it.

Link to the video, 27 minutes in for Russian speakers, don't think it's been subtitled yet.
View: https://www.youtube.com/watch?v=JJ7V78zz7c0
 
Saber said:
I know for sure that that Su-57 has a inert gas system, but I can't remember where I got the 15 percent figure from, I thought it was from Military Acceptance Part 2 on the Su-57, but they don't mention it there, on the gas system itself. I am sure I heard it in an interview but I have to look more and will edit this post if I find it.

Link to the video, 27 minutes in for Russian speakers, don't think it's been subtitled yet.
Click to expand...
Yes, I saw the video and I can imagine they got a nice extra fuel volume by removing the foam, but I also don't remember seeing any concrete figure. We do know the plane's airframe is chock full with fuel in almost any thinkable space.

BTW, Combat Approved has some of these documentaries in English version:

EDIT: Found a source about ESF (Explosion Suppressant Foam), it seems to reduce just 4% of fuel capacity, so it does not seem to be a big issue, but by the amounts carried by fighter jets it is not insignificant, like 400 kg in a plane carrying 10 t fuel.

https://www.foamengineers.co.uk/explosion-suppressant-foam/
 
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LMFS said:
Yes, I saw the video and I can imagine they got a nice extra fuel volume by removing the foam, but I also don't remember seeing any concrete figure. We do know the plane's airframe is chock full with fuel in almost any thinkable space.
Click to expand...

So the Paralay school of design? :)
 
LMFS said:
Saber said:
I know for sure that that Su-57 has a inert gas system, but I can't remember where I got the 15 percent figure from, I thought it was from Military Acceptance Part 2 on the Su-57, but they don't mention it there, on the gas system itself. I am sure I heard it in an interview but I have to look more and will edit this post if I find it.

Link to the video, 27 minutes in for Russian speakers, don't think it's been subtitled yet.
Click to expand...
Yes, I saw the video and I can imagine they got a nice extra fuel volume by removing the foam, but I also don't remember seeing any concrete figure. We do know the plane's airframe is chock full with fuel in almost any thinkable space.

BTW, Combat Approved has some of these documentaries in English version:

EDIT: Found a source about ESF (Explosion Suppressant Foam), it seems to reduce just 4% of fuel capacity, so it does not seem to be a big issue, but by the amounts carried by fighter jets it is not insignificant, like 400 kg in a plane carrying 10 t fuel.

https://www.foamengineers.co.uk/explosion-suppressant-foam/
Click to expand...

Explosive dampening foam may also limit high-speed flow of fuel like when you go to full after-burners.
Soviets have long used nitrogen or cooled carbon monoxide to limit flammability of ullage (fuel fumes/vapours in tanks).
 
Dreamfighter said:
Maki said:
Dreamfighter said:
Is there a specific name for very slanted tails like on e.g. YF-23 and Boeing´s ATS (with absence of horizontal stabilizers)? Just 'V-tails'?
Click to expand...
I believe the term butterfly tail is used for YF-23.
Click to expand...

I was having Butterfly Tail in the back of my mind, but was afraid I would be wrong again...
Click to expand...
Classic V-tails (e.g. Beechcraft Bonanza) are usually angled at 90 degrees from each other and 45 degrees from the vertical.
During the 1940s and 1950s, many competition sailplanes were built with V-tails. Sailplane pilots primarily wanted to keep tail surfaces above weeds during "out" landings. This was before T-tails became fashionable.
Since airplanes often need more vertical stabilizer than horizontal, a few V-tails (e.g. Monnet kitplanes) sometimes add a small vertical rudder below the regular angled fins.
OTOH Predator drones hang both sides of the V-tail and an extra vertical fin all below the fuselage.
Pazmany reminds us that V-tails do not save any of the tail-volume, so V-tails tend to be higher and broader than more conventional tails (e.g. cruxiform).
Dozens of V-tails were designed before electronic flight stabilization was ever invented. Control mixers are also comparatively easy to design. (see Davis DA-2A). One Soviet disco-plane used only control cables to "mix" rudder and stick inputs.
 
overscan (PaulMM) said:
Jackonicko said:
Have we seen a close up photo of the 'Checkmate' logo on the nose?
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You can grab the "The Checkmate" logo with the knight chess piece in the H out of their website in vector format, but the shield logo, not seen that.
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Good spot, but how bizarre to have a logo like that and not plaster it everywhere!
 
Jackonicko said:
Willythekid said:
Jackonicko said:
Have we seen a close up photo of the 'Checkmate' logo on the nose?
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These images are the best I could find!
Click to expand...
I couldn't find anything that let you read the script below (in grey) or see the detail of the logo.....
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I have some pics I can't share where you can read the small text below, if I recall correctly it says "Turn the Chessboard". The logo has the knight chess piece at the bottom, and at the top a silhouette view of the Checkmate fighter from rear below chasing another fighter silhouette which was too small for me to identify but logically, probably an F-35?
 
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overscan (PaulMM) said:
Jackonicko said:
Willythekid said:
Jackonicko said:
Have we seen a close up photo of the 'Checkmate' logo on the nose?
Click to expand...
These images are the best I could find!
Click to expand...
I couldn't find anything that let you read the script below (in grey) or see the detail of the logo.....
Click to expand...
I have some pics I can't share where you can read the small text below, if I recall correctly it says "Turn the Chessboard". The logo has the knight chess piece at the bottom, and at the top a silhouette view of the Checkmate fighter from rear below chasing another fighter silhouette which was too small for me to identify but logically, probably an F-35?
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Ah go on - why not share just a cropped piece of the pictures? In B&W if you like. Watermarked.
 
The use of the same control surfaces and wings as the Su-57 is rather interesting.

Speaking which, I've noticed that the edges of the Su-57's wings (and the LERX/LEVCONs) are considerably more blunt compared to the F-22 and F-35 edges. Why is that? I'd expect that the main benefit would be at subsonic speeds.
 
Jackonicko said:
overscan (PaulMM) said:
Jackonicko said:
Willythekid said:
Jackonicko said:
Have we seen a close up photo of the 'Checkmate' logo on the nose?
Click to expand...
These images are the best I could find!
Click to expand...
I couldn't find anything that let you read the script below (in grey) or see the detail of the logo.....
Click to expand...
I have some pics I can't share where you can read the small text below, if I recall correctly it says "Turn the Chessboard". The logo has the knight chess piece at the bottom, and at the top a silhouette view of the Checkmate fighter from rear below chasing another fighter silhouette which was too small for me to identify but logically, probably an F-35?
Click to expand...
Ah go on - why not share just a cropped piece of the pictures? In B&W if you like. Watermarked.
Click to expand...
See private message. Its TURN THE CHESSBOARD in caps. In font Roboto Regular perhaps.
 

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