"Advances in aerodynamics have made the swing-wing obsolete"

[Basil]

Can the very thick wing root sections of the swing-wing B-1 and Tu 160, which extend to the swivel bearing, be regarded as supercritical airfoil section? If yes, you have examples of a supersonic application.

 

[Scott Kenny]

Can the very thick wing root sections of the swing-wing B-1 and Tu 160, which extend to the swivel bearing, be regarded as supercritical airfoil section? If yes, you have examples of a supersonic application.

Maybe? I'm not sure they have quite the right shape. A supercritical airfoil isn't just an elliptical leading edge, it's a flat upper surface back a ways.

 

[Colonial-Marine]

I was recently doing some reading on the history of the F-111 and the difficulties with the wing carry-through box structure resulting in the cold proof load testing procedure. It got me to thinking if there is any information available on what issues the Soviets encountered during the service of their VG fighters and bombers?

I'd have to presume this is one of those unforeseen types of structural failures where if GD hadn't encountered it first with the F-111 other designer would have when their VG aircraft entered service.

 

[pathology_doc]

Here are a few pics:

View attachment 718088

View attachment 718089

View attachment 718090

View attachment 718091

That thing's wing looks like its mother had a night out with a Handley-Page Victor.

 

[Cannonfodder43]

I was recently doing some reading on the history of the F-111 and the difficulties with the wing carry-through box structure resulting in the cold proof load testing procedure. It got me to thinking if there is any information available on what issues the Soviets encountered during the service of their VG fighters and bombers?

I'd have to presume this is one of those unforeseen types of structural failures where if GD hadn't encountered it first with the F-111 other designer would have when their VG aircraft entered service.

https://twitter.com/x/status/1776649789003682154

View: https://twitter.com/BaA43A3aHY/status/1776649789003682154?s=19

 

[Scott Kenny]

That sounds like a very complicated hinge joint on the Su24...

Anyone got pictures of it?

 

[Kiltonge]

Apparently the F-8 SCW demonstrator was an absolute beast, test pilots had to be told to stop mugging F-14s etc.

It also landed at 200kts, and the 15,000ft Edwards concrete runway was too short for to land there. Maybe VG would have helped...

Supercritical profiles are great for transonic cruise, but aren't a panacea.

 

[Scott Kenny]

It also landed at 200kts, and the 15,000ft Edwards concrete runway was too short for to land there. Maybe VG would have helped...

Supercritical profiles are great for transonic cruise, but aren't a panacea.

They got rid of the variable-incidence part?

 

[F-14ATomcat]

I have constantly encountered this statement, and it always felt iffy to me. Is this actually true? Can anyone actually point to what advancements have reduced the need for swing-wings? I feel like, when we look at famous swing-wing aircraft (F-14, Su-25 Tu-160) we see the same patterns: T/W way less than 1, incredibly broad flight envelope from loitering, to supersonic flight and huge range.

I feel like there's no recently designed aircraft with this set of requirements, modern aircraft tended to mostly designed for either low-to medium speeds (F-35) to medium-to-high ones (F-22).

If you came up to a designer and asked him to design an aircraft today that can do all the same things an F-14 or a Tu-160 can, I doubt they could make one without swing wings. True, modern engines have better T/W than ones in the 70s, but I doubt that alone would compensate.

In life like in aerodynamics, any step in one direction means you lose another direction.

If you choose left you lose right, if you go up you are not going down.

That is the same in aerodynamics, Variable geometry wings are the same, modern aircraft can achiefve STOL with thrust vectoring nozzles, swiveling engines, such as V-22, each and every technology has advantages and disadvantages.

However when designers adopt a technology they need to consider their needs and prioritize what is the best for their aircraft needs.

Variable geometry wings are fine as long as the design really needs it.
Current aircraft do not need them, for example if you compare F-14 a naval fighter versus Rafale M you can see the VG wing on F-14 is maintanance intensive and adds heavy extra weight, canards do not replace VG wing advantages in STOL but if you add very light materials on Rafale the need for VG wing simply disappears since a light airframe can generate enough lift for slow speed landings and short take offs

A straigh wing is the best for lift at low speeds but not the best for high speeds, Deltas are the opposite, so priorities mean, other technological solutions to reduce disadvantages.

the Canard on Rafale adds lift at low speed, while the wing box and pivot of the swiveling wing in F-14 adds weight and since the wing is not fixed is relatively weakly joined to the fuselage, so both systems have disadvantages, but an engineer will decide what other technologies might help to reduce the disadvantages.


Another disadvantage of VG wings is stability due to the center of lift moving as the wing is sweep.
On F-14 they tried to fix it with wing gloves vanes so at the end it is a highly complicated aircraft mechanically speaking, so Rafale is up to some degree a simplier aircraft, and simplicity helps maintainance.


In few words is not only a single technology what matters but a combination of technologies that will decide what technologies an aircraft will use.

 

[F-14ATomcat]

I have constantly encountered this statement, and it always felt iffy to me. Is this actually true? Can anyone actually point to what advancements have reduced the need for swing-wings? I feel like, when we look at famous swing-wing aircraft (F-14, Su-25 Tu-160) we see the same patterns: T/W way less than 1, incredibly broad flight envelope from loitering, to supersonic flight and huge range.

I feel like there's no recently designed aircraft with this set of requirements, modern aircraft tended to mostly designed for either low-to medium speeds (F-35) to medium-to-high ones (F-22).

If you came up to a designer and asked him to design an aircraft today that can do all the same things an F-14 or a Tu-160 can, I doubt they could make one without swing wings. True, modern engines have better T/W than ones in the 70s, but I doubt that alone would compensate.

Aerodynamic studies are always made using some conditions, for example if they compare two canards of different swept, the rest of its features are the same, however when designing an aircraft it is a combination that will decide what set of technologies are needed to be used.

Tu-160 is still in production, the first question is why?
technically B-2 as a stealth machine is far much modern and needed, but Tu-160 is fast, and has cruise missiles good enough to be fire out of the reach of enemy air defences.

The logic of why it is still in production is based upon advantages and disadvantages.
It is a very fast machine, VG wings allow high speed at altitude and low speed landings at the same time.

The F-14 was simply retired because it was expensive to operate, I mean you have a modern aircraft in production with VG wings the Tu-160, simply because still represents a good solution based upon economics and performance.

To say a B-2 is better will depend for what, speed? no, stealth? yes each aircraft has a function, even an agrcultural aircraft has advantages a stealth fighter has not, everything depends for what? for flying very low and slow almost near the ground an agricultural aircraft is better, for evading radar and downing aircraft the stealth fighter is better.

 

[Hanz2k]

Tu-160 is still in production, the first question is why?

Don’t want to disappoint you, but the reason is that Russia is just not able to produce anything more advanced. They never acquire domestic knowledge about large composit structures manufacturing process. Look at famous Su57 wing bolts - this make the picture of the state of Russian airplane design capabilities. They want to go stealth with PAK DA, which based on rumors was B2-esque flying wing design. But it was too much for Russia.

They are trying to play around Tu160 airframe deficiencies with new cruise missiles with 6500km range just to give it some fighting chance.

 

[paralay]

What are the disadvantages of the Tu-160 airframe?

The percentage of materials in the design of the Su-57 airframe:
aluminum alloys - 40.5 - 44.5 %,
titanium alloys - 18.6%,
composites - 22 - 26%.

The percentage of materials in the design of the F-22 airframe:
aluminum alloys - 16 % ( for the prototype - 32 % ),
titanium alloys - 39 % ( 27 % ),
composites - 24% (21 % ).


composite wing of the MS-21 liner

 

[Hanz2k]

- F35 - 35% composites.
- Eurofighter Typhoon - 40% composites.
- A350XWB - 50% composites.
- B2 bomber - around 80% are different forms of composites.

 

[F-14ATomcat]

Don’t want to disappoint you, but the reason is that Russia is just not able to produce anything more advanced. They never acquire domestic knowledge about large composit structures manufacturing process. Look at famous Su57 wing bolts - this make the picture of the state of Russian airplane design capabilities. They want to go stealth with PAK DA, which based on rumors was B2-esque flying wing design. But it was too much for Russia.

They are trying to play around Tu160 airframe deficiencies with new cruise missiles with 6500km range just to give it some fighting chance.

I do not know the state of Russian aerospace to claim if it is behind or ahead.


My point was in an strategic aircraft like Tu-160 VG wings allow advantages in high speed since you can not say B-21 will fly faster or land slower than Tu-160 at the same mass at take off.

In aircraft you can not say more advanced or less advanced based upon such comparasion, aircraft are considered better upon the needs humans give them. Example

Tu-160 is a strategic bomber, you can not use it as a Embraer Preator or a Tucano

To fly low and slow an Embraer Ipanema agricultural aircraft is good for that; to fly fast and high Tu-160 is excellent but for dedicated stealth B-21 is better, if you say we need stealth yes B-21 is better, but for flying fast and with STOL Tu-160 is better, it is the need, not the aircraft it self.

in few words it the purpose what makes an aircraft good or bad

 

[kaiserbill]

Don’t want to disappoint you, but the reason is that Russia is just not able to produce anything more advanced. They never acquire domestic knowledge about large composit structures manufacturing process. Look at famous Su57 wing bolts - this make the picture of the state of Russian airplane design capabilities. They want to go stealth with PAK DA, which based on rumors was B2-esque flying wing design. But it was too much for Russia.

They are trying to play around Tu160 airframe deficiencies with new cruise missiles with 6500km range just to give it some fighting chance.

Incorrect.

https://www.compositesworld.com/articles/large-high-volume-infused-composite-structures-on-the-aerospace-horizon

MS-21 wings below..
The PAK DA isn't "but it was too much for Russia".
The fact is that it is still an active programme, and info on it has gone relatively silent due, like many programmes, to the current geopolitical situation.

 

[F-14ATomcat]

Incorrect.

https://www.compositesworld.com/articles/large-high-volume-infused-composite-structures-on-the-aerospace-horizon

MS-21 wings below..
The PAK DA isn't "but it was too much for Russia".
The fact is that it is still an active programme, and info on it has gone relatively silent due, like many programmes, to the current geopolitical situation.

View attachment 735201

Composites are not new and new aircraft can use them even from countries with relatively not so advanced aerospace technologies.



Oaxaca Aerospace, a Mexican company dedicated to the manufacture of high-speed aircraft for reconnaissance, aerial surveillance and training missions, sought a strategic alliance with the Aeronautical University of Querétaro (UNQ) to materialize the manufacture of a fuselage of composite materials with high performance and low operating costs.

This project was supported by the National Council of Science and Technology (Conacyt) through the “Innovation Stimuli Program” and since 2014 work began on the development of this technological project.

In an emotional ceremony, this first prototype of the carbon fiber fuselage of the Pegasus P400T aircraft, the first of its type made in Mexico and which will serve to generate the first functional carbon fiber prototype delivered to the directors of the Oaxaca Aerospace company.

The student Francisco Daniel Mancera Coyotl, member of the company RHEM composites, mentioned that “for us it is a pride to be involved in this project that stands out for the vision of promoting national aeronautical development and promoting the growth of this sector in the country” he highlighted. .

Oaxaca Aerospace y UNAQ se aliaron

Crean un fuselaje de alto rendimiento y bajo costo

www.eluniversalqueretaro.mx

The sale of the Halcón II was launched, the first aircraft developed 100% in Mexico




The plane:
Aircraft type: Light sport aircraft (LSA)
Capacity: 2 people
Materials: Composite materials (carbon fiber and resins)
Engine: Rotax 915is 141 H

Se lanzó la venta del Halcón II, primer avión desarrollado 100% en México

El pasado sábado 24 de febrero fue una jornada clave para la industria aeronáutica Mexicana en el Aerodromo de Atizapán – Aeropuerto Nacional Jorge Jiménez Cantú, sito en el Municipio de Celaya, estado de Guanajuato, dado que se celebró el lanzamiento a la venta del «Halcón II», plataforma que corre

aviacionline.com

View: https://www.youtube.com/watch?v=-Vs33SWH2JQ&t=52s

I can not believe in Mexico they can build fuselages of composite materials and Russia can not do it, honestly the Russians have much more experience and maybe it is economical factors what makes the program go slow down, but these days composites are well known in countries with a lower technological level

 

[Hanz2k]

Incorrect.

https://www.compositesworld.com/articles/large-high-volume-infused-composite-structures-on-the-aerospace-horizon

MS-21 wings below..
The PAK DA isn't "but it was too much for Russia".
The fact is that it is still an active programme, and info on it has gone relatively silent due, like many programmes, to the current geopolitical situation.

View attachment 735201

Thank you for supporting my case. This article is from 2019. Maiden flight of MC21 with domestic carbon wings was in 2021. Russia is in the point of creating knowledge and industrial base right now, where Boeing and Airbus commercial airframes was minimum 15 years ago and Northrop 50 years ago. Scaled Composites was founded in 1982.

 

[Trident]

Not all composites are created equal, with the MS-21 Russia has indeed leap-frogged Airbus and Boeing manufacturing technology in this regard. While the raw materials (that is to say, resin and fiber) were sourced from established international suppliers initially, that is pretty much irrelevant. Is Boeing's 787 truly (US) "domestic" when they rely heavily on Japanese fiber and manufacturing expertise? The A350, when it likewise uses non-European raw materials? Singling out the MS-21 for that is an intentionally misrepresented comparison (that the necessity of transitioning to domestic raw materials was a massive political own goal is another topic entirely).

What sets it apart is the first large scale use of out-of-autoclave curing on primary structure, something Airbus is still in the process of researching (among other things) as part of the 'Wing of Tomorrow' programme:

https://www.compositesworld.com/articles/update-lower-wing-skin-wing-of-tomorrow

So far from being behind, in important ways Russia's composite wing of 2016 already is Airbus' Wing of Tomorrow!

 

[Nicknick]

Vaccum infusion is indeed a very different process to using prepregs. It allows the highest ratio of fiber to resind and, as I learned from the article above, also a single step manufacturing of big conplex parts.