Butterfly Wings

Both the F-22 Raptor, its competitor the YF-23 Black Widow II, and the F-35 use the same kind of wing, a butterfly symmetrical type that is not found on any other aircraft. What are the characteristics of this design that makes it so special.
Does it have stealthier capabilities, or better manoeuvrability than a conventional wing design?
Thanks



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[edit on 15/3/2006 by Mirthful Me]

It could be shaped like that to either deflect radar beams since it may use RAM Coating or it may be to make it more agile in flight. Remember the
X-29 with reversed wings? look at the YF-23 image, notice the main wings are 'diamond shaped' so it incorporates the reversed wings with conventional sweped back wings.

Must make less wind resistance when pulling up to the sky so thats what makes it highly agile and stable apart from front Canards/VT Nozzles?

This could have been the reason the YF-23 was more advanced than the YF-22 even though Northrop lost the ATF Programme

Not so sure but just some thoughts.

[edit on 14-3-2006 by Browno]

Actually Browno, it would be more UNSTABLE. The shape is extremely unstable, it's one of the reasons why the plane can't fly without FBW systems.

Shattered OUT...

i dont know about the main wings but ive seen a video and on the video the little (rear) wings rotate up and down making the plane more manoverable.

At a guess i would say the reason for the shape of the front wings is that they offer all the advantages of delta wings without any of the disadvantages of delta wings.

Justin

Maybe unstable aircraft may have a good side like quick moves and sick mad stunts

not sure but just some thoughts.

Originally posted by carcharodon
Both the F-22 Raptor, its competitor the YF-23 Black Widow II, and the F-35 use the same kind of wing, a butterfly symmetrical type that is not found on any other aircraft. What are the characteristics of this design that makes it so special.
Does it have stealthier capabilities, or better manoeuvrability than a conventional wing design?
Thanks

I think what you are referring to is really just a by-product of stealthy designs. One way of reducing the RCS of an aircraft is to use few angles as possible so that the radar is perpendicular to the face from as few angles as possible – the result is that aircraft are designed with as few angles as possible. The “facetted stealth” of the F-117 is an obvious example but you see this repeated in on nearly all stealth aircraft right down to the shapes of the panels etc.

I’ve thrown together this collage of stealth designs to show what I mean:
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Note that the illustration is somewhat simplified.

The ultimate stealth shape is therefore the diamond such as the original Lockheed “Hopeless Diamond”:


The diamond wing is therefore the best for stealth but not necessarily aerodynamically. Therefore real stealth aircraft have to employ modified diamond wings – this applies to F-22, F-35 and YF-23. This diamond shape means that the wings are very deep, so by the time you add the tailplane it ends up being very close behind the main wing … hence the butterfly appearance of joined wing/tailplane.

In answer to the question “why do only US aircraft look that way”, the answer is partly that they aren’t the only ones. The EADS MAKO is a good example of a non-US project which uses the same principle, although it doesn’t take angle-repetition as far as the F-22 et al. Other European stealth designs, such as the various UCAV demonstrators, also have the general feature of angle repetition.

Another related contributing factor to the “butterfly” configuration is that both the wing and tailplane are on the same level. This is again to reduce the RCS. Non-stealthy fighters tend to have them on different levels to improve handling, generally with the tailplane lower (Su-27, F-15, F-18 etc). As such having the tailplane on the same level is something of a compromise between aerodynamics and stealth.


[edit on 15-3-2006 by planeman]

[edit on 15-3-2006 by planeman]

Originally posted by Browno
Maybe unstable aircraft may have a good side like quick moves and sick mad stunts

not sure but just some thoughts.

It's not just a maybe, it's a fact, thighly unstable planes are extremely manueverable, along with others things like TVC and Stabilators.

Shattered OUT...

Although all the aircraft mentioned in the original post are unstable designs, the "butterfly" look has nothing to do with whether it is unstable or not.

You have voted planeman for the Way Above Top Secret award. You have two more votes this month.

Great post planeman I really like the picture you put together, really helps illustrate your point

Originally posted by planeman
Although all the aircraft mentioned in the original post are unstable designs, the "butterfly" look has nothing to do with whether it is unstable or not.

The eurofighter is extremely unstable areodinamically but that doesnt have butterfly wings.

Justin

The Eurofighter Typhoon looks outdated for its age, I wish they designed it more like the YF-23 or somthing like it.