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How much of a difference if you put canards on the F-22?

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posted on Nov, 26 2007 @ 12:56 PM
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Increase maneuverability or not much of a difference? Decrease in stealth with more RCS (don't know how much canards give)? Disadvantages and advantages?




posted on Nov, 26 2007 @ 01:03 PM
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reply to post by deltaboy
 


From reading the wiki article, the disads seemed to clearly outweigh what appeared to me to be only slight advantages. America makes better planes than anyone else, and I think there's a good reason we've never been much into canards.

en.wikipedia.org...



posted on Nov, 26 2007 @ 01:26 PM
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Two reasons not too.

You cannot simply add them on to an existing airframe without basically re-engineering the a/c. Also the vectored thrust of the F-22 already does huge part of what the canards do.

Stealth. It may be hard to design a stealthy, functional canard. Also adding it to the F-22 would and could effect its RCS in a bad way unless designed in from the beginning.



posted on Nov, 26 2007 @ 01:35 PM
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reply to post by FredT
 


Lets say we go back to when the F-22 was still in concept, should the canards still be applied? After all the Russians put canards on the Flanker that has vector thrust on them. Unless the canards on the Flankers are for decoration or coolness.



posted on Nov, 26 2007 @ 01:56 PM
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Originally posted by deltaboy
Increase maneuverability or not much of a difference?


Sticking them on now?

Alot of difference and none of it good. You'd screw up structures, aerodynamics and observables in one fell swoop.



posted on Nov, 26 2007 @ 01:58 PM
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reply to post by deltaboy
 


I may be wrong, but I thought the vectored thrust was added after?



posted on Nov, 26 2007 @ 02:23 PM
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reply to post by FredT
 


I believe Fred is correct the use of canards for increased manuverbility was the first step byt the russians followed by TVC. Its interesting the use of both on a plateform since they are both suppose to increase manuverbility is it over kill? is it that both aren't working to there full potential? I don't want to say its either as I respect alot of peoples love of the designs but I have less understanding as to why certian choices where made as I do with western aircraft.


Added somedates to help people visualize if you find anything wrong please let me know.

Mig-29: first flight October 6 1977 (no TVC or Canards)
Mig-29 OVT: pre-built MiG-29M before 1991, later received thrust-vectoring engine and fly-by-wire technology. (has TVC no Canards)
Su-27: Maiden flight 1977 May 20th (no TVC or Canards)
Su-30: 31 December 1989 (Testbed fighter with canards added later in testing)
Su-30M2: December 1989 (upgraded Su-30MK has Canards and TVC)
Su-30MKI:Maiden flight 1997 july 1st(Can have TVC or canards depending on customer)
Su-35:Maiden flight May 1988 (both TVC and Canards)
Mig-34: Maiden flight 2007 (Can be TVC no Canards)

[edit on 22/08/06 by Canada_EH]

[edit on 22/08/06 by Canada_EH]



posted on Nov, 26 2007 @ 02:36 PM
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reply to post by FredT
 


Yet, even with the thrust vector added, they have not taken down the canards afterwards. For example the Indian SU30MKI.



posted on Nov, 26 2007 @ 02:50 PM
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reply to post by deltaboy
 


The Su-30MKI to my knowledge has 2D TVC control.

Su-30MKI becomes the worlds first TVC equipped operational fighter aircraft. According to Jane's all the World's Aircraft, India has the option to upgrade the engine with AL-31FP, which employs fuel manipulation to provide a 3D TVC, resulting in greater maneuverability.



posted on Nov, 26 2007 @ 04:44 PM
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The effectiveness of canards is also dependant on their size and position.

The Flanker has extremely tny canards that are mounted right on the leading edge of the wing, therefore adding TVC would have made a big difference.

The next stage is the Rafale, although they are bigger (relative to the rest of the airframe) than on the Flanker they are also mounted right on the leading edge.

The 'bravest' way to use canards is the the Typhoon way. Much larger in area they are also mounted well forward of the wing which greatly increases the moment arm and minimises the effects of downwash on the inner main wing. The Typhoon is the only fighter to use this form as the Rafale, Flanker, J-10, Gripen et al use the safer, less destabilising 'close coupled' arrangement. Computer testing is said to demonstrate that adding TVC to the Typhoon would not enhance agility, despite test engines have been bench run already.

Regarding the F-22? No, adding canards would do nothing but harm, as soon as TVC was factored into the design canards were no longer necessary and were dropped (early Lockheed designs had them).



posted on Nov, 26 2007 @ 04:50 PM
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reply to post by Jim_Kraken
 





I think there's a good reason we've never been much into canards.



Yes there is, its called timing. Relaxed static stability and FBW were not mature enough to be considered for the teen series so no canards there, when this tech had matured America flew several test vehicles (HiMat, X-31 etc) but the teen series were still new and so there was no fighter programme to incorporate it into (yes, the F-15ACTIVE could have presaged the Super Flanker but this opportunity was missed), When ATF gathered momentum towards becoming the F-22 TVC technology was opening new and different possibilities so it was this that was used instead.

Europe on the hand had only just caught the back end of the VG era with the Tornado and Europes new fighter programmes appeared right in the middle of the canards ascendancy, hence they all have them. Had there been a US fighter programme between the F-20 and F-22 it would have had them too.

Oh it did, the F-21 Kfir



posted on Nov, 26 2007 @ 11:34 PM
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Originally posted by FredT
reply to post by deltaboy
 

I may be wrong, but I thought the vectored thrust was added after?


No, you are not wrong, this point you're clear more than others, because you can get more informations others can't.


For post-stall, I believe vector thrust was designed to fit on F-22 since the program begining, I suspect strongly is because of rate of plan, the design of F-22 is lacking transversal thrust. This is a keypoint I much worried about F-22 was dragged in dogfight?


Back to the thread, what I thought is canard maybe not the best option for supersonic maneuver.



posted on Nov, 27 2007 @ 12:29 AM
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F-22 is already one of the most maneuverable fighters out there, any canard use would have minimal improvements in real world effectiveness, while adding weight, complexity, drag, and cross section to the airframe.

That's why early concepts originally had canards which were there after dropped.

They are not needed.

[edit on 27/11/07 by JimmyCarterIsSmarter]



posted on Nov, 27 2007 @ 02:54 AM
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reply to post by JimmyCarterIsSmarter
 


Depends how the feature is used. If we are simply talking about adding canards to the aircraft as it is now then yes, of course you are correct.

However the early concepts you mention had a canard instead of a tailplane, not as well as, and therefore would not have been any heavier or more complex. Neither would they be draggier or add any cross section as, on the whole, canards are smaller and lighter than an equivalent tailplane design. As I mentioned earlier, it was the advent of TVC that rendered them unnecessary.

This was actually a very timely get-out for American officialdom. Witness the famous quote from a senior US general that "the best place for canards is on your enemy's plane"- clearly an open minded chap, this official bias manifested itself in official DoD and USAF policy where there was odd tendency towards conservatism in aircraft design while at the same time demanding the very latest technology, not through any aerodynamic advantage that a tailplane might have. Through various research aircraft the US aerospace industry was (and is) perfectly aware of the advantages that unusual configurations can bestow. Back in the 1980's a Lockheed engineer in an interview for Flight magazine enthusiastically reported that the advances in RSS and FBW meant that designers were no longer constrained in fighter design as they had in the past.

This was the time when the 'eurocanards' were developed, the USA too had some adventurous designs (YF-23 and X-32 are just two examples that, while not canards, explored the possibilities now afforded). How ironic then that the fighter actually selected for manufacture follow the same aerodynamic formula as the F-15 and F-18 that went before them.

The F-22 (and F-35 albeit without TVC which WAS a feature of the X-32)) made those otherwise incompatible requirements possible, giving the USA the most highly developed stealthy aircraft possible which still looked fairly normal, while the more imaginative, and potentially better, alternatives fell by the wayside.



posted on Nov, 28 2007 @ 04:05 AM
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Cheers Waynos.. Good post.

Canda_EH,

The MKI does not have 3D TVC but neither does it have simple 2D TVC that is Raptor-esque and in a plane perpendicular to the horizontal wing plane.

The MKI TVC is a 'virtual 3D' TVC which operates on axes(one for each exhaust nozzle and independant of the other) that is offset from the vertical tail plane by 30+ Degrees on either side.
Asynchronous movement of nozzles on these axes results in a variety of forces applied on the airframe (including a yaw coefficient of thrust)that are not possible in conventional 2D TVC.

'True' 3D TVC exists on the MiG-35.

Some MKI pics to illustrate what I am saying:





posted on Nov, 28 2007 @ 04:09 AM
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Originally posted by Canada_EH

The Su-30MKI to my knowledge has 2D TVC control.

Su-30MKI becomes the worlds first TVC equipped operational fighter aircraft. According to Jane's all the World's Aircraft, India has the option to upgrade the engine with AL-31FP, which employs fuel manipulation to provide a 3D TVC, resulting in greater maneuverability.


The MKIs in the IAF DO have the AL-31FP, but this is still not 'pure' 3D TVC as I've mentioend above.



posted on Nov, 28 2007 @ 04:52 AM
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reply to post by Canada_EH
 


Its the MiG-35 (the SU-34 `Fullback` is a strike package ala F-15E and Tornado)

and at present - as offered to India , has neither TVC nor Canards (but has AESA)

www.defense-update.com...



posted on Nov, 29 2007 @ 09:18 AM
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You could make the case that with a negative static margin, center of gravity behind the center of pressure, lift, it already has canards - they're just really big ones in the middle of the airplane. The tail lifts most if not all of the time. As you've noticed in the F-22 airshow demo vids, control power isn't much of an issue.

Previous comments on RCS and drag are correct. An airframe with this aero performance and signature has to be developed from a clean sheet of paper to get where it is.

WW



posted on Dec, 15 2007 @ 07:55 AM
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Originally posted by Canada_EH
reply to post by deltaboy
 


The Su-30MKI to my knowledge has 2D TVC control.

Su-30MKI becomes the worlds first TVC equipped operational fighter aircraft. According to Jane's all the World's Aircraft, India has the option to upgrade the engine with AL-31FP, which employs fuel manipulation to provide a 3D TVC, resulting in greater maneuverability.


Seems the images my my previous post were timebound!


Anyways this video gives agood example of the asymmetric TVC of the AL-31FP on the MKI:



[edit on 15-12-2007 by Daedalus3]



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