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No Canards on US fighters...


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They added them just because they look really cool! Oooh, that gives me a "what-if" idea. How about a next generation F-106 with a bubble canopy and canards? That might have some possibilities!

F106x.jpg

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i took this straight out of a basic aerodynamics text by Anderson. it's probably too basic then..

More lift is not true. It is definitely not the reason why the are used in a design. There is no short or definite answer to give in why canard are or are not used. It all depends on many design aspects you wish to consider. However, there are two main characteristics why canards are often used. They are able to provide good control performance at low speeds and they won't stall due to turbulent air coming from the main wings in high Angle of Attack (AoA) situations. (When stalled, these control surfaces do not function). One of the JSF concept did use a canard planform by the way. But I'm sure the F-22 and F-35 don't need them, otherwise they would have been there! Stealth probably isn't the issue either. As for the F-22, the thrust vectoring nozzles make up for stalling stabs in very high AoA situations.

Hope this helps.

Michiel

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A-10 pilots have had that trouble for years. :pray:

Regards,

Murph

Murph,

Don't leave the A-6 guys out on this one...and the Tweet falls into this catagory too. The tweet even has those fancy FOD screens on their exhaust.

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Murph,

Don't leave the A-6 guys out on this one...and the Tweet falls into this catagory too. The tweet even has those fancy FOD screens on their exhaust.

Nothing bad shall ever be said about the Mighty Tweet.

:pray: :blink: B) :)

Regards,

Murph

Farewll2a.jpg

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Murph,

Don't leave the A-6 guys out on this one...and the Tweet falls into this catagory too. The tweet even has those fancy FOD screens on their exhaust.

That's why Intruders/Prowlers have the non-retracting IFR probe - so we can tell which end goes first.

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  • 2 weeks later...
Here's an article that describes why the canard delta configuration for the Gripen was chosen. :banana:

http://www.mach-flyg.com/utg80/80jas_uc.html

Now that's a comprehensive anlysis!

It shows how design choices are complex and depend on a huge number of variables.

As others have pointed out, generally speaking there is no A better than B rule in aeronautics (and all other technical fields), unless there is an outstanding, obvious advantage (such as jet engine over piston engine for fighters).

Davide

Edited by davetur
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  • 3 months later...

IMHO the usage of canards is just one of the branches of development of modern aircrafts and it is used just because it is a bit cheaper to get highly manouevreable plane by adding extra piece of metal, carbon fibre or whatever and improve the software operating it than to develop vectored thrust engines (or even buy either technology or the engine itself). Which of the countries can afford to pay for such engines? And, on the other hand, is it so much more efficient and needed in real situations to use the vectored thrust engine than to use the "common" canards comparing it again with the price? There is a lot of other variables that matter like sophisticated self defence systems, advanced all ranges missiles, cooperation with other support systems like AWACS and so on and so on. Even though the planes itself are more and more complicated beings they can hardly take everything on their own. A bit farther from the canards :whistle:

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And, on the other hand, is it so much more efficient and needed in real situations to use the vectored thrust engine than to use the "common" canards comparing it again with the price?

Yes. For an aircraft flying at a very high altitude, thrust vectoring engines provide it with the ability to redirect it's flight path and point it's nose at a target faster than aerodynamic surfaces alone can. Up where the atmosphere's thinner, there's less air for the surfaces to react against so thrust vectoring gives the aircraft's agility an added boost. At lower altitudes where there's more air to chew up, all those control surfaces can do wonders. Throw thrust vectoring into that mix and you have the potential for an aircraft that can perform cartwheels, end-overs, and all sorts of funky tricks (not accounting for intake design, engine thrust, the aircraft's operating weight and if it's carry anything big and bulky under it's wings of course).

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Yes. For an aircraft flying at a very high altitude, thrust vectoring engines provide it with the ability to redirect it's flight path and point it's nose at a target faster than aerodynamic surfaces alone can. Up where the atmosphere's thinner, there's less air for the surfaces to react against so thrust vectoring gives the aircraft's agility an added boost. At lower altitudes where there's more air to chew up, all those control surfaces can do wonders. Throw thrust vectoring into that mix and you have the potential for an aircraft that can perform cartwheels, end-overs, and all sorts of funky tricks (not accounting for intake design, engine thrust, the aircraft's operating weight and if it's carry anything big and bulky under it's wings of course).

Yep, I agree! But still, there is a question of cost/effectivity ratio (or how is it called, english is not my native language so be patient :-) ) which matters. So I think that U.S. and Russian went through the way of vectoring because a) U.S. can afford it b ) Russia can't stand to be behind and they really can do wonders with least sources. The other countries just chose the golden middle path to get as much as possible from Flight Control System software improvement as well as improvement of target acquisition systems and other important matters like advanced weapons. The question might be why to put so much money into vectoring instead of invest them to avionics development? At the end there is no problem to design the aircraft with all the high-end stuff. The only problem is the price and willingness of the buyer to pay the money. For example: I can't imagine that Russians will provide all of their units with Su-37's just because it's too expensive but if India says OK, we are going to buy 30 planes then the events will move on. :cheers: Ok, I'm again too far :D

Edited by Petear
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With the F-22, I'd imagine that since the whole point is to operate from extreme altitudes and high supersonic speeds in concert with stealth to kil the enemy, the thrust vectoring was the logical way to go.

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Seems to me that money spent on thrust vectoring is money well-spent. Once the initial and expensive work is done, it can be designed into any new aircraft for relatively few dollars. It's like area-ruling, LEX's and afterburning. Large step changes in performance that, once developed, needed little further money thrown at it to make it usable on the next aircraft in the pipeline.

Avionics, on the other hand, is obsolete the moment a specification is issued. Electronics development is always a rapidly receding target, a money pit.

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