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No Canards on US fighters...


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Except for the good ole USA, It seems that ALL of the recent fighter designs have embraced the concept of canard foreplanes, to wit: Gripen, Lavi/J-10, Rafael, Eurofighter, late SU-series, Mig 1.44 ATF. Am I leaving any out? The American F-22 and F-35, which are more advanced aircraft than all of these (except maybe the Mig) do not have canards. I know we have tested them. Are they or are they not aerodynamically advantageous? Did we leave them off for stealth considerations? Is there American industrial bias against them? Anyone have any thoughts on this?

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The US have missed out the generation of active control unstable aircraft with Canards, jumping from F-15 to F-22 - although they were tested on the F-15.

I would guess that the control software for the F-22/35 is able to offset the control that canards give

Edited by Dave Fleming
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I reason if canards are so good or beneficial, it would have been designed in the F-22 and F-35. Since they are not, and that the U.S. has tested canards on various airplanes in the past, I would imagine they are less beneficial than helpful. Maybe some engineers can give some insights.

I think it was Harry Hillaker, one of the chief designers of the F-16 that said the famous quote: "The optimum position for canards is on somebody else's aircraft."

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I would say that for the majority of aircraft in your list, they're all deltas with cunards. Israel started them off when they fixed cunards onto the Mirage didn't they and found a vast improvement over the regular Mirage. Since then it's been the fad, but on the other hand, the US doesn't have any Deltas anymore which might explain why there's not cunards on US fighters.

Edited by kitnut617
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the reason why canards work well is that on a conventional figter design, the elevators/hort stabs have to generate downwards lift in order to counteract the moment. for canards, since they're in front, they have to generate an upward force. when you look at the total lift, the canards will obviously give you more total lift

as to why they aren't on US jets - only the designers can answer that. probably looks better, anyway

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From looking at canard experiments on F-15 and F-16 test planes, it looks like the canards were mostly used for "supermaneuverability" tests, which the F-22 handles with thrust vectoring.

There are tiny little canards on the B-1B...

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the reason why canards work well is that on a conventional figter design, the elevators/hort stabs have to generate downwards lift in order to counteract the moment. for canards, since they're in front, they have to generate an upward force. when you look at the total lift, the canards will obviously give you more total lift

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

Edited by Michiel Nijkamp
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the reason why canards work well is that on a conventional figter design, the elevators/hort stabs have to generate downwards lift in order to counteract the moment. for canards, since they're in front, they have to generate an upward force. when you look at the total lift, the canards will obviously give you more total lift

as to why they aren't on US jets - only the designers can answer that. probably looks better, anyway

That effect was tough on planes like the f-106, just as you wanted to rotate on take-off your elevators are imparting a downward force, adds to the take roll and speed required.

I believe the fixed canards produced a vortex that increased lift which helped somewhat.

The fly by wire "unstable" aircraft are different in that the center of gravity does not have to be inbetween the center of lift and the moment of control, that reduces the advantage of canards.

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There are tradoffs in any configuration decision. The mission and performance charcateristics drive these decisions, some of which favour the canard, others that favour the tail.

Some advantages :

Increased maneuverability because of increased instability.

Close coupled reduce wing twist.

Reduced trim drag in the supersonic regime.

Some disadvantages :

Possiblity of disturbed flow over the wing.

High lift on canard reduces its efficiency, increasing its efficiency reduces its lift.

Poor stealth characteristics.

Sizing very sensitive.

Small moment arm requiring larger area.

All in all, it is easier to design a bad canard than it is to design a good one.

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New generation of Russian aircraft MiG-29M/K/OVT. Su-30MK2, Su-27SM, SMK and *new* Su-35 concept lack canards as well. It seems canards were a fad while thrust vectoring is here to stay. I'm eargely awaiting the release of PAK FA concept to confirm that theory.

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Canard is a French word. I general Americans don't like the French much so they don't use Canards :cheers:

well then I guess "Americans" will have to do without the fuselage, empennage, ailerons, and all those other "French" aircraft parts... :D

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The real reason is to avoid confusing the aircrew about which end is the front :)

Now if you'll excuse me I'll log off for the night and go hide incase Murph, Waco et al are crossing Scotland with some live rounds :whistle:

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well then I guess "Americans" will have to do without the fuselage, empennage, ailerons, and all those other "French" aircraft parts... B)

We did. It's called the B-2. B)

B)

Mike

Edited by Skyking
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SU-35 concept? Got a pic? Is that the brown/yellow thrust vectoring one?

PAK FA? WHAT is that?

No, not the brown/yellow. Its a relatively new development. Here is the link to Ken Duffey's translation of the related article. It will look something like this Designations of Su-35 and Su-35BM are being used. If the flying prototype has been built - no one saw it yet.

PAK FA is the Russian 5th gen concept. Supposed to be shown to the public 2007-2009

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