DutyCat Posted December 1, 2006 Share Posted December 1, 2006 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? Link to post Share on other sites
Dave Fleming Posted December 1, 2006 Share Posted December 1, 2006 (edited) 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 December 1, 2006 by Dave Fleming Link to post Share on other sites
Louis Posted December 1, 2006 Share Posted December 1, 2006 Maybe because they would be called Ducks? Link to post Share on other sites
Aggressor Supporter Posted December 1, 2006 Share Posted December 1, 2006 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." Link to post Share on other sites
kitnut617 Posted December 1, 2006 Share Posted December 1, 2006 (edited) 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 December 1, 2006 by kitnut617 Link to post Share on other sites
doctorpepper Posted December 1, 2006 Share Posted December 1, 2006 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 Link to post Share on other sites
BAM'n'IVM Posted December 1, 2006 Share Posted December 1, 2006 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... Link to post Share on other sites
Michiel Nijkamp Posted December 1, 2006 Share Posted December 1, 2006 (edited) 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 December 1, 2006 by Michiel Nijkamp Link to post Share on other sites
polar911 Posted December 1, 2006 Share Posted December 1, 2006 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 liftas 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. Link to post Share on other sites
Andrew D. the Jolly Rogers guy Posted December 1, 2006 Share Posted December 1, 2006 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." :D Link to post Share on other sites
Cadfael Posted December 1, 2006 Share Posted December 1, 2006 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. Link to post Share on other sites
Chappie Posted December 1, 2006 Share Posted December 1, 2006 Some disadvantages : Poor stealth characteristics. Ding! Ding! Ding! This is probably the main reason why they are not on the F-22 or F-35. Chappie Link to post Share on other sites
ron Posted December 1, 2006 Share Posted December 1, 2006 Canard is a French word. I general Americans don't like the French much so they don't use Canards :D Link to post Share on other sites
Zmey Smirnoff Posted December 1, 2006 Share Posted December 1, 2006 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. Link to post Share on other sites
habu2 Posted December 1, 2006 Share Posted December 1, 2006 Ding! Ding! Ding! This is probably the main reason why they are not on the F-22 or F-35.Chappie Agree. Link to post Share on other sites
habu2 Posted December 1, 2006 Share Posted December 1, 2006 Canard is a French word. I general Americans don't like the French much so they don't use Canards well then I guess "Americans" will have to do without the fuselage, empennage, ailerons, and all those other "French" aircraft parts... :D Link to post Share on other sites
ron Posted December 1, 2006 Share Posted December 1, 2006 well then I guess "Americans" will have to do without the fuselage, empennage, ailerons, and all those other "French" aircraft parts... :D HAAAA, good point!!! Link to post Share on other sites
Zmey Smirnoff Posted December 1, 2006 Share Posted December 1, 2006 well then I guess "Americans" will have to do without the fuselage, empennage, ailerons, and all those other "French" aircraft parts... :D Nice. +1 Link to post Share on other sites
DutyCat Posted December 1, 2006 Author Share Posted December 1, 2006 SU-35 concept? Got a pic? Is that the brown/yellow thrust vectoring one? PAK FA? WHAT is that? Link to post Share on other sites
Col. Posted December 1, 2006 Share Posted December 1, 2006 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 Link to post Share on other sites
Trigger Posted December 1, 2006 Share Posted December 1, 2006 Canard is a French word. I general Americans don't like the French much so they don't use Canards B) LOL, yeah, I'm sure that's it... Link to post Share on other sites
Murph Posted December 1, 2006 Share Posted December 1, 2006 The real reason is to avoid confusing the aircrew about which end is the front B) A-10 pilots have had that trouble for years. B) Regards, Murph Link to post Share on other sites
Skyking Posted December 1, 2006 Share Posted December 1, 2006 (edited) 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 December 1, 2006 by Skyking Link to post Share on other sites
Slartibartfast Posted December 2, 2006 Share Posted December 2, 2006 "Cunard" was a sea-going passenger service. Think Titanic. Canards were tried on the Curtiss XF-55 Ascender of WWII infamy. Bert Rutan really likes 'em. Link to post Share on other sites
Zmey Smirnoff Posted December 2, 2006 Share Posted December 2, 2006 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 Link to post Share on other sites
Recommended Posts