The problem with the canard at high AoA – even if angled like a LERX – is that its geometry – its sweep angle – prohibits the same level of low pressure generation over the top of the wing as a fixed LERX. The difference however isn’t that significant and probably only results in a fairly slight advantage for the LERX designs at high AoA. E.g a 30+ sustained AoA performance from the Eurocanards vs. a 40+ sustained AoA for fighters like the F/A-18E/F or the old Su-35 – the airshow beauty in the 90s.

Aah yes, but if my memory is right, this topic is not for comparing LERX and canards but canards with tail layout.

Point being, in a turning fight, a pursuing Hornet is better able to point its nose at a target than a Rafale or EF.

Please prove what you said above

You guys bring up the notion that canards are just as good as LERXs/slats at laminar airflow management, even though the numbers clearly don’t bear that out. And then you proceed to trot out strawman arguments in an effort to bolster your case. Of course higher alphas means higher bleed rates, but the point here is how much alpha you can sustain before stalling. Again, hi-alpha ability is a clear indicator of airflow management and stall resistance. And in this area eurocanards are INFERIOR to modern wing-tails.

Conversely, no theory told us LERX will lead a better AoA capability to aircraft.

Going by the replies so far, not even you pro-canard guys seem to agree on this lift/downforce/”stabilizing”/(whatever) thing. So you might want to resolve the issue amongst yourselves before taking on the “opposition.”

Don’t/can’t understand what you want to say, and never be aware anything meaningless.

Please! Given how aerodynamically dirty even a “clean” Tiffy* is compared to an F-22, I’d steer clear of any “draggy” points of contention:
*As an example.

Besides, another thing that “often gets overlooked” is that TVC can be used to trim the aircraft. That means very little, or no surface deflections.

So, indirectly, you proved that most advantage F-22 did in AoA was contributed by TVC.:diablo:

The point is that from an aerodynamics point of view, canard-deltas offer no advantages over wing-tails, and that they are at a dinsinct DISadvantage RCS-wise.
Exactly. Thing is, canards (like VG wings) are a BAD solution if you want to minimize RCS.
Maybe because they learned years ago that any wave-drag advantage attibutable to deltas is only relevant at speeds greater than ~Mach 2–speeds fighters rarely ever see. Deltas made sense on SR-71s and Concordes, not so much on fighters.

Are you nuts?
Because unstable means CoL is set ahead of CoG, so in subsonic flght, horizontal tail will be deflected up which also bring a lift to a/c, that’s your favor, and canards under this condition is forced downward, which you are gloating. But along of speed increasing to transonic, the CoL will move backward. For trimming this move, canard, which previously deflected downward will reduce its negative lift, however that horizontal tail has to revert its lift to none.
Put all things in same comparable condition but wing design, we can see that delta wing layout would gain a significant advantage of wing load and primary lift. Simply, while tail layout is losing its positive lift during transonic and supersonic, canards layout is losing its negative lift.
Furthermore, if both tail a/c and canards a/c tends to be up their nose or come into AoA, horizontal tail must deflect down to bring a negative lift to a/c whereas canards contributs a positive lift to a/c. This Is Why We Say And Most Classical Literature Teach You:”CANARDS GIVES MORE FREEDOM”.

The F-15’s stabs “stabilize” it in the sense that they keep the nose up for level flight.

The point is not how the control surfaces INITIAITE the pitching moment, it’s what happens with those surfaces AFTERWARDS. Your pic talks of canards that “STABILIZED the AoA”… “STABILIZE the pitch rate”… “BALANCE the aircraft”… All clever metaphors that tell the same tale: the canards are applying DOWNFORCE to prevent the nose from departing.

In a tight, sustained turn (or vertical loop), canards must apply downforce to prevent over-pitching–THAT’s the so-called “stabilizing” effect. With an unstable wing-tail, that same stabilizing effect is accomplished by the stabs producing UPLIFT to keep the nose down… And since lift is the centripetal force that holds an aircraft in tight turns, more lift=GOOD.

Wrong! As I said both AoA and upward pitch angle present in high G turn, canards must deflect towards down. An increasing AoA in turn maneuver means the radius of turn could be decreased more, of course, too big AoA to increasing the rate of turn angle leading a down defected canards is needed but this down deflected canard is not a negative lift. please review the picture posted by Robban.

Yes, apparently, the taileron deflecting upwards gives more lift to F-22 in turn maneuver, but thus also means AoA in F-22’s turn comparably smaller than canards a/c in same else condition in which, if F-22 wants approach same rate of turn angle, it must gets faster speed, but turn radius will be enlarged significantly, so please notice starting a turn the TVC on F-22 is deflect upward to making negative lift which you deliberately neglected and your static picture no show.

On the contrary, canards could be deflected upwards or levelly if there is no excessive AoA following which may cause lift loosing. A TVc with the a/c will deflect down to make a lift trimming the over AoA at the turn starting.

Meanwhile, an upward taileron also make a downward force at nose, this also be ignored by us.

LERX’s provide fixed, controlled vortice management at high AoA, which is more than can be said of movable canards. What’s the AoA limit of the Rafale compared to the SHornet’s?

This is depends on AoA, while in a slight AoA, canards gives more lift than LERX.

Then tell me why in almost all the euro-canard pics I’ve seen of them maneuvering hard or cruising level, the canards are slightly canted downwards.

Because of they are unstable a/c, which CoL in front of CoG. Consider in a High G turn, not only upward pitch angle but also AoA occur ongoing, so the canards must deflect downwards to balance the continuously increased upward angle.

Interesting, how different between YF-22 and F-22A?

There is nothing I want to say but this video you guys should watch
http://www.youtube.com/watch?v=VLz2EQm3rrg
Please pay attention to 0030~0035, only 5s the nose direction of the Rafale has changed 180degress.

That delta shadow right side in your second pic I think is inlet of spill door you wanted.
Otherwise, there is more accurate pic available now for estimate length of PAKFA

According to this multi-layer picture, that length Paralay estimated is more close to fact.
The length will be 20.3~20.4 meters.

That Raptor is built worse than a freaking Il-2!

These sour grapes aren’t able to cover that PAKFA does use more advanced techs than F-22, after all there is 20years passed.