The comments below are written by a friend of mine, and he wants to be anonymous. But he knows his stuff, well he has to, it is required in his profession.:)

I am always a little uncomfortable about getting involved in these “which is the better” configuration discussions. The reason is that it is very often a function of the specific design requirements of the aircraft you are designing. Consider this: When Gripen (and many other modern aircraft) was designed, one of the strong candidate configurations was a conventional layout (albeit with a funny location for the engine intake). Now, if teams of aeronautical engineers, some with PhD’s in aerodynamics, decided that it would take some serious study and wind tunnel tests to decide which configuration was better, then maybe the answer isn’t so simple? Sometimes the final choice is dictated by one particular design requirement which the client regards as essential, but that another client may have had no particular interest in – here I am for example thinking of Gripen’s ability to generate a strong download on the nose gear and main gears with the canards and elevons after landing, which combined with a brake in the nose gear allows very strong braking after landing.

About upload and download on the canards, it is not nearly as simple as some posters think. I think I understand why they think a download is required from the canards when unstable – their argument is that a CG behind the main wing aerodynamic centre automatically goes along with a nose-up pitching moment. They forget that you need to split trim requirements and stability requirements – the two are completely different concepts. The trim requirements are functions of the pitching moment of the aircraft as a whole. For example, you can place the CG behind the neutral point of the canard/wing/fuselage combination, which would make the aircraft statically unstable. However, at the same time you could deflect the elevons down (which has no effect on static stability) which would cause a strong downward pitching moment which you would have to counter by deflecting the canards leading edge up. So, the pitching moment of the wing and other control surfaces influence the trim requirements in addition with the current CG location. With short coupled canards like on Gripen, there is also a mutual interference effect that makes the whole situation more complex.

Both the conventional tail and canard configuration, even when highly unstable subsonic, usually go stable when supersonic due to the shift in the wing and canard neutral point when passing through the transonic regime. There are some interesting advantages here when you have a canard, as it is almost unavoidable to require a strong download on a conventional tail but even when supersonic you sit with positive lift on the canard. The advantage here is more related to trim drag and controllability, as well as turn performance in the transonic and low supersonic regime. I think people sometimes think “relaxed stability” or unstable means unstable throughout the flight envelope. Aircraft that are unstable through the entire envelope (subsonic, transonic and supersonic) would require such a high level of instability in the subsonic regime that they would end up with severe controllability issues, unless, of course, they make use of a wing sweep mechanism which has its own practical problems.

You are right that the canard can act like a LERX, and in general you have a littlebit more freedom with canard/elevon combinations to decouple direct force and pitch control from each other. However, there are ways to achieve similar things with conventional configurations, which again brings me back to the fact that the choice of configuration is seldom obvious from the beginning.

You are correct about the lift/drag scheduling. Gripen and other modern canard aircraft makes use of this to minimise drag throughout the envelope and it is very effective.

The videos are not comparable unless they are done at the same speed and height.

The MiG-29 does not bleed energy as you claim, the Gripen is the one that bleeds energy more, why? It starts its turn at 30 deg/s but can not sustain it so it drops to 20 deg/s so now tell me who is bleeding energy, the MiG-29A that starts at 28 deg/s but can not keep the 28 deg/s turn so it drops to a 22deg/s STR?

I’d say the altitude is similar, speed, who knows, close enough I think.

Look at the vids again. Which aircraft starts the turn with a turn rate it can’t sustain, bleeding alot of speed in the process? Hint, it’s not the Gripen.

the test flight video is quite clearly a CGI. How else can one explain the sudden disappearance of the model in flight when the clouds around it are still there ? See the attached screenshot.

It’s not CGI. The clouds visible on both screenshots comes from the next screen. Notice how the clouds have less contrast on the first shot. Also the aircraft is slightly faded as well on the first shot.

It simply is not the cobra, the Cobra is russian not swedish and was made for the first time on a Su-27, and its named in honor of a russian pilot
Very likely it banks because the Drakken experiments lateral stability problems, in order to do it straight you have to have total lateral stability.

It is simply a maneuver made famous by the russians. I bet you there are many aircrafts out there that are able to perform the same maneuver. It’s just so overhyped.

Well the Draken is less advanced aerodynamically speaking, and it doesn´t have FBW. The MiG-29A/C for example is stable, and it also lack FBW. So it´s cobra is “rougher” in comparison to the Su-27´s.
The maneuver done by the Draken in the vid is a rapid pitch up to a very high AoA, with a loss of speed as a result. It may look a little rough, but I fail to see how this is different to a Cobra done by an Su-27.

Draken doing a cobra maneuver @ 1:51. http://www.youtube.com/watch?v=jqiDEcfSnXs&feature=fvsr

in the Viggen book by Flyghistorisk Revy, a Viggen pilot says this maneuver was very much achievable with the Viggen as well. What´s the big deal?