Robban

If you want to compare the Gripen and the Tejas, I am willing to listen to your figures and debate them mathematically. But if you do not want to be dismissed as someone simply repeating marketing blurbs you should state conditions under which such results were observed. Without this your statements about turn rates hold no water.

What figures? The only official turn rate numbers for the Gripen is 20 deg/sec sustained, and 30 deg/sec instantaneous. Nice info when debating on public forums, but not if we are to do serious calculations.There is no way for us to come to any conclusion as to which fighter turns best at what speed altitude or weight. As an example, we don’t know how much lift is being gained by the vortex from the canard when it merges with the vortex of the main wing. As I said, official numbers are good when one wants to slam punches at one another at discussion boards. But they do not tell enough in order to have a serious debate. But enough to have a fun debate.

It is however my firm belief that an unstable canard delta fighter offers more in terms of lift/drag, manouverbility and agility than an unstable delta fighter. I’m not a dictionary. But what I’ve read over the years has led me to this conclusion. I know people wont agree, and that’s ok with me.

I’m not here to make enemies, even though it’s easy to step on somebodys toes. In the end we all learn something.:)

And please, I’m not bashing the LCA. I’m merely defending the Gripen.:D

According to calculations done by the same person who gave you the 17degs/sec figure based on older figures. As newer information is available about the aircraft the numbers change.

What has changed? The LCA lost a ton in weight, increased its wingspan by 1 meter, or what?

And who told you that canard aircraft have to be more unstable?

I meant that an unstable canard equipped aircraft can more safely handle higher degrees of instability. The canard balances the plane in front of the aerodynamic center. The LCA balances with it elevons aft of the aerodynamic center.

And Tejas powerplant will not be the GF404 forever either. There are plenty of upgrades that both aircraft will receive in blocks. And you still cannot underestimate the advantage of lower wing loading and faster roll rates. Those figures don’t change as easily. They come with the design.

Sure, I’m just saying that perhaps you should not use current Gripen TWR with a prototype LCA. When LCA enters service the Gripen will be up to par in this department.

And wingloading isn’t everything. There are many other factors, lift/drag ratio etc. A canard offers alot here. And about roll rates, the Gripen can be programmed to roll at >400 deg/sec, but it’s really not necessarry. 270 deg/sec is quite enough. Seeing as how similar the Gripen and LCA is in this regard, it comes down to roll acceleration. I don’t see any advantages for either plane here.

LCA has the lifting body design too. It is a pretty standard feature on all 4+ generation aircraft.

The Gripen uses wing fuselage blending on the lower fuselage as well, the LCA does not.

Yes that’s all very fine except that canards have enough disadvantages of their own too.

Yes, but an important benefit when it comes to manouvering is that the canard gives off a stable detached leading edge vortex that interferes with the vortex flow from the main wing and which mutually reinforces the vortex strength of each other, and therefore burst at a much higher AOA than a lone delta wing would do.

It is a fighter aircraft. It is meant for maneuvering. You want an aircraft with nice straight sub sonic flight characteristics get a B 747. Tejas is optimized for transonic and supersonic flight where its Lift to Drag ratios are very good. The whole platform and its engine Kaveri were designed for transonic maneuvering and it is good at that.

Yes, but low drag is preferable for all conditions of flight. The canard offers the same benefits as a fixed LEX, but they do not cause unecessarry drag when they aren’t needed at both subsonic and supersonic speeds. For most of their service life fighter planes do fly along in straight lines, and shallow turns.

Obviously you have not seen enough photographs of either aircraft you mentioned above.

I have thousands of Gripen pics. The surface quality of the plane is flawless.

http://img.photobucket.com/albums/v486/robban75/136.jpg

http://img299.imageshack.us/img299/1686/dscn2150ur5.jpg

And Tejas is not just a simple delta. The cranked hybrid compound is a rather innovative design. You really think canards are the holy grail of aircraft design don’t you?

I’d say the LCA wing design is similar tho that of the Viggen. Nothing new really. And no I don’t think that canards are the holy grail of aircraft designs, but they offer much more than you seem to realize.

Where did you get those numbers :confused:

I’m afraid I can’t remember were I originally read/heard those numbers. Searching the net gives similar numbers though. Correct or not I don’t know.

Considering it is a delta with no canards, it most likely has a lower level of instability. Its pitch acceleration and especially ITR should fall behind those of the Gripen, same goes for STR because of higher drag during turns. This is probably even more noticable in the supersonic realm.

Just my opinion, feel free to disagree.

So, when is the F414 equipped Gripen expected to fly? Its my understanding that the fuselage would have to be extensively modified to fit the GE Engine from the Super Hornet.

AFAIK, it will probably fly soon. The fuselage only needed minor modifications to fit the F414.

I wonder why the F-15 Aggressor is carrying two external fuel tanks? Maybe one centerline……….:rolleyes:

Probably because they don’t use kill removal. They have to stay in the fight for as long as possible? They get killed, they exit the fight, and then they re-enter the fight a little later.

Sorry guys, but the F-35 looks like a,,,,