For the yaw, the cobra may not transform into yawing movement but i can tell you from a sukhoi 27 pilot that to hold it, and not departing in yaw you have to pull dyssymetric thrust inputs.

During the Cobra manuever the Su-27 is achieving pitch rate above 70deg/s, do you really believe the pilot is able to apply asymetric thrust settings to deal with possible yaw/roll? Where is this information coming from? No, if yaw occurs it`s done with the rudder as I said, then the pilot add symmetric thrust/afterburner during the recovery to return to the horizontal level. Remember, the aircraft leaves the maneuver deep below the stall speed!!

To me, the fact the F-22 retains more control on aero surface is due to its aeros that are one generation ahead, added to the FBW…..

To me, putting the horizontal tail surface in to the main wing wake is not a generation ahead when it comes to thinking about aircraft design. The F-22 aircraft simply needs big tails to be able to pitch-up those big wings, so it is like talking apples and oranges when stating that therefore “it retains more control”.

the F-22 is a next gen plane, with new FBW, great T/W and TVC and of course…great aeros (vortex generators integrated in the airframe all along the plane).

Well, it depends upon one’s point of view.

There’s so many things wrong with this statement

When I realize that it`s comming from a guy who claims the wing with the LE sweep of 42deg to be a delta wing, the one equalizing the Cobra maneuver performed by the Su-27 with a propeller R/C aircraft kit, the one claiming the F-22 aerodynamics having an advantage in a 3D dimensional wing flow, then many thanks for your contribution making my day.:cool:

That’s not a “limiter”…it’s just an “indicator”

I should have changed that before, but I left it, hoping that some nit-picker shows-up and starts argue about the slightest thing.

So, it can have a flight path going backwards….pretty much only by gravity, not by TVC.

When picking-up my words you overlooked that I`m talking the KULBIT maneuver (in case of F-22 a tiny loop) and not about the backward aircraft motion only. So, according to you the KULBIT manuever is caused by the aicraft GRAVITY? Geez, where did you get your physics degree from?:rolleyes:

What is at “zero speeds”?, Zero speeds only happens with two cases, hanging vertically in the air and sitting on the ground.

Widely used “jargon” when discussing thrust vector control laws describing low speeds (near to zero, zero speeds or negative speeds) when conventional flight control surfaces are ineffective (high AOA, wake from main wing, stall region). I think you knew that already, or not….??

How can one “win” arguments with generalities?

I`m not going on this forum to “WIN”, but to discuss things, learn something new or to share my knowledge I`ve gained with others and I`m sure that almost everyone writing here is feeling the same.

Earlier Cobra manuevers shows extreme yaw while pitching, that is UNWANTED (i’ve never heard any Cobra manuevers where the pilot stated he/she wants to add a little bit of yaw to make it interesting …no the aircraft departed in the yaw axis but the momentum due to pitch down carried it back). Later Cobras also show some yaw, but not as bad, demonstrating either the improved skill of the pilot doing this manuever or improved FCS.

Because you never heard of something before, doesnt mean it doesnt exist. I see that someone has to teach you about these things. At first, some words to the extreme yaw in “earlier and later” Cobra manuevers. I would like to see a video which proves it, bcs no one ever noticed that!! 😮
Since the Cobra maneuver appeared for the first time in Paris Lebourget 1989, no aircraft (non-TVC) ever demonstrated that manuever at such low altitudes and with such high lateral stability without any nose-slice tendencies as the Su-27 (except Su-3X).
BE AWARE: I`m not saying that other aircrafts can`t perform Cobra, they surely can but unfortunately their electronic FCS limiters prevent it due to one reason. Their pitch-up/pitch down motions are affected with serious lateral stability problems caused by assymetric flow separation from the forebody/strakes.
The high lateral stability margin of the Su-27 is comming from its two big fins, two fold-down ventral fins, two “huge” lateral strakes producing nearly steady vortex structure in a wide range of angles of attack and by two small chines on the radome which have a possitive influence on separation assymetries on the forebody and high AOA stability. These all aerodynamics features simply overpower any yawing moment tendencies created on the Su-27 forebody and also the gyroscopic momentum caused by the AL-31 engines unless pilot wanted to do so (rudder/hor.stabs inputs).
Opposite to the Su-27, the Mig-29 does show a little yawing during a Cobra manuever when not performed well by the pilot. Even if the Mig-29 features almost everything as the Su-27, one can say it`s a smaller edition of the Su-27, thus smaller lateral stability margin. In the post-stall region at speeds “near-zero” the gyroscopic effect of two RD-33 prevails, the pilot has to kick right rudder during a cobra to minimize the yaw momentum.

….that is UNWANTED (i’ve never heard any Cobra manuevers where the pilot stated he/she wants to add a little bit of yaw to make it interesting

This is so obvious that I wonder why have you not figured it out yet?.
AIRSHOW SAFETY REGULATIONS!! When performing on airshows at altitude of 200 meters, then YAW is UNWANTED because there is only 200 meters altitude to recover!!. But when flying at 1km or higher during a training/combat mission?? During the Cobra pitch-up motion the aircraft flight path is still controllable with horizontal stabs (differential deflections) and rudder inputs. Actually you can make pretty “kinky moves” with the old Mig-29A like the SU-30MKI does with easy with help of the TVC. The reason? You can lock two targets in a direction which differs from yours by 150-160 degres within 2-4 seconds. The vectored Su-30MKI is performing that kind of maneuver very often!!. You complaining about the energy loss? It is not the factor the pilot should be afraid of, because in a few second you can accelerate straight down (therefore the altitude factor!!) very quickly giving the enemy behind you less chance to follow.
BE AWARE: I`m not arguing about effectiveness of post-stall manuevers, I`m just pointing out what can be mastered with a regular Mig-29A in a post-stall regime. In general, post-stall maneuvers usually demand a very skilled pilot. Remember, you do not need to tell me about the Cobra maneuver, you do not have a clue who you are talking to.

A good question is to ask them to hold it there. Tailslides are actually pretty easy to do for a short period of time, so the measure for these is not if you can do it, but how long can you hold it there before the FCS can’t handle the balance and departs. Notice the movement of the tail-surfaces even though someone here claims it’s all TVC all the time. It’s a misconception that after stall, a winged surface looses all lift. No, after stall, the increase of lift against AoA isn’t linearly increasing anymore, but it’s almost never zero…

Please, do not mix the TAIL SLIDE with KULBIT or COBRA maneuvers together, then it`s hard to decipher what are you talking about. Now, I`m going to tell you something what may come as a shock to you, bcs it seems you never had the chance to see a tail-slide manuever, except at an airshow. The tailslide can be demonstrated longer than usual, all the pilot of a regular Mig-29 needs is a few times to practice the balance and to know the direction and strenght of the cross-wind and elementary knowledge of Newton physics, where…..
F(engine thrust)=m(aicraft weight) x g(gravity acceleration), what means the TWR equals UNIT!!. 😉 When the aircraft slide backwards toward the ground at some “negative” speed, the horizontal stabs add momentum to level the plane.
No doubt, when you have TVC nozzles on your a$$ coupled with the digital FBW, then ballancing the Tail-slide is much easier. In case of the F-22, you see tail-surfaces movements because the FCS is cross-coupled with the TVC control!!. The TVC has the major control authority, remember NO SPEED=NO FLOW=NO AUTHORITY.

It’s a misconception that after stall, a winged surface looses all lift. No, after stall, the increase of lift against AoA isn’t linearly increasing anymore, but it’s almost never zero…

please ,enlighten me how is the main wing producing lift during the TAIL SLIDE maneuver?:confused:

Russians are good aerodynamicists, but in my book the Brits are actually the best…too bad they really don’t have the political will and means…

Brits?? they are the worst when looking at their creations during past 50 years, they simply do not have enough know-how to be.

Best regards
Martinez

P.S: I recommend to read some AIAA papers at first….just the first page is available, you have to pay for the article.

What makes the Cobra maneuver possible?
http://pdf.aiaa.org/preview/1993/PV1993_183.pdf
Unsteady aerodynamics of combat aircraft maneuvers
http://pdf.aiaa.org/preview/1997/PV1997_3647.pdf
Estimation of aircraft models in Cobra maneuvers through dynamic inversion
http://pdf.aiaa.org/preview/1994/PV1994_3494.pdf
The Cobra maneuver as a minimum time problem
http://pdf.aiaa.org/preview/1997/PV1997_3586.pdf
Problems of Manoeuvring at Post-Critical Angles of Attack
http://pdf.aiaa.org/preview/CDReadyMASM03_582/PV2003_395.pdf
High-Alpha Flight Maneuverability Enhancement of a Twin Engine Fighter-Bomber Aircraft for Air Combat Superiority Using Thrust-Vectoring Control
http://pdf.aiaa.org/preview/CDReadyMGNC06_1305/PV2006_6056.pdf

He does the kulbit at slow rate compared to SU and mig TVC..wich is in fact a great aerodynamical effect that shows the raptor have great autority on a large part of his AOA enveloppe.
.

Right, back to topic, the RAPTOR did the kulbit….
The TVC gives the authority, the plane is literaly hanging in the air, control surfaces are almost ineffective when slow speed, so I`m not entirely sure what are you talking about. Everything changes with the dynamic pressure, then the TVC losses authority in favour of control surfaces. That`s why the TVC envelope is usually up to 0.6Mach.

You seems to ignore the fact that things had changed from the ’60. …However, from the begining of the ’80 things did change. …Nowadays we are talking about the AMRAAM and the 9X…
Me? No, but USAF yes.

…and that is helping to build selfconfidence, but history has tought us that we do repeat mistakes. The aircraft defence systems, electro-optical and electronic countermeasures, towed decoys, chaff/flares are improving year by year, so your super AMRAAM and the 9X might be as useful as the sidewinders in sixties!!

Do you think that in caase of a war between China and Taiwan with US intervention, you will have the clear skies situation you need for a clear BVR fight?

Me? No, but USAF yes.

:rolleyes: , a proven tactics by the US since Gulf war to bomb everything with cruise missiles and then send their 100million$ air superiority fighters to secure the area. So far, so good for them.

However, as sad it may sound for the Flankerboys, there is not a single operational TVC plane in the Russian AF inventory. The only operational TVC fighters aside the 100 Raptors delivered so far, are the 40 or 45 MKIs, but these are in the Indian AF.
But let me offer you a small consolation. I do agree that the Russian are number one in entertainning crowds at airshows around the globe…

😀 This Raptor fanboy audience has always been funny. Gentlemen, at least bear in mind that if Russians would had unlimited budget resources as US designers they would have now hundreds of stealth Mikoyans MFI or FSW Sukhois flying in the airforce.
Anyway, I like the fact that Russians are still holding the top in many areas even though their designers were flat and paid the development costs from their own pockets.:D That`s really admirable though.

I wonder if put a center fuel tank in mig29 would degrade the lift? I don’t see a center fuel tank in 29 that often.

Answering the topic questions whether the Mig-29 and the Su-27 have the best body lift among fighters? And how the centerline fuel tank in mig29 would degrade the lift?

1. they have.
2.The centerline fuel tank restricts the mig-29 from high g-load maneuvers which is related to angle of attack, therefore aircraft can`t reach its highest Cy. The fuel tank also adds approximately 0.002-0.005 Cx increments within subsonic speed range, thus it decreases the lift drag ratio a bit. I think more critical factor here is the g-load limits when centerline tank attached.
3. Anyway, how often you happen to see a mig-29?

That is simply plain wrong. Removing the engine after every 150 hours, where did you hear that? .

Not wrong, a reality. They simply do it and they do replace parts during these periodic mainetance checks. Of course, you do not need to remove the engine from the aircraft each time. You take off the engine covers and you have pretty easy access to any engine aggregates and systems.

Like I said…I failed to understand it because I don’t swallow crap as faith. I just showed what you said to a GE engineer

I do not know if this was ment for me, but if yes I`d like to know what you showed him, so I can back up my words. thanks