Maybe someone can not read English very well. –

“I was asking you precisely if there were MiG-21MFs during the Vietnam War. Now you are willing to admit, it’s AFTER the war.”

There were shown two versions of MiG-21s. One participated in 1972, the other version (pic4), shown as participant by the Vietnamese, was delivered after the war to the VAF.

I don’t understand what the hell are you talking about. MiG-21s in the Vietnam War were PF/PFM/PFV (tropicalized PFM for Vietnam). -MF never took part in the Vietnam War. I’m not talking of -MF or -bis delivered to Vietnam post war.

There are 3 basic J-8 variants, just for easy understanding.
1. The first, two J-8 prototypes, based on a Russian design. Without Russian support it becomes a failure, no radar = smaller inlet for example, missing frontal weight a.s.o.

Wrong. The J-8 prototypes were exactly like the J-8Is. They have no radar because obviously PROTOTYPES DO NOT USE RADAR at an early stage of development. Their nose is much more likely to have telemetric equipment instead.

2. The second, ~ 90 J-8I (modified) which means some changes to the earlier design,
(so far, those pics given show the modified J-8I) more different from Russian design, but still visible and with a small radar now, still a failure.

Wrong. There are 130 J-8I built. No airframe changes. Nearly all of them are still in service with the PLAAF today, some having been turned into reconnaissance—something you do to a plane that can successfully fly very fast, and very high.

Are you shure about your basic knowledge. Empty weight differs from batch to batch.

If your empty weight differs from batch to batch that significantly, you have a major quality and component standardizations problem.

I don’t even think that the Russians are THAT BAD in quailty issues, so I think that statement of yours is a mere excuse.

At least you did not dispute, the MiG-21Fs offer the best wing-load-ratios
The TOW given is: max int. fuel, full gun-load and two K/R-13 AAMs. The pilot and support systems (oxygen a.s.o.) included.

That one is no dispute. But you also forgot to add that the -F model has a low polar mass (CG to back, little weight on the nose), that makes the plane less stable to fly. Planes that are less stable (meaning less inclination to go straight like an arrow) also tend to be more maneuverable, because they have less inertia that keeps the plane flying straight. So yeah, the -F can be a little tricky, the -PF series less so (a bit more balanced design). But as the nose gets heavier, the plane becomes more stable but less eager to maneuver as with the later series. As the plane becomes more stable, it is easier to hold its course at high speeds, hence why supersonic flyers and interceptors must choose highly stable layouts (at least before the age of FBW).

The MiG-19S/J-6 is tricky to fly (difficult as Chinese Korean War ace Han Decai puts it) because the plane got so little weight in the nose. But that also makes it a very good “twitch” fighter.

The data posted are from GDR AF (1992) and MiG (R.A. Belyakov and J. Marmain)
“3000 kg” of internal fuel = 3000:0,78 = 3846 litre

3000kg of internal fuel is a little hard to believe for a plane of this size and weight. An F-16, which carries more internal cavities, is about 3,000kg of internal fuel. So doese a MiG-29.

The Gripen, a plane of slightly larger size and more weight, carries only 2260kg of empty fuel.

~3462 litre/2700 kg was the max intern. for MiG-21MT/Tip96T, but have to be reduced to a flyable ~2950 litre or ~2320 kg internal fuel. (T for toplivo:fuel)

2300kg is more believable.

Let me tell you again, and save you the saliva. There is no YE-152 input. There are notable differences in the in both aircraft—J-8I has a thinner wing cord, has wing fences, little or no spine, smaller inlet, wings that are more sharply angled, and a body that is considerably slender. It defeats the purpose of copying if you are going to make significant changes in the airframe and the plane’s aerodynamic quailties. Even the inlet changes means significant differences on how the airflow into the engines can be calculated, whch also affects the way the “tunnels” inside the jet is designed. The J-8I prototypes, if you looked at photos in one of the Chinese links I gave above, was virtually identical to the serial production.

You seem to think that aircraft production and design can be plug and play. TOTALLY WRONG. An airframe is not like that. They are totally designed like they are, as a whole from nose to tail. Even seemingly small changes can mean total changes in the way stress lines are run throughout the length of an entire aircraft. An airframe is very inflexible—you either copy it exactly, or you have to work the entire thing from scratch.

(For that matter, the only thing the J-8II shares with the J-8I is the designation and the engines—the airframe is totally new).

The J-8I program was already being developed when the CR happened. So again, your theory flopped on this point.

How did the Chinese knew about secret Russian prototypes—they DIDN’T.

And Strevitel, anyone can make a freakin web page and put their opinions on it BUT THAT DOES NOT MAKE IT AUTHORITATIVE.

Other than the inlets and the ventral fin, it is quite foolish and stupid for you to associate the MiG-23 to the J-8II when both have completely different aerodynamic configurations, different engines, different flight regimes, and very DIFFERENT dimensions.

I agrre partially with you the Q-6, J-9 and the J-8 i feel all the programs need the MiG-23 but the only one that succesfully got it is the J-8

No, all the J-9 needed was an enigne. A Spey turbofan would have suffice though an R-27 type engine would also have been convenient.

The J-8II really didn’t need the MIG-23 splitters—they could have easily taken the design off from the Phantom, and there was more than a few crashed examples around. The folding ventral fin was actually unnecessary.

I never said a VG version buit the direct lift MiG-23PD aircraft, the MiG-23PD looks quit simialr to one of the configurations the one of the picture of my previous post that looks like a MiG-23/Mirage III but has a rear MiG-21PD fuselage, i do not think so but one of the configurations was similar to the MiG-23PD to solve the lack of space for a Radar in the MiG-21/J-7 and J-8 programs

And where the hell would China get a MiG-23PD?

East Wind Series: “under Soviet tutelage”

Eh where is the Soviet tutelage in these designs?

http://afwing.com/intro/j8-1.htm

Babelfish:

“In 1958, our country started “the east wind” 107 fighter planes and “the east wind” 113 superfighters voluntarily designs. These two kind of airplanes all have afterwards encountered the midway die young destiny. “The east wind” 107 is the Shenyang airplane design office design supersonic all-weather fighter plane. Its design target is: The maximum speed is speed of sound 1.8 times, 升限 2 myriameter; Installs two engines. This machine started from August, 1958 to design, in May, 1959 invested the trial manufacturing, in June made the significant revision to the original design, in November developed stops, concentrating the strength to carry on “the east wind” 113 airplanes developments. East wind 107 models “The east wind” 113 is the upper air superfighter which a military engineering institute designs. The design target is: The maximum speed is speed of sound 2.5 times, 升限 2.5 myriameter. This machine started in 1958 year’s end to design, 196 □years made part of components. Because design target excessively high, from the material, the end product, the weapon to the engine all is the brand-new development, deficiently inherits the nature, has been separated from the Chinese then industry level, also has been separated from the aviation industry reality, is impossible in the short time to do. The airplane design speed has requested “the thermal barrier”, but domestic at that time to 气动力 warm thermal load question, theoretically all has not solved with the experimental method in, the essential aviation scientific research experiment method has not also constructed. At that time domestic did not have develops this kind of high target fighter plane the technology base and the physical conditions. Therefore, in 1961 could not but stop developing.”

I amnot contradicting my self even if the Saphire does the search and the Appaulete does the tracking that is a weapons system allowing the Saphire-23 weapons system multitarget engagement capability thanks to the additional Apaullete antenna 😀

Listen to me. The Saphire 23 does not have multiple targeting capability. Who do you think dictates the multiple targeting—it is the radar that tracks and locks the target and guides the missiles. It is the Apaulet who has that, not the Saphir 23. The Apaulet is more than just an antenna, it is a seperate fire control system. Without the Apaulet, the MiG-23 cannot do it. And remember, the Apaulet never went into service.

The MiG-21MF itself was not very popular. It was considered heavy, and was quickly superceded by the -bis.
MiG-21MF MiG-21bis
empty 5350 kg 5450 kg
TOW 8200 kg 8726 kg
MTOW 9400 kg 10420 kg

Wing area for both 22,95 qm , ever heard about Wing-load?
The most agile was the F-version, TOW 7370 kg (2xK-13)

Frankly I have seen different versions of the weights. With the MF going as high as 5600kg and the -bis as high as 6000kg. I’m not sure who is right, but your TOW is way too high for your empty weight—no way a MiG-21 can hold 3000kg of fuel internally.