Maybe I am the only person on the planet not knowing this but...

Is there "a reason" why the MIG and Sukhoi fighters seem like complete look-alikes. Compare the Su27 with the MIG 29 and you know what I mean.

Or are these in reality the same designs produced by another factory?

definitely different designs - but things designed to fill the same roll using the same technology tend to wind up looking very similar many times, even if there is no communication between the different designers. After all, both of those aircraft share more or less the same layout with the F-15 even.

Don't worry. I'm also wondering why :-)

Both the Mig-29 and the Su-27 came out because both manufactures came out with a common flight data and also, came out with a common design. So there goes the similaries of the two. The Su-27 has been built for long range intercept, so a bigger airframe and no droptanks while the other one the opposite.

Does a Bf 109 look like a P-51 B to you?

both fighters: inline engine, low wing airframe, similar construction...

but complete different a/c

Same for MiG-29 vs. Su-27

they have 2 engines, LEX, 2 stabilizers, shoulder wing configuration ..

totally different combat spectrum (MiG-29 short range interceptor, Su-27 long range/duration patrol a/c ... similar to Bf 109 vs. Mustang)

compare a Su-27 to a F-15 and you also would find similarities

Just my 2ct.

cheers

Steffen

MiG and Sukhoi are two separate companies. Soviet and Russian aircraft companies design aircraft separately, but consult with Central Aerodynamics and Hydrodynamics Institute (CAHI, TsAGI). CAHI advises the companies on aerodynamic solutions to meet their needs.

David

Steffen has a good point.
I say this in all seriousness--my wife and daughter would not be able to tell the difference between either pair of aircraft. Or between a DR-1 and the Space Shuttle for that matter.

Why do the US armed forces fly F-15s and F-18s? Both are twin engined, twin tailed, intakes on the fuselage sides, aircraft. But there are many differences. Same with MiG-29 and Su-27. (And the Sukhoi is HUGE! For a fighter anyway.)

I can see similarities but I see 2 very different looking aircraft, I personally couldn't call them look-a-likes and certainly not the same design
Mal

Here's a planform comparison. The Su-27 is in the upper left hand corner and the MiG-29 is below it.

Ok, my 2 cents. 1st cent, I absolutely think the SU-27 is a gorgeous plane to look at, I love it. 2nd cent, If you look closely, the F-16 and the Mig-29 sorta, kinda look alike. And to a certain extent, yes, the mig and SU do have some familiar tones to them.

Ok, my 2 cents. 1st cent, I absolutely think the SU-27 is a gorgeous plane to look at, I love it. 2nd cent, If you look closely, the F-16 and the Mig-29 sorta, kinda look alike. And to a certain extent, yes, the mig and SU do have some familiar tones to them.

Throughout the history of aircraft design, there are schools of thought and corporate ideologies that produce similar designs. These are opften a product of the limitations of the technology available. Eventually, a generation of aircraft will evolve to mostly resemble each other until, to gain a revolutionary advantage, someone decides to try something radical, i.e., monoplane VS biplane, fixed gear VS retractable, jet vs prop, straight wing vs swept, etc.

WWII favored (in Europe) low-wing monoplanes with liquid cooled engines--at least for fighters. In WWII Pacific low-wing monoplanes with a radial engine ruled. That difference was mainly a design reflection of technology and logistics.

Nowadays, a variation of the delta wing family is what fighters are designed around, with big canopies to see from, and leading edge body-blending strakes. All of Al's examples have this except the F-14 and F-15. They were 1960's designs. F-16 resembles the MiG and Su only from the top, but in its own way is close to the Sukhoi in the setting of the forward fuselage relative to the intakes.

Right now, all fighter designs will resemble one another to a degree, because the state of the art has determined the most efficent planform for fighters.

That is rather basic an explaination from which I can expand.

Thanks Fred

that is what I meant, but you described it much better than I did!

cheers

Steffen

originally the MiG-29 and the Su-27 had been competitors for the same government tender, but later there were two different specifications issued, and each model had been converted to fit the respective specification (exactly because - while the specifications were originally the same - the two design bureaus had two completely different, but viable concepts). If you look at a Su-27 it is much larger than a MiG, and it is only one main difference.

No, it certainly doesn't!

It's not about, all airplanes look the same because they all have wings. Or, all fighter planes look the same because they all have the same purpose.

It's about "family resemblance".

Compare it with birds. For the uninterested observer every brd is just what it is: a bird. The specialist will have many categories and will talk about families that share certain characteristics and that are members of the same "evolution" family.

The same goes for airplanes.

A good example is the Phantom II. Compare the shape of this plane with the ones made by the same company in earlier times and you will find remarkable similarities. You could say that the Phantom II is a furhter evolution of a design process that started just after world war II.

Its clear that companies (or their R&D divisions) are influenced by what the competition does, it is also clear that they will continue to rely on their own solutions (well known and understood) if at all possible. And its nice, as an airplane freak, to recognise that "this for me unknown plane must be a McDonnel" by recognising characteristics of the thing. Heck, we do the same with musifc, don't we?

Back to the MIG and Sukhoi. Yes, one is bigger than the other, and they have another purpose, but it seems clear from the shape that the developers were basing their design on a common design.

I think that David gives very good information:




And this seems to be the case for a large part of the Sukhoi- MIG stable.

Maybe not so important but being interested in those magnificent flying machines, I just love it.

Hi Drabslab

you misunderstand my post (that is why I posted again below Freds post)

It is all about certain timeframe, with a certain knowlege base and the requirements from the government. Military aircraft are state of the art when they are developed and thus based on the latest knowledge.

Lets say the Soviet government wanted a 2 engine a/c (reliability and additional thrust for take off and climb). OKB Suchoi and OKB Mikojan took the latest info on aerodynamics, materials and ergonomics (beside others) comming from "public" sources. Also they used their own knowledge on former a/c ---> similarity is no wonder and Suchoi a/c were always on the large side while MiG's were the small sports cars nobody fits in

Also as already stated the F-16 looks close in shape to the MiG-29. Compare the wing shapes of all the Generation 4 a/c (MiG-29, Su-27, F-15, F-16) --> they look similar (delta shape with more or less arrowed trailing edge)

The Gen 5 a/c (Typhoon, Rafale, Gripen even the F-22 fits in although it has ailerons and no canards) have similar wing configurations...

I hope I made my point clear.

best wishes

Steffen

Yes, you do and you are right. And this is exactly what I find so interesting in "watching planes". That you start seeing similarities which are not always obvious.

Good information, Steffan.

Interesting trivia about the Soviet system. Consider the planform and designs of MiG-19, MiG-21, Su-7, Su-9 and Su-11. All were nose inducted for the engine. The -19 and the Su-7 had similar pre-delta wings. The -21 and all the Su's had that sewerpipe fuselage, all had delta wings (except the aforementioned Su-7). That had to do with a modular design philosophy of the Soviets. The trend ended with the MiG's Flogger family and Foxbat, and Sukhoi's Flagons (with the exception of the MiG's variable-geometry wing.) Then came the fourth generation MiG-29 and Su-27.

During this time the state of the art for USAF/USN diverged from nose-intakes (after the F-100), with the Century Series all having intakes on the side (As did France's Mirage series. England's jets were the opposite, having side intakes from the start, until they deviated with the superb BAC Lightning! Then back to the side intakes with the MRC Tornado.) The Soviets stayed with the nose intake for tried-and-true, simplicity, and production. Then from the MiG-23/Su-15 on they accepted that the Western designs were superior and adopted them.

Hi Fred

First I'd like to state, that the passage you quoted is my personal opinion and not proven (but I know approx. how socialism worked and I guess I'm quite close :-) :-) )

As for nose intake or side intakes ... if you look closely the 2 engine a/c of both cold war "blocks" have nose intakes. As for earlier birds I think it is mostly a matter of trusted design. Also for me it seems easier to make a nose cone regulate the airflow, than to construct a flap system in the intakes or variable intakes. Later/newer engines were also more powerful and thus needed more air to push through the engine so a nose intake might be discarded as it no longer delivered the air drag advantage when build as large as necassary.

Another thought: advanced a/c design was and still is often a matter of propaganda(of countries or business companies) on both sides. I do not think there is an easy comparison between eastern and western airframes. It too often depends on governmental requirements we do not know. 2 Examples:

1. remember the He 177 is considered a failure often? I just recently taked to a former Bordmechaniker (~on board mechanic) who worked with Heinkel at Warnemünde. He flew with the prototypes and he said the beast flew like a charme until a certain person wanted it to be a dive bomber...

2. MiG-25: it is often said (in western literature) that it was developed to counter the B-70 Valkyrie ... maybe to justify the huge amount of work and money that went into that project OTOH eastern sources say it was developed to counter the U-2 and other "recannaissance" aircraft that could not be reached by the other fighters of that time

Whats true? We'll never know it is just a matter of perspective.

Again just my 2 euro ct.

cheers

Steffen

I know this is off topic, but if you didnt know, you can actually fly these jets for about $3,000. There is a company that offers flight tours to Moscow. I was going to do it, but work wont let me go They put you up in a hotel for 3 days, give you a flight training class, a complete physical, they even cover your meals. Youre not allowed to fly alone of course, they do send you up with a pilot, but once your up, he will let you fly the plane. There are a variety of differant jets you can fly also. I think someone should go on this trip, fly both planes and then report back to us what the differances were! LOL

www.flymig.com

Fred Soviet mechanical engineering and aerodynamics was the equal to west. Granted the west avionics were superior. The MiG-21 was the most aerodynamically pure interceptor of its time. The move to side intakes is probably down to two factors. One the increasing importance of radar and avionics. If you put a big radar in front of your plane there no room for a intake. Two with long intakes there is the risk of pressure loss.
To counter your F-100 example, the F-89 had side intakes, and the F-16 intake is almost a nose intake.
If aircraft are designed to have the similar speed and G capabilities, aerodynamics are going to dictate similar shapes.
Just my 2 penny worth.

David

Hallo Steffen, Hi David,
Keep sending your 2 euro ct. and pennies, and someday I'll be able to afford a clue! ;-)


Do you mean side intakes? I can only think of the following exceptions as twin-jet nose-breathers, the MiG-19 and the RAF's amazing BAC Lightning.
IIRC, the more powerful engines were more sophisticated, requiring more complex intakes. The F-104 did not have a powerful radar yet the design favored the side intakes, originally simple, but requiring a redesign to get the most from the power plant. I would guess the same for the Mirage III family and the amazing Saab Drakken. Then again, whereas the Starfighter was a clear air mass fighter like the MiG-21, the Mirage and Drakken were limited all-weather, equipped with (for the era) large radar for tossing radar homing missiles.

David:
Agreed, to an extent. Another factor against nose intakes, fuel and internal weapons. No VVS (Voenno-Vozdushnye Sily, Soviet Air Force) Frontovaya Aviatsiya (Frontal Aviation), or FA, design could match a contemporary USAF design for weapons load and range (except maybe the F-100.) Of course, this can be debated as form following function, that (considering only tactical missions) Soviet designs were short ranged for FEBA (Forward Edge of the Battle Area) support, USAF were built to fight past the FEBA for deep interdiction against the second echelon to starve the attacking frontline units.
Additionally, VVS acft were robust enough to fly off of unimproved airfields instead of the big concrete targets USAF was hobbled to. Nose intakes were less susceptible to FOD. That said, even MiG-23/-27 were able to operate from sod fields, with mud guards on their gear and screens for their side intakes.

Wow, what a treat to talk with him! Yes, I read that in a fly-off between the HE-177 and the JU-88, the -177 was faster and more maneuverable.

True to an extent. One thing I have learned is that there can be a complete disconnect between what a specification calls for, what a designer designs, what operations creates doctrine for and what commanders employ for. All four will have their personal concept of what the history of an airframe is. Case in point, USAF did not want F-16. Col. John Boyd and the "Fighter Mafia" wanted it to be a pure clear air mass air-superiority fighter. That is what it was bought for, but it was immediately employed for air-to-mud. I recall in 1983 being told by a visiting Viper pilot that the bomb racks then in use on F-16 were limited to about 375 Kts!
Ultimately, there is usually a 'birth certificate' for a project specifying what it was conceived for. As missions changed to reflect The Threat, so could the specs for the continuing design.

F-16 was designed to be simple. While capable of Mach 2, the simple intake is not optimized for this. IIRC, that is true of F-18, which though full of thrust and aerodynamically capable, is limited to M 1.8. Also, the ducting of the F-16 intake allows more fuselage capacity for avionics.

Totally agree with you my man. But i think the MIG-29 has a bigger resemblance to the F-15. And if we look at it from the aerodynamic point of view, then most high performance fighters are gorgeous in their appearance and very similar in external features.

Fred

My views on nose intakes versus side intakes come from discussions with my father, who is a trained aerodynamicist. Both the MiG-21 and F-104 intakes use shock cones to control the air flow. You could say that F-104 has the same intake as MiG-21, just that its split in half and mounted on the fuselage sides. The same is true for the Mirage family.

Using your argument that side intakes are better than nose intake, then the F-100 was a real step backward. As the F-80, F-89, XF-90, F-94, F3D, F4D and the F9F family all had side intakes

David

A bit off topic (sorta) about the F-16 intake.

One of the early conceptual designs had the intake moved forward and under the smaller, straight radome (pre-APG-66) and looked very similar to the A-7. And rather ugly.

As stated before the F-16 was meant to be inexpensive. It is one of the few modern, mach capable, fighters WITHOUT a variable inlet. No moving parts inside or outside the intake. No need for bulky hydraulics and mechanisms. Extra cost savings. The shape of the fuselage forward of the intake causes the airflow to be controlled in such a manner that it won't cause a 'flame out' or starve the engine for air.

Very belatedly Hi David,

I asked my friend who teaches aeronautical engineering at a service school about these matters. He deluged me in more technical aspects than I could digest. In short, for subsonic, a nose / simple intake is optimum. When you get into supersonic, the shockwave from a nose intake can increase drag beyond optimum. That is why, aside from freeing up the fuselage for weapons, fuel and avionics, we moved to side mounted intakes. They, more so than nose types, can be set for optimizing the shockwave. Moreover, side intakes can be further designed for superior air ingestion for sub-, trans-, and supersonic speeds. Regardless, a jet propulsion system is more than just the intake.

That is a very simple explanation. A fairly easy to follow explanation is available to those interested here: Jet Engines