endgame
A mock up tells you very little. It is just a manifestation of lines of thought and concepts. Not necessarily of design and technology maturity.
Again to comment on our part will be immature at best, as we do not know the test conditions that they have gone through hence to acknowledge or den such platforms inevitably means that one is claiming a level of knowledge he/she does not possess, or that he/she was there when a full scale model was put through the test, after all a radars emissions and aerodynamic conditions in a actual environment are not impossible to recreate for test conditions, and this capability is available.
However consider this, when a SU-27 model was tested in the wind tunnel it was believed it could not come out of a spin.
Interview of Designer-general of the AOOT "OKB Sukhoi" Mikhail Simonov.
Question: They say that originally it was believed that the Su-27 cannot exit from a stupor.
Answer: Yes, such was the conclusion of TsAGI after wind tunnel testing of the model: the aircraft cannot exit from a stupor. Something had to be done about this. A system was developed that would not allow the plane to exceed the AOA of 24 degrees.
Not a single Su-27 model in TsAGI's wind tunnel was able to exit from the stupor. We challenged this finding by creating a 10-meter half-real-size model of our aircraft, attached it to the Tu-16 bomber and dropped it from 10,000 m. The model had an automatic guidance system that would force it into the spin and, if the model could not exit from it, a landing parachute would be deployed. We discovered that in about half of the situations the larger model would safely exit from a stupor. However, we could not tell the pilot: "Go ahead, everything is fine". And thus we had to agree with TsAGI and establish limits for the aircraft's performance. This was all very strange: we wanted to achieve high angles of attack but could not produced a plane capable of doing this.
The most interesting situation occurred during flight testing. Fighter testing is an enormous work requiring about five thousand test flight, during which the machine is tested for structural strength, its aerodynamic properties, it ability to deliver and deploy weapons and other aspects of performance. Even before the "Cobra" maneuver, Victor Pugachev was performing high AOA maneuvers. I was very worried about this because I knew about the problems experienced by the American F-16 fighter during high AOA testing, when the aircraft was able to achieve a 60-deg. angle of attack but was only able to exit from this maneuver by using a special anti-spin parachute. We chose a different approach to testing our plane, but were still very apprehensive when Pugachev entered a high AOA. However, he was able to exit from it and everything ended well.
Further testing proved that the Su-27 would not fall into a spin when performing high AOA maneuvers. The results have shown that it is possible to take the plane to high angles of attack and then return it safely to the normal mode of operation. This finding was what opened the future for supermaneuverability. But 20 years ago we could not realize this, we were conducting just the first test flights.
During one of such flight conducted by test-pilot V. Kotlov experienced a depressurization of the air pressure sensor 6, which gave him an incorrect air speed reading. The pilot tried to compensate what he though was very high speed by increasing the climb angle and finally the aircraft came to rest in a vertical position at an altitude of 8000 meters and started sliding down with its tail first. The pilot's hopes that the plane will eventually return to normal flight did not materialize, instead the aircraft seemed to be "suspended" between the sky and the ground. This was unexpected and baffling: the air speed was near zero and the altitude was 8000 meters. The pilot panicked, he switched off the afterburners and immediately engaged them again. The plane started falling on its tail and the pilot experienced weightlessness - in the future this maneuver was to be called the "Kolokol", or the "Bell". 7
question: And all of that happened in just a few seconds?
answer: About 20 seconds. In the air it seems like much longer. Once the aircraft has reached the 60-deg. AOA (and we only had the permission for 24 degrees) the aircraft fell into a spin and started spinning with its nose pointed toward the ground. The pilot then realized what has happened and reported to the ground controller: "Stupor!" Since it was believed that an Su-27 cannot exit from a stupor, the ground controller's only order for the pilot was as if struck in stone: "Eject at an altitude of no lower than 4,000 meters."
Ejecting is hardly a pilot's favorite thing to do, thus to avoid serious injuries the pilots has released the controls and started preparing for the ejection. However, at the last moment he noticed that the aircraft had exited from the spin and now beginning to exit from the dive as well. The Su-27, when left on its own, was able to return to the normal flight. After verifying that the aircraft was still controllable, Kotlov made a safe landing.
question: Perhaps this was just a coincidence?
answer: This was our conclusion at first as well: for the 1000 flights this was the only such situation. On the big count this did not matter. However, a shirt time later an even more incredible situation occurred in the Far East. An Su-27 pilot was performing an automatic intercept exercise. The plane exceeded the critical angle of attack and entered a stupor. Following the order from the ground controller the pilot ejected, after which the Su-27 exited from the spin and the autopilot resumed its course until the plane ran out of fuel. Soon after a third such incident occurred in Lipetsk8. This forced us to establish a special research plan to investigate this phenomenon. As it turned out during the course of the investigation, the Su-27 exhibited certain instability when entering the spin and exiting from it. It was established that even the most effective aerodynamic methods for exiting from a spin did not always result in the desired outcome. At the same time in a number of situations the plane would exit from a spin on its own when the position of its control surfaces was neutral. This was later explained by the peculiarities of the Su-27's air vortex aerodynamics at various angles of glide and attack.
A considerable role in our "victory" over the spin was played by the accomplished test-pilot, cosmonaut Igor Volk. He conducted a series of test flights and determined that the Su-27 can exit from all variations of a stupor.
qestion: So why did model tests resulted in an opposite conclusion?
answer: It turned out that it wasn't the aircraft's layout but the size of the model that mattered most in this situation (the Reynolds number9 in fluid dynamics connects the speed of flight, the size of the aircraft and the viscosity of air and this number is considerably greater for full-size aircraft than for their small-scale models.)
source:
http://vayu-sena.tripod.com/interview-simonov1.html
Note: this is what I mean by the aforementioned credible source of information.
Which goes to show the differences between design and actual testing, again the level of simulations has significantly increased as more processing speed and a greater understanding of the environment is at hand, leading to better engines (simulators/wind tunnels) to recreate the actual environment, however by what degree is something I am unaware of.
This is why I am not interested in the complexity of a high tech mock up.
About the effects of speed and exhaust of an aircraft, no level of IR shielding can deny you the availability of the heat generated from the exhaust and as a result of interaction with atmosphere, you can at best minimize it through the steps taken by US on its various stealth programs,
The only credible comment available online that I know of remains to be the comments of RAAF Squadron Leader Stephen Chappell, F-15 exchange pilot in the 65th Aggressor Squadron
"The [F-22] denies your ability to put a weapons system on it, even when I can see it through the canopy. It's the most frustrated I've ever been."
This in terms of IR reduction can mean this:
-They have managed to reduce the IR level below the ability of the missile seeker, as to my knowledge, the F15 carries neither an IRST nor an OLS. The missile in question is also unknown, if it is an older US missile it might lack the processing to make sense of complex situations,
As opposed to say a python-5 which
/with a more evolved IIR seeker, improvements in processing equipment, and the required preprogrammed instructions to make better sense of situations that are different-changing/
Performs better than a python-4,
if one claims that the IR dissipation is mixed with the background environment which will be the only way to truly hide it, he/she should see what the temperature conditions at a certain height are(take 30,000 feet) and compare that with what the IIR sensor will transmit to the brains of the sensor.
- He was not talking about the heat seeking missile in which case why am I typing this.
Low level supersonic cruise missiles are not stealthy. They can neutralise all radiation trying to detect them, they can shape them, make them completely out of RAM, but the ionisation trail and IR signature created from the interaction with the atmosohere is a huge give away.
Given the obvious nature of heat signature of all things flying at any decent speed weather supersonic or subsonic and both from the body and exhaust, the missile cannot be a exception to the rule, however one cannot deny/accept exactly what level of RCS reduction in what way has gone in their missiles, until their are only certain body shapes and metals able to deflect radar emissions, and one can says categorically that the missile in question clearly doesn’t posses it.
Here is the deal, when you see a missile test report or article (stating that missile traveled from A-B and hit/missed/launched the payload) you will clearly know whether the missile is accurate or not,
An example being the GSLV rocket by india for launching heavy payloads into space, that failed on national tv last year and went to the aforementioned space this year to launch the payload, one or two more successful launches will establish the reliability of the platform.
When you see a clear report/comment about the RCS of that missile on radar, you will know about the effectiveness of radar signature management.
With out them it will be anyone’s guess.
Again one of the people who might have a say in this will be Mr. Noshir Sheriarji Gowadia, he might have spoken already, although the technology might be further refined by now.
-The sepecat jaguar at a RCS of 3-4 m2(assuming) with 70 % reduction becomes 0.9 m2 – 1.2 m2, Very significant figures which imply a lot.
As for the people commenting on shielding a plane through a dense electromagnetic field (Plasma generation seems to be a side effect) I will like to see some links (for increasing my knowledge or a reference to a book, or a report on which the comment/opinion is based.
Now concerned Russian approach- mainly from article
- as I see - main point for Russian constructors was- how to achieve low RCS with hight aerodynamics parameters. So currently it was kind of compromise between total stealth doctrine (with its very bad aerodinamics) and unified jet platform with wide range of possible speed- altitue- manuverable modes. So huge effort was done in way of RAM coating. I suppose that basicaly rumors concerned "plasma stealth" based on specific way of forming such coatings - in low temperature plasma cloud.
In some sources they called "Plasma coating". But nevertheless in the article
http://vivovoco.rsl.ru/VV/JOURNAL/VRAN/03_10/STELLS.HTM which i mention in previous post there is direct reference on using plasma in particular case of radio absorption shield of radar bay of Aircraft and flight tests and high effectiveness of this device. -
Drandul (thank you for that it was very informative, can the whole thing be translated please, I am really interested.
What ever I have read online about this topic
Shielding a plane through a dense electromagnetic field (Plasma generation seems to be a side effect), as with all technology this dense electromagnetic will be seen as ECM, easily dealt with passive guided AAM, it is like the game of jamming for survival, a sophisticated missile can theoretically home on jamming as soon as it starts, the moment you switch off jamming, its resumes regular guidance, the process going on and off, like the process of switching on and off of a switch.
How will there be a generator and associated equipment on a fighter plane to get this electromagnetic field, is there any paper or presentation on generation of strong electromagnetic fields through minimal use of equipment and electricity.
If it is so then they might be using covering the randome, the compressor blades, tips, and weapon stations, with EM screening, and using ram etc for other parts.
Again things which until someone is involved in a Russian design team as scientist/engineers they can neither deny nor accept.
Hence it might be better to talk about a F-16-17-18 or a MiG 29, Su-27-30 as there are people who have worked on the project (as scientists, engineers), and with the machine (as pilots, engineers, crew) that are available for informed opinions.
If the aim is pointless arguments about things I can not gather any information about, please go ahead as I can bring nothing to the table, may be you all can.
Have you seen ultra violet lamps in night clubs ? - actually it's one of wide spectruum of different plasma condition. Even more- plasma do not need to have any radiation in IR spectrum diapason - it depends on the way - how plasma is generated and some other parameters like temperature, concentration. Particular case- Microwave discharge plasma. Second point- how to see thru it - you do not need to cover all plane - just most necessery parts of hull - like air intake system, nozzle, radar compartment, additional surface joints (flaps, aileron etc.)