STEALTH 103 | The important bits that nobody explains 

Few days ago Greg's aeroplanes and automobiles was referring you as a great source for difficult issues not easily found in Internet. Keep with excellent work. Grazie tanta.

Forget that 7%. 93% of us like it. That opening is one of the things that hooked me.

A really superb video. Probably one of a kind on the internet. I like the animations as well. A minor correction: the canopy coating is ITO (Indium-Tin Oxide), rather than gold. Although a very thin layer of gold could be used, ITO is preferable for a number of reasons. There's other aspects to this issue (related to both RCS reduction and 'other' issues) which go off publicly available info pretty quickly. A couple minor omissions that might be worth discussing: The aft turbine of a jet engine is also an RCS issue related to rear-aspect stealth. The air flow diverter common to most conventional intakes is another area of concern (though you've mentioned that in other videos). And the unavoidable geometry involved is having mobile control surfaces as well. I know you brought up tighter fittings between gaps before, but things like horizontal stabilizers have some rather unfortunate characteristics. In particular the need for an all moving panel to have a flat surface to move against is "unhelpful" when you consider that these flat areas are perpendicular to the horizontal stabilizer, so they're flat-vertical. And a little known detail is how a circular reflective surface (like a bearing ring) which is hidden only by a largely radar translucent material, can be a very serious issue. As for the geometry of a compressor affecting stealth, it's pretty difficult to curtail that aspect with compressor geometry, since the blades rotate through 360 degrees, and their AoA is variable if the engine is to have any sort of decent performance. Plus they are going to be pretty straight (no matter what) in order to survive the centripetal force involved. So compressor geometry is not a "high priority" aspect of the RCS mitigation, and doesn't "significantly" affect engine geometry in ways which would compromise efficiency, power, etc. There's a lot of opportunity to mitigate the radio frequency emissions while inside the intake channel. Use of highly 'radar-translucent' materials to guide the air, while more reflective surfaces are shaped instead to trap RF waves within the engine area, are pretty effective. Basically 2 overlapping geometries, one an open pathway to air, the other an open ended Faraday "chinese finger trap" to RF waves. It's much more about how RF signals get to and from the engine, than about the engine geometry itself. Actually, the old cone-style intakes have fairly favorable RCS characteristics, though it's better to more freely allow RF into the RF trap. Considering how multiple bounces off of a radar reflective surface do tend to disperse and ablate RF "to an extent", I wouldn't underestimate the raw value of blocking compressor blades from direct view. Or perhaps put another way, yes, it's not JUST about blocking the compressor from view, but you can't even get to the point where you're discussing the mitigation of wave-guide behavior until after you've blocked the compressor from direct view. Using plasma as an on/off RAM material is interesting, but it effectively blinds PESA mode if you're actively using plasma in a radome. That said, AESA/PESA array shapes are rather unhelpful to stealth, particularly at mm wavelengths, which ricochet around the tines of an array like a pinball machine. Also, the usefulness of RAM with a radome/radar is pretty limited, if you want the radar to work. So it's kind of a stealth engineering topic unto itself. There is probably a sound argument for a stealth aircraft which lacks an AESA array (the F-117 for example, simply skipped this engineering issue entirely). A fairly short video suggestion (if you're looking for ideas): "LIDAR & Stealth" (I always watch the whole thing with your channel. I skip ahead with a few youtubers who take 5-10 minutes to get to the point, but yours are not problematic at all. It's possible that some people are simply too used to other channels which waste a really large amount of time, which kinda trains viewers to be very quick to skip ahead.)

One really doesn't find such insights anywhere else on YT. Another great video!

I long suspected that the various air forces and manufacturers had no interest in making really good explanations of stealth available to the public, verging on deliberate lies- and they might have good reason but I can't get into that. Your videos are a delight to people who want to understand these matters!

I love your 'side conversations' with your 'AI Enhanced' Roomba. I am an Electrical/Electronic Engineer whose first job was working on F-4B/C/D/E for McDonnell Aircraft back in 1965-1968. You cover advanced aerospace Mechanical/Electronic topics better than any other RU-vid creator. Keep up the good work.

If nobody explains these why did I talk about them in my class the other week? 😋 Love your content, beats reading some textbooks before teaching a topic. The good case for inlet changes is the B-1. Was also an issue for the X-32.

Hey millennium! I really like the format of your videos and you always explain them so clearly. Is there any chance you could talk about flying wing drones like X-47B, X-45C, Dassault neuron, S-70 okhotnik and the techniques they use to reduce their radar cross section? This would be an very interesting topic

Found this channel only recently, but I’ve been binging all of these videos. Keep up the great content! :)

Canopy in F35 is mounted backwards because B (VTOL) version has fan behind the cockpit so they had to install hinge in front

JF-17 is the 7th generation stealth technology. It is the master of disguise because it shows itself as a large passenger jet on enemy radar.😉🤪

This is so good. More equations/ worked examples would be awesome! May be how frequency switching/ jamming works next?

Funny how some ppl argue that the su 57 isn't stealth when in reality, it is featured along with the F-22 and 35 in these videos.

Love this series!!

2:29 OTIS again asserting his dominance in the relationship. 😂😂 Yet another informative video on the topic of intake RCS reduction. It's definitely more complicated than what virtually all defense news sites make them out to be.

I've only just begun to watch this channel and I must shout out the praise for you videos that may be the most professional and balanced that I have seen! Your humour, (including the robot) are just perfect and provide enough comic relief to help me swallow the advanced technical explanations easier. I especially love your music and how it is not so loud or over used, as often is the case. Your teaching ability is great; I can understand difficult topics because you provide the right amount of relevant context and comparisons, etc. Keep up the great work!!

I really appreciate your channel, you deserve far more subs

Firstly: I have rarely seen better, technically well-founded presentations than yours. I salute you. I am a researcher specializing in history seen from a social scientific pov, combined with cultural and cross-cultural psychology. Your presentations provide a competent view on the current world of air power, and I would LOVE to co-op with you in the field of strategic analysis. Secondly: My name is Hans Dorsch. Although there is a certain German touch to it, I am from Denmark with a Swedish-Finnish heritage. You?

I like the editing much better in these videos than the old ones.

The attention to detail is what makes this channel worthwhile. Thank you for sharing.

Man. That beginning was awesome! Good video!

Very interesting, showing the limit of technology in real world. It would be nice to add subtitles btw

Support me on Subscribestar www.subscribestar.com/millenn... Support me on Patreon www.patreon.com/Millennium7

Why do you only have 33k subscribers? This is one of the best military channels on RU-vid!

Another great video. Thank you.

Very interesting stop. Never really thought about radar bouncing back out getting tanks.

I just found your channel and wish I had found it earlier. You do an amazing job with the narration.

Nice to meetyou, informative Channel u have , I'm x air force Lockheed SR71during Nam, it was a honor to work on this aircraft,still flying today, thanks for your sharing.... 12:41

Yours is an underrated channel. I appreciate your work!

I can feel my neurons waking up with your videos. Excellent work... as always. I felt improved audio. Nice!

Great video!

Great video as always! Could you do a video on angle of attack, wing loading, instantaneous turn rate and sustained turn rate and which fighters has the better or worse overall compromise between the different turn rates. And please use the Gripen as an example😉 Looking forward to whatever comes up next on your channel

Again this interesting man told me something interesting in a way that I understand and it gave me some more knowledge that I like to get. Thanks a lot! I shall appreciate a video about the antenna issue that you mentioned. An in one of the next videos about aerodynamic I shall be happy if you can explain the purpose of the very small canard fins on the Concorde and how they are working. I am still a great fan of your channel!!

That was very informative, thank you! :-)

Thank you for a massive educational effort.I learnt a lot. Thanks again.

I've seen the movie, I know everything we need to know! (great video as always!)

Great stuff!

I like the intro, keep it don't change a thing. Reminds me of Top Gear. Really enjoyed the video, love it when I learn something new.

Excellent video. Would especially like to hear more about how the radome is (presumably) optimised for outgoing waves while mitigating incoming waves.

Thanks for another informative video. I would like to ask, can't you make weapon pylons from the same materials as radome, thus transparent to radar and no corner reflections?

By the way, the opening music is necessary to establish an own personality to the channel. Makes it more unforgetful. The intro music is short and catchy. I would say there is a 92% that still hears the intro despite hearing it a thousand times. That tells a lot too. Everytime we hear the music, you are working on brand recordation and brand asociation. I would suggest to include it again. That 7% is probably impatient people that skips any part that they feel uneasy, you are risking 92% of loyalty for 7% of highly unloyal "Skippers". The music is part of this brand as the yellow pictures. I love your channel and I give these suggestions with the love and the expertice of a 9 years brand manager experience.

Thanks for the info.

this channel is fantastic, Greetings

The thumbnail game is really on top in recent videos🔥

Hello. Coatings like what was designed for the F-117 can even be used on a flat surface facing right back at the radar. The reason is because the radar energy causes an alignment of the Bohr Magnetons* in the direction of the radar energy*. When the energy gets strong enough to hit something in the aircraft it bounces back with less energy and now cannot overcome the Bohr Magnetons aligned against it. It's called " switched spins". The material has lines of forces arranged haphazardly until radar energy hits it then it lines up. That bunch of different metallic oxides you said is in the Russian aircraft might not work cumulatively like you expect. This all I have said elsewhere and is almost the maximum except the Fe50 if the F-117 is Iron Oxide Titanium Dioxide and a semi-precious gemstone. Oh and a composite below the coating helps much more than yet another substrate because of temperatures and energies needed to cause the materials to go " active". Ok thanks.

Stealth planes look so cool, the SU-57 is one of the best planes I've seen.

🇨🇵. Thx for all your videos. Very impressive, interesting, complete ...and with most issues unfund anywhere else. ... So let go and ...as system voice said " Yes lets do it sir ."

Good Stuff

Was searching for an explanation on this topic.. for a long time.... Found it here... As ofcourse information found on this channel is not easily found anywhere else....

Fascinating!

Going into the Sci-Fi area, the ADF-01 Falken solves the canopy issue by simply removing it, and adding cameras on the outside, and screens on the inside, pretty neat, but what I love the most is the COFFIN system (COnnection For Flight INterface System), it's basically the same cameras on the outside, but a VR system on your helmet, why no one thought about this yet? The XFA-27 Scarface have a different configuration, but is similar to the Falken, it has a standard canopy, but also cameras and screens on the lower side, so the pilots can see everything under them. I love sci-fi that doesn't exaggerate, and Ace Combat is one of the best sci-fi out there.

Super interesting! Would love to get some in-depth info on the radio / radar lobe emissions

introduzione abbreviata: APPROVED!

Algorithms bless this man

This was as alwayes an excellent program.

Every great man has a "Jarvis" monitoring his every word..

The non-intentionally stealthy Hawk trainer doubles its RCS when it carries its 30mm cannon pod. It also carried a radar signal enhance when used for ACM training.

Wow great channel, robot gig is good too

what a shame , you have been around for 3 years and I only discovered your channel today !

I would definitely like a more indepth video about radar reflection on SA-Radars.

Hey, just noticed some bits of news which might catch your eye Millennium 7, knowing your interests ;) There's an interesting material which was announced at North Carolina state university. (honestly the announcement itself seems very fishy to me, I would tend to think it's not really something the lab's USAF funding would like to see rushed into newspapers) And also there was a recent press release from GE on the XA100 engine (bear in mind GE's claimed margins of benefit are relative to their own YF120 engine, not the F135 engine, but still, it appears to have bettered PW's F135 engine in a number of ways) I wonder if the coating from NCU could be made to be flexible.

Hi: On minute 7:01 you mentioned that an antenna beam is closer to the reflected signal when it is illuminated from another radar, I think about the linear antenna works on a phase array antenna and i don´t see the fact you talk about, however i understand that common radars are designed to detect and not for avoid being detected, moving the tilt upward can reduce the total RCS but i am not sure how much it can be reduced. I always thought that stealth planes have a improved stealth of a usual wave length, if the radar transmit in a different frequency the stealth is no such efective.

dear sir , ihave a question for you .on the f35 why not to mount rhe rail on the tip of wing ?so you have only a rail and no pylon

More please

I'm not sure if you already did but can you please do a video comparing air defence systems around the world similar to iron dome? Thanks!

Sir i did not skip the intro sir!

When the f35 flies over our house, at very low altitude, it is remarkably quiet. I'd be interested to understand how much that is a side effect of the measures to reduce radar and thermal visibility, vs. how much that's deliberate, and how it's achieved.

Please tell more about how radar antenna reflecting waves. How about if future SAMs will have, for example 1(working at the moment) emitter and lot of receivers, located far from each other(around the target airplane)? In this case stealth shape will be not so effective, reflected radiation still reaches receiver. Also this solution have big tactical advantages.

Enjoyed it again. I have one question if I may. The Chinese J-20 has these large canards and you use to say, that canards are detrimental if you want to maintain a low radar cross section. That got me thinking. Could it be possible to disable the canards in cruise flight (so no aerodynamic function other than that of a strake or fin in this regime) and to enable it when required (when sustained maneuverablity is necessary in combat)? I got to that question looking at the Swiss Mirage IIIs, Israeli Kfirs/South Adrican Cheetahs and the Swedish Saab J(A)-37 Viggen, where the cnards seem to move either not at all or only have the aft end parts of the canard moving. I thought then: what if the PLAAF pilots have a switch that enables/disables the canards (activating a different mode in the fly by wire software?). Would it in theory be possible to have similar frontal aspect low observability if the canards do onot move as an aft placed tail plane? Or ore canards detrimental to LO regardless?

I think Otis did a great job on shaped intakes. 👍🙂

👍😊 Thank you ! P.S. Please, offer Otis one free defragmentation - he deserved it this time ..😉

He has a friend! Whats his name? And thank you for sharing you knowladge! The difference between your chanel and a good chanel is that good chanel does his research on a topic. You sir HAVE knowledge on and beyond the topic. To be be clear you better than a good channel, your unique!

@Millennium7: can you do an episode on the 1987 MBB Lampyridae German Stealth Fighter?

I need to know all of this

Could you compare how F-22 and Su-57 diferent aproach in engines in relation with stealth, please?

Could you enable automatic cc

I think that in this case, if the plane gets dirty with dust like when operating in a desert environment, this will reduce its stealth, compelling it to fly high where the air is cleaner and reducing its possible tactical usability.

What happens if you release a continuous flow of plasma over the canopy?

With regards to intakes, why are they still not placed on top of the aircraft as far back as viable to outright hide the intakes from the ground? I am aware of the downside of potentially limiting pilot visibility but with all the other tradeoffs to performance made I'm surprised this one was not taken. Planes like the YF-23 look perfect for this arrangement already having two humps on the back for the engines while the intakes still end up below the aircraft. Does this arrangement negatively effect the aircraft in other ways like at low speed causing engine stalls? If that is the case would it still not be better to have closable louvers like on the mig 29 only on the bottom instead of the top for low speed intake? arrangementisn'tadvantageous

What about the pilot's helmet. An old story I heard during the gulf war was from Oerlikon, that they were able to detect the stealthy F117 by detecting the pilot's helmet!

The 100nm layer of gold found on cockipit windows definately does not reflect radar waves. A gold (metal) plating thinner than half of the wavelenght of radiation does not reflect the radiation. Radar EM waves have several orders of magmitude longer wavelenghts than visible light. The gold layers probably just create multiple layers of matrices enbedded with radar aborbing compunds. Gold acts as a transparent glue for the aborbing material. Just speculating, of course...

Question, on propeller driven aircraft there is the constant speed variable pitch props. Why do not turbofan engines have a variable pitch fan blades?

I guess the intake blades would also cause a Doppler shift in the reflection that would be identifiable as a jet engine.

If the radome is radio transparent then what in the point of having the chine continued on it from thr fuse, wouldn't it be better if the aircraft had a conical nose(aerodynamically speaking).

I stubled across your channel by accident my gosh its beautiful but the only problem is that i have had a bit difficulty in following what you are saying

Yes I would love to see the even more detailed video on this topic. As far as I know F-35 isn't particularly stealthy in L band. Which means you can detect the plane. But with L band you won't be able to find firing solution - that is my understanding. Cheers from Poland. Stay Safe!

As I have stated before the greatest thing about this you’re station no political BS, just facts. Thank you 👍🏿

Interested.

OTIS changing someone's mind by data and reasoning is unheard of. Couldn't sleep all night! 🤪

i have a question, since stealth work more in reducing the radar effectiveness rather than pure invisibiity by the opponent, why wouldnt a country per say china build more radar and cramp them together at coastlines per say to combat such weapon system? is it a cost thing or i just lack some key knowledge thatmilitaries worldwide seems to get hence why the push for the technology?

please do a video on the ufo videos the pentagon is confirming

So, When are we going to see OTIS vs M7* , fighting it out in DCS ? ;)

Re: low observable pylons: wouldn't it be possible to create pylons that taper as they meet the wing? That should eliminate some right angles!

Would love to know ur background in this. I've enjoyed all ur content but would like to know more about u. Can u do an episode explaining why u know what u know?

This is a stupid question. Radar waves are energy can you not use this energy therefore reducing returns. Please be gentle im not rf expert

Is it me or does the camera seem a little out of focus?

Where can you buy such a smart robot cleaner?

Damn you are really good..

Hey but I thought the f 35 canopy was coated in titanium tin oxide?

I have a question for you to look into. In all the videos that I have watched that show Russian fighter pilots and have never seen them wearing G-suits like our pilots. Why is that. Thanks for your videos.