How Flight Simulators Trick Your Brain

[@FlyByMax]

A couple of things that didn't make it into the video: - 0:12 the F-18 crash is documented by the US Naval Aerospace Research Laboratory, see page 10-7: apps.dtic.mil/sti/tr/pdf/ADP013854.pdf - 6:57 notice how when the roll gets washed out back to neutral, it returns slower than the initial excitement. This makes sure that the pilots feel the initial roll (rate), but won't sense the platform going back to zero roll. - 13:04 the reason it's easier to compute aerodynamic and thrust forces is because these need to be calculated anyways to simulate and model the aircraft. For example, X-Plane has an option for directly outputting the aerodynamic/thrust forces along the aircraft's axes, which I could use as inputs for the animations. Computing gravity and acceleration would require determining angles and geometry, which makes the whole thing more convoluted. - 14:16 since we now have a solution for specific force in both directions (forward and side-ways), this means we can replicate specific force in the entire horizontal plane through a linear combination of both directions. However, in the vertical direction, it's only possible to replicate short, high-frequency movements, since the simulator can't be tilted to sustain long-term forces in the vertical direction (which is in-line with gravity). For sustained vertical g-force, some sort of centrifuge would be required, like in this simulator: desdemona.eu

[@Cyberdactyl]

AND, the sim can NEVER exhibit or simulate anything above 1 gee.

[@leogoe]

@@Cyberdactyl It can actually do that short-term through quick translational movement

[@Cyberdactyl]

@@leogoe Well . . .sure. . . for like about a quarter second or for vibration effects but no +1 gee maneuvers.

[@douginorlando6260]

High G training would be good. Besides learning grunt breathing, turning your head under high G is a challenge. Familiarization with sudden G forces during carrier takeoffs and landings. Two simulator approaches besides centrifuge are 1… perhaps a motion platform that can pitch up or down through a full 360 degrees, but not roll or yaw 2… a pilot suit with 50 tension cables attached to pull on body parts (head forward, back, down, up, left right, chest forward down back, legs, arms)

[@FlyByMax]

Very good point :)

[@martin.argerami]

It astonishes me that a pilot would take off at night, over the ocean, with everything pitch black, and not be fixated on the attitude indicator.

[@Medieval_Productions]

Yeah wtf was dude looking at if NOT that?

[@blaster-zy7xx]

We scan the primary flight instruments with the attitude indicator as the “home” gauge. Then airspeed, heading, and/or GPS , assuming we are still hand flying the aircraft.

[@Stoney3K]

@@Medieval_Productions Especially given the fact that it's right in front of his face in the HUD.

[@MichaelBarry-gz9xl]

My thoughts exactly, you don't get to fly from carriers without being highly experienced, he should have been fixated on his instruments and ignored his sensations.

[@bombcat5517]

i like how this entire reply section is full of people who haven't even stepped into a cockpit before saying "he should've just not crashed like its that easy guys"

[@MarcSacksZA]

"yumans" "hyumans" "newmans" what a journey

[@YippeePlopFork]

Forgive him: he’s northern and he knows not what he doo 😁

[@33lost]

It's so funny

[@LeftInStone]

Fun fact: humans are actually called hyuman in a certain anime

[@NOTMEVR]

Mewings

[@GardenData61371]

Hoomans

[@privatepilot4064]

I had worked for a simulation manufacturer in the late 80s and early 90s in Tampa Florida and we had some pretty cutting edge technology back then. This is next generation stuff here. Exceptional video.

[@lithium25693]

did you work for cae

[@cecielhelder5923]

I’ve got a 6dof platform at home. Not as fancy as the one in Delft, of course. Maximum load capacity is 150kg. Enough for a seat, three monitors and flight gear. With VR gear the motion cues are very effective. If I use the monitors the rest of the room needs to be dark or my peripheral vision picks up the room. Works great with both X-Plane and MSFS2020.

[@serge933]

I am a sim tech at United and you would love to know we still have a 767 full flight simulator in service from CAE that was built in 1982. My favourite out of all the machines we have.

[@NickyHonings]

I've done my training on the new CAE Airbus A220 (Bombardier CS300/100) sim. Before that I did training on the Jetstream 32 sim from the 70s that needed a whole room just for the PC. but the Sims now are so realistic it's incredible

[@privatepilot4064]

@@lithium25693 Contraves, CAE was our competitor. Many of our people were from CAE.

[@fanBladeOne]

And here I was thinking this was going to be a clickbait video. Now I don't even trust gravity anymore. Thanks for that.

[@MrTommispilot]

You are not the brightest candle.

[@fanBladeOne]

@@MrTommispilot BSc Aviation Engineering, PPL(A). Thank you very much.

[@sciencecompliance235]

@@MrTommispilot Jeez dude, get your sarcasm detector calibrated.

[@jimsteinway695]

@@fanBladeOneI enjoyed your sarcasm and humor . I’m an engineer too, apparently MrTommispilot is a bus driver in the sky. BSEE worked in Naval Aviation for 25 years

[@stevenlarson3316]

And then you listen to a physicist, who says gravity isn't real, you're accelerating up at 9.8 meters a second squared due to the curvature of spacetime caused by the Earth's mass.

[@toxdaz]

*watches video on airplanes* "In 2001" "ah shit, here we go again"

[@AntonDVasiliev-ss1ie]

💀💀💀

[@Crazy-fs2kx]

💀

[@jwizardc]

This is the best piece I have ever seen on flight simulation. I have written software for flight simulators for 30+ years; both games and actual full flight simulators. Thank you for making a video that I can use to explain the rather obscure and mysterious magic behind pilot training.

[@FlyByMax]

Thank you!

[@68at97]

do you know why the actual visual quality is so bad in FFS? Ive always wondered as I feel like that would be somewhat important especially for immersion

[@themalhotras1597]

@@68at97im a bit late but i think it’s bc of the projectors

[@MeppyMan]

I’m an ex pilot (H) and used to skate vert half pipes. Love how you made that connection and it made me realise something I’d never thought about as an adult. Cheers.

[@FlyByMax]

Thanks, really glad you enjoyed!

[@MrTommispilot]

Einstein already said that you cannot distinguish between gravity and acceleration without a reference. Very well done!

[@Systox25]

Because gravity is acceleration

[@krumuvecis]

@@Systox25 No, it is force. It becomes acceleration when divided by mass.

[@Systox25]

@@krumuvecis true

[@freshrockpapa-e7799]

@@krumuvecis actually it's the curvature of space-time.

[@Jojo-210]

@@krumuvecisGravity is not a force. Gravity is the curvature of spacetime. The resistance to gravity (for example by standing on the earth) is a force. So standing on the earth under the influence of gravity is equivalent to an earth accelerating upwards with the 9.806…m/s^2

[@mitchellh5869]

As someone who trains in sims regularly as a professional pilot, my experience is thus: usually the first time back in a sim after it's been awhile my brain knows "something" is wrong, and I tend to just be a little disoriented and maybe a bit queasy for the first 30 minutes. However, after a while my brain recalibrates and adapts to the sim and it becomes really cool how well it just "accepts" it. The motion is pretty well matched with the inputs and visuals. Especially that surge axis is perfect for quick jolts like turbulence or landings. Not for nothing too, having a perfectly replicated cockpit inside helps a lot, because you're leaning/reaching/turning your head in exactly the same way you would in the real airplane, and all of this motion is completely independent of the orientation of your body, so the illusion remains even when you're not sitting perfectly in the chair looking straight ahead.

[@severoon]

I wonder if the reason your brain recognizes a difference is because there are fundamental limitations on what a sim can do, or if the sim just isn't quite accounting for everything due to cost or other non-fundamental limitations.

[@daysofend]

How does it handle a stall and altitude loss? Tipping forward? I assume it's almost impossible to replicate the freefall in the sim.

[@FatTracksMusic]

​@@daysofend33 y

[@Hamachingo]

@@severoon Meta has done studies with VR goggles. The one that really surprised them was how much dynamic range makes a difference. When you look at the sky and it's actually bright and your pupils contract, it's a massive boost to immersion. I'm willing to bet that visual and auditory clues play a huge part. I once was in a static A320 sim so no hydraulics and I could swear the thing was moving when using the ailerons.

[@Hamachingo]

@@daysofend I don't thing maintaining a stall is meaningful training, would be like a car simulator replicating crashing into a tree accurately so you can practice that. I guess the cabin slowly moves up right as you're about to stall and then moves down at the beginning of the stall to get you used to that sensation of going weightless and hanging in the seatbelts. The transition is the important part, a pilot should be able to recover at the beginning of the stall. A commercial airliner is fairly hard to stall but once it does it's more or less doomed anyway.

[@fridaycaliforniaa236]

When I was a miltary pilot, we had two sims : one like this one, the other was a simple set just put on the ground. No moving parts, just a fake cockpit and some 3D rendering on a 180° screen. You know what, just watching the scenery move while you are simulating the flight gives your brain the sensation that the whole thing is moving. While we were tied to the ground, there was no hydraulic systems, no moving parts or whatever. Visual senses are really powerful to trick you in believing your're moving while you're not ^^

[@Xg4531YT]

For me when you dont click read more it says cock and not cockpit 😭😭😭

[@dn1z336]

As someone who flew cessna 172 in real life. when i fly in vr it even tricks my brain into feeling the feelings i used to feel in real cessna 172

[@bumpedhishead636]

Motion base simulators are great for lower dynamic aircraft like passenger/cargo jets & bombers, but not great for high dynamic aircraft like fighters. Pilots can be taught that if they pull hard G's long enough, the G-force will eventually reduce - which is NOT correct. Back in the 1980s, we used an air-driven G-seat & G-suit in the simulator that would give the correct cues for a fighter pilot. We also used the visual system to give tunnel vision at very high Gs.

[@kinfongyeung5400]

i was wondering how G-force can be reproduced in the simulator since the setup appears to only have ~1g to work with

[@sciencecompliance235]

How do you sustain accelerations higher than 1g? Any system I can think of would saturate pretty quickly and take an insane amount of space.

[@bumpedhishead636]

@@sciencecompliance235 It is not about generating the actual G-force. It is about providing the cues of high-G, namely that at high G's, your G-suit squeezes you, and the higher the G, the harder the squeeze.

[@CaptainBlackadder75]

It would be elaborate, large, and very very expensive, but I wonder if you could combine a multi-axis pod with a centrifuge. That could theoretically give you all the g you could ever need.

[@kinfongyeung5400]

@@CaptainBlackadder75 the problem I see, although I know little about centrifuges, is that say you went from straight and level flight to a 90deg banking turn, the g loading would went from 1ish to say like 6 almost instantaneously. And the moment you leave the turn, the g loading need to go back to 1 very quickly. I’m not sure if centrifuge is capable of this. The second problem I see is that even if the first problem is addressed, the constant acceleration and deceleration it has to handle per flight would be so immense that I’m not sure if the engineering complexity is justified. I guess at the end of the day, the best way to learn fly a jet is to just fly in a jet.

[@DasIllu]

So when i'm in bed, i am actually accelerating forward with 1g. I'll keep that in mind next time someone calls me lazy ;-)

[@hoaxial2090]

You’re always in +1g when you’re not moving. Unless you jump or get into a machine or device that alters it. You’re just chilling in +1g 😎

[@krumuvecis]

You're only accelerating, if your velocity changes. If not, then acceleration is 0 and your motion is uniform.

[@MichaelBarry-gz9xl]

Not only that, but you're bed is also travelling at almost 671 million mph

[@cataclystp]

​@@MichaelBarry-gz9xlwhat are you talking about? earth isn't moving at the speed of light?

[@MichaelBarry-gz9xl]

@cataclystp Everything is always moving at precisely the speed of light. It is the only speed things can move, but it's the speed through space AND time, so if you move at 1% speed of light through space you must move at 99% speed of light through time 🤯

[@adamalsharif8597]

0:28 gotta get this for DCS

[@mikemcculley]

FlyByMax: “If gravity and acceleration are in some sense the same…” Einstein: “Excuse me? In some sense?”

[@alanward9521]

Wow, that was truly amazing. Having just recently flown in an A320 commercial sim, seeing this on my feed was perfect timing. I never really felt much motion as I flew the sim in a very realistic manner, but if I go again, I'll have them ramp up the turbulents or crosswind so I can feel more.. Thank you so much for making this clip and how great your narration and presentation is. Top class.

[@FlyByMax]

Very kind, thank you so much for your comment :)

[@THR2024]

10:09 is no on gonna talk about how sick that transition was?

[@felix_jc]

What an amazing comeback !!!!

[@FlyByMax]

Thank you!!

[@CapitaineNautilus]

That's how I envisioned motion systems worked, but you explained it very well and in details. I learned a lot. Thanks!

[@donepearce]

The one part you missed was braking on the runway, why presumably needs the simulator to tip downwards with a very brief upward movement of the scenery to simulate the nose dip when brakes are applied. Otherwise I'm very happy to say that all this works in exactly the way I was expecting it to. I'm an electronics engineer so instead of washout filters, I would simply say AC coupling so the steady state does not make it through the system. The turnover frequency of the coupling gives the time needed for the system to return to centre after the load is applied.

[@ocks_dev_vlogs]

One thing to note about mimicking linear acceleration with tilting the seat in the simulator, it would actually be somewhat noticeable because while the horizontal component of gravity would match the acceleration, the vertical component would be reduced making the seat feel like it is pushing you up less. This method of miming the acceleration could also only simulate up to 1 g of force by only rotating and would feel less and less like what it is mimicking as it approaches that max force.

[@FlyByMax]

That's a fair point, although I think the visual part of the illusion would far outweigh this effect. Thanks!

[@FlyNAA]

This is true, but just not significant. The losses and gains don't add up to a constant. If you tilt back 10 degrees, you've gained 0.17 G longitudinally (sin 10), but still have 0.985 G vertically (cos 10). No one can feel that loss. Much more significant, is the complete lack of sustained G in turns. Should be doing 1.15 G in a 30 degree bank, and only feeling 1.00 is definitely annoying, if not outright distracting sometimes.

[@DreamOfFlying]

@@FlyNAAexactly my thought. This tech would be useless for fighter pilots. Still very cool for airliners though!

[@Isegawa2001]

​@@DreamOfFlyingAFAIK Fighter sims use centrfigues.

[@Stiiin]

10:35 Gravity and acceleration are indistinguishable because they're basically the same thing. That's Einstein's equivalence principle

[@benbookworm]

I took a free online intro aeronautics course from TU Delft some years back, and it was incredibly fascinating. It did require a fair amount of math.

[@GordonWrigley]

I love the detailed explanation. Too many channels give the basic idea and leave out the detail.

[@FlyByMax]

Glad you enjoyed!

[@hexago-motion1454]

Well explained!!! Without cutting any corners. I tip my hat off to that.

[@FlyByMax]

Thanks!

[@gomini3707]

Your videos are also exceptional Hexago ! Hope you will keep them coming too.

[@tgsredfield]

So glad to see one of the best aviation channels I've ever seen back. Excellent video!

[@markplain2555]

I had the opportunity to 'play' in a jet fighter simulator that can flip upside down. I was VERY impressed by the sensations. I have always wondered about how a simulator can fool you into thinking you are climbing. This video was great - thanks. . . . As a side note - I am a glider pilot - I once climbed into a cloud with an instructor (and only VFR instruments). We wanted to test my ability to sense the g-forces when visual cues are removed. I thought we were flying straight and level, but when we popped out the side of the cloud we were actually in a relatively steep descent with one wing down. Wow what a sensation; the power and importance of the visual horizon. . Last year I flew in France. We took off in a valley and I suddenly found myself desperately looking around between the mountains to get a glimpse of the horizon just to orientate myself.

[@FlyByMax]

Thanks! Great to hear your experiences.

[@michaelhoffmann2891]

For non pilots, just a minor addition on how strong and fatal this disorientation can be when you lack visual cues and only rely on your "lying inner ear": As per FAA and NTSB studies from years ago, pilots who do not have an instrument rating, but end up flying into clouds, have a life expectancy of about 97 seconds. One and a half minutes, before your disorientation takes you into a so-called graveyard spiral and you crash. It's that bad! Which is why instrument training drills trusting your instruments and ignore all other cues. It would be interesting to find out why this Navy pilot didn't do that. EDIT: reading the linked Navy report now and see that it makes reference to that.

[@FlyByMax]

Good comment!

[@shuminyao9750]

The simulator is much more complex than I initially thought. Great video showing the engineering difficulty.

[@alexandleighdefazio7221]

Best explanation I’ve seen in my 28 year flying career. Well done!

[@FlyByMax]

Thank you!

[@tangocharlie9291]

As a pilot, I’m aware of Spatial Disorientation and that it is generally caused by the inner ear and visual cues (or lack thereof) but wasn’t aware of exactly *what* senses get mixed up. 11:38 explained it perfectly. Thank you!

[@anonda737]

This is incredibly thorough. The explanations are easily understandable. Appreciate the great work.

[@Ahsan_Fazal]

I didn’t even know we had this simulator… And I’m a student at the faculty of aerospace engineering of the TU Delft haha 😅

[@kre4ture218]

I‘ve been in a simulator like this, for the P3 sub hunter. It‘s absolutely amazing how well it translates the movements into forces you feel. Although after some time I got a bit queasy so I left the sim and watched from the outside, seeing how it works. It‘s just incredible, to watch these arms tilt around a mass of several tons seemingly without effort.

[@Jvcaetanoo]

Superb Max! Having worked there, it means even a whole lot more!

[@FlyByMax]

Thank you so much!

[@sumpurnashrestha]

I've wondered about the physics behind the simulators but didn't know a whole lot about it. Nice to see an in-depth video about it!

[@ROLZILLA]

Why does this vid only have 2k views, this needs at least 50k! Great work man

[@FlyByMax]

Thanks!

[@Spaceman0025]

6k 🎉

[@blaster-zy7xx]

Half a million views now!

[@henrivanbemmel]

Yes, there are two independant factors here, what jacks do and what the display does. This example integrates it. Amazing.

[@pinethegangsta]

Awesome video once again! Great to see you back.

[@FlyByMax]

Great to see you again! I remember you from my very first video, thanks for all the years of support!

[@cocolasticot9027]

I was able to guess every trick while watching, but it's so pleasant to see such amazing content. Kudos for the clarity of your explanations and the impeccable visuals, this is high quality educational material ❤

[@pulidoggy]

Same for me, with the pleasant anticipation feeling of having every intuition confirmed as they "popped up" (like the need for washout filters and surge axis) as if someone was reading your thoughts 😀

[@r0cketplumber]

I got to fly a B1-B simulator at Dyess AFB about 20 years ago, and when the sim operator relented and turned on the motion base, it got WORLDS easier to control, it just felt right. In the sim we dropped a massive boom on Abilene and then cruised 50 miles north to see the location of the sim op's fishing shack on Lake Stamford. Flying supersonic at 300 feet even if only in a sim is AWESOME.

[@SgfGustafsson]

In my experience the most realistic part of the sim is straight and level flight through turbulence, or the feel of turbulence with spoilers deployed and the vibrations from hitting stuff with the nose wheel. The biggest inaccuracy is due to the sim’s inability to simulate g forces accurately in the vertical plane.

[@DreamOfFlying]

Exactly what I thought. It can’t do anything above 1G

[@thinknirmal]

Videos like this make me appreciate KZbin even more. Great work!

[@FlyByMax]

Thank you!

[@greyflow]

Really interesting and surprisingly intuitive. I tend to get slightly nauseous on planes and one thing I do to try and make it better is I focus on my sense of balance and try to visualize the orientation of the plane based on my senses. I noticed a feeling of rotation at the beginning and the end of when the plane rotates, and that's perfectly simulated here with those washout filters!

[@olavrask9729]

Excellent video :) If i understand it right in summary its all about the force experienced by the pilot. In a real aircraft the force vector will shift with acceleration (either in translation or orientation). However in the simulator the force vector is static (gravity), so instead the orientation of the horizontal plane is manipulated. Simplified what the simulator does is it matches the angle between the force vector and horizontal plane experienced in the real aircraft by offsetting the perceived horizontal plane in relation to it's static force vector. As the aircraft accelerates the force vector is shifted backwards at an angle and so the simulator pitches up to match the angle of the "horizontal" plane to the static force vector. As the plane stops accelerating the force vector is again straight down so the simulator pitches back down to level.

[@FlyByMax]

Yes! Exactly right :)

[@aahhhhhhhhhh]

this makes me think of those carnival rides that just spin fast as you lay nearly vertical. the way it tricks your brain into thinking that you are laying down is still one of the craziest experiences I have felt, even though it was just a small carnival ride. you can feel the spinning too, so it feels like you're going to spin upside-down and fall but you never do. if you haven't gone on one of those rides, I recommend it.

[@alan133]

I played VTOL VR and the visual cues alone can trick you into feeling you are actually flying. Can't imagine how coupling that with an actual simulator that throws your body around.

[@dannileigh6426]

I find the somatographic effect so interesting, and the better understanding of it and how it is applied to both sim flight training and the human factors of a number of aircraft crashes (like the F/A-18 catapult crash mentioned in the beginning).

[@jonathanparle8429]

Very interesting. I have to admit I had not thought about this concept very deeply but it all makes good sense. I wonder though in a roll for example, in order to zero the force out the simulator needs to return from the roll position to level, but what prevents that roll back to level applying an unrealistic force to the pilot? In the real world when entering a roll, the forces are the initial roll force in that direction then neutral assuming a properly coordinated turn. But the simulator has no alternative but to apply roll in that direction, then roll in the opposite direction then neutral. I assume it must do it in such a subtle way that the unwanted effect is minimal.

[@FlyByMax]

This is an AMAZING question!! You’re absolutely right, when the simulator ‘washes out’ the roll back to neutral, it does this far slower than the initial excitement. That way your vestibular system only senses the initial impulse, not the returning to neutral. You can see this very clearly at 6:40 on the right in the shape of the curve (very steep at first, then smooths out). Great comment.

[@aaronmurphy7772]

Really great presentation! Aircraft maneuvering is generally described with the following terms: Aircraft Movements are dynamic and are Pitch (Elevator), Roll (Aileron) and Yaw (Rudder). Aircraft Attitudes are static and are Banked, Climb, Descent, Cruise and Slip/Skid. Aircraft Movements are in relation to the aircraft axes. Aircraft Attitudes are in relation to the Horizon. The Pilot Pitches the nose up to Climb, down to Descend, level to Cruise. The Pilot Rolls the aircraft into a Banked Attitude to turn. The Pilot uses Rudder and opposite Aileron inputs to Yaw and Roll the aircraft into a Slip Attitude or too much rudder for the amount of aileron to put the aircraft in a Skid Attitude. Slip and Skid are indicated on the Aircraft Turn Coordinator. Attitudes are displayed on the Attitude Indicator (aka Artificial Horizon) and also by looking out the front window at the natural horizon in VFR weather.

[@LM-47]

I’ll never forget being on break at flight school, I asked one of the other pairs of students if their instructor let them go in motion. They answered with an affirmative ‘yes’. I was surprised, mine didn’t. Their instructor poked his head out of his office and said ‘no we weren’t’. The visuals tricked their bodies into thinking their simulators were on motion!

[@EmberLorewin]

😮 This is one of the coolest things I've ever seen. I wonder how it would have felt to be one of the first people to design and program these things.

[@sundar999]

This was really interesting! I think that if you are building or buying an airliner home cockpit you really don't need motion. When flying an airliner you are supposed to do it very gently to not upset the passengers. The only sensations they'll feel is acceleration before take off, turbulence in the air if any, and deceleration when braking after landing. In a turn you fly coordinated at max 30 degrees so you won't notice except when looking out the window. You will notice the plane pitching down a little after starting to descend, but I don't consider any of the sensations mentioned important enough to buy expensive stuff to mimick. On the other hand if the simulator was for a fighter aircraft it would be much more important with a motion platform.

[@daanbondt3167]

I feel like I've reached a new level of nerd, all these science videos with 'it's not what you think' are exactly like I thought they were gonna be

[@phillyphakename1255]

I have the same brain as the engineers who built it. I understand black box algorithms, I understand the inputs and outputs of the vestibular system. I understand the math of inpulses and dampening filters. I can figure it out by looking at the obect, examining its inputs and outputs, and making a good guess about it. That comes from putting in the time to learn and think about it, not intelligence, Ive been doing this for a decade, the same 10,000 that Malcolm Gladwell says it takes to become an expert. If you are genuine in your question, I would say that its important to recognize the process which leads you to "its intuitive". Acknowledge that we all learn about forces and accellerations and dampening differential equations in college. We all deconstruct the things around us to figure out how they work, we all have curated a brain that excells at considering the factors involved in a problem and solving them. Thats engineering, and I studied it in college, and have been doing it for half a decade professionally and the same as a hobby/fascination. Its not bragging to have your work be somewhat intuitive.

[@robertbriscoe-mf2tx]

The fidelity of Level D simulators is so good that in the US, pilots can receive a type rating without actually flying the aircraft. For many airline pilots, the first time they ever fly the actual airplane with passengers aboard may be the first time they have ever actually flown the aircraft. They will have a check airman with them, but its still pretty amazing to think they have never actually flown the aircraft before.

[@AlvaroALorite]

One apparent limitation with the simulator, in the configuration you showed, is that it cannot simulate constant acceleration over 1g

[@DreamOfFlying]

Nor can you do turns higher then 1g

[@JonnyMack33]

I was blown away as a kid when I felt the acceleration in a simulator..I asked my dad how it worked and he said they blow air in your face while tipping you back, but you're still "looking forward" ... genuis

[@rafaelbudeu867]

Amazing video as always!!!

[@AutoFirePad]

Thanks for the video! Interesting how those mistakes happen even with HUD information.

[@fredrikrhenman3056]

Amazing Video, animations look super cool!!!

[@FlyByMax]

Thanks Fredrik!

[@u12bdragon]

15:40 pilot bro apparently has the memory of a goldfish, not remembering that he was launched pretty much completely level off of an aircraft carrier less than 5 seconds prior, and that there's no way he could be rotated at such a drastic angle. Also I feel like even if you were completely blind, as long as you knew you were in a high-speed aircraft and had just taken off, it would be very hard to mistake the forces you're feeling for gravity. I feel like in most scenarios your eyes do play a role in determining if the specific force is gravity or acceleration, but I feel like in this scenario you have enough context that I think the human brain would not make that mistake, even on instinct, as in you would know it was acceleration and wouldn't have to think twice about it. But here we are so I guess I'm wrong.

[@meekomeekz]

Sounds like you've never been in an airplane bruh...

[@saulgaming954]

Here i am thinking this will be a video about the inside of the sim but now I'm here with a whole ass lecture and confused how i got my self into this

[@pholdstock]

Excellent video. I have a couple of scenarios which I think may be related to this that I’ve never understood. Worth knowing that I am actually completely blind. 1. When on a train, I can not always tell if we are going forward our backwards. I assume this is due to me not being able to look out of the window and the force of the seat would either be very low when the train first sets off in a forward motion or non-existent if the train moves backwards . 2. When on a plane taking off, at first you can feel the upward motion, but when they reduce the engines from max power, you get a sensation of falling even though the plane is still climbing or levelling off

[@FlyByMax]

Good examples!

[@jocelyngray6306]

This helped me to imagine what flying in space with a rocket pack could feel like. In space, you'll feel like you're in constant freefall, because no forces will be acting on you. If you start to accelerate in one direction, you'll start feeling a force that could be felt as down. As you accelerate faster, that force increases and rotates.

[@nibblernibbles3205]

Excellent explanation and graphics! Best video ever on this topic.

[@MajorLazer182]

This was very well made, adressing a very specific niche but really intriguing

[@FlyByMax]

Thanks!

[@Republic3D]

I already knew this stuff, but it's fun to see such a great visual representation of the physics and math behind it.

[@brandonb417]

This stuff with the washout is what causes CFIT (Controlled Flight Into Terrain). It happens in the dark or clouds. If the plane starts to slowly roll and the pilot doesn't notice on the instruments they wont feel it. Then when they do notice they try to fix it, but it feels like they're turning in the opposite direction. They can't merge the feeling in their ear to the gauges. Pilots that have CFIT will believe their ears and not the plane. They end up turning tighter and tighter, not understanding what is going on, and lose altitude because the lift component keeps shrinking. Pulling up only makes the turn tighter, making the problem worse. The whole event doesn't take that long. And all because of slow roll rates not being registered by the inner ear. Cool for a simulator, deadly in the real deal.

[@bricaaron3978]

I don't understand how a person can not feel himself falling out of the seat. When a plane rolls, there is essentially no acceleration involved --- i.e. it's the same thing as tilting the floor underneath the chair you are sitting in. In that case you are going to tend to fall out of the chair unless you deliberately lean in the opposite direction of the tilt. At any rate, if it is an issue of not believing the instrumentation, a cheap solution would be to hang something --- a necklace, a pair of "fuzzy dice"... If something appears to be defying gravity, you know your assumptions were incorrect. Better yet, have such a pendulum integrated as a mechanical indicator.

[@brandonb417]

@@bricaaron3978 Typically when CFIT happens its when there are fewer visual queues, IFR or at night. Having some internal visual queues might be helpful. Also, as far as I know, usually CFIT happens to VFR pilots since they don't have as much training to rely on instruments only. IFR pilots are trained to believe the instruments.

[@bricaaron3978]

@@brandonb417 *'Also, as far as I know, usually CFIT happens to VFR pilots since they don't have as much training to rely on instruments only."* That makes sense.

[@eljaibas16]

​​@@bricaaron3978the thing is that you won't feel like you are falling off the seat. Let me put it this way: when turning in a car, the car doesn't roll. And you slide off the seat to the opposite side that you are turning. Trusting a pendulum to see the centrifugal force would be ok (we've seen this on air fresheners that hang of the mirror). Now turning in a plane it's different since the plane does roll, imagine the pendulum in the car while turning, it's pointing to one side, right? Now imagine the car slowly rolls while turning (like a plane), the pendulum points maybe 45°, but also the car (or plane) has rolled 45°, meaning that the pendulum now points to the floor of the aircraft, not ideal on IFR conditions. Also that's why pilots don't feel like their sliding off the seat Now I understand that you meant the feeling at the point of rolling, not when already turning😅.

[@avwie132]

This is amazing… this is literally what I graduated on AT the TU Delft, with the Simona Simulator. Motion cuing fidelity for a B747. Modelling the semi circular canals and the otoliths of the operator. Good times

[@edmoorebsc]

Really interesting. Presumably it's conceivably possible for the pilot to put in a series of inputs that the simulator controller cannot achieve all of them and still have time to 'washout' back to a neutral position allowing 'spare' hydraulic travel... how often does that happen and how does the controller decide what to prioritise?

[@gabrielvillar966]

In fact the one of the most important discoveries that helped Einstein develop the law of general relativity was the principle of equivalence, which says that gravity is an acceleration, not a force, in such a way that if you subject a person (in a vacuum) ) at an acceleration of 9.8 m/s^2 you will feel the same as if you were on Earth under the effects of gravity

[@Axel_Andersen]

I thought for decades that it is true that acceleration is indistinguishable from gravity. I only recently understood that this is only true for point observer. If you have observations from two or more locations then you can tell the difference because gravity changes as function of distance and for rigid body the acceleration is all the same everywhere in that rigid body.

[@HiT3ch_]

Outstanding material! Thanks and keep up the good work!

[@FlyByMax]

Thank you!

[@hyunyeelee1336]

This channel deserves a lot more subscribers

[@mishaschweitzer8083]

Great video max 😉

[@FlyByMax]

Thanks ;)

[@racheltyrellcorp9694]

Thanks a lot for this video ! I always wondered how those clearly limited range actuator could give a realistic immersion for pilots that should clearly know the real deal already. Now I know, the explication is passionating, and it gives an even better and deeper comprehension of the gravitation/acceleration equivalence ! Great work !

[@FlyByMax]

Thank you!

[@S_Roach]

While watching your video I had a thought for a way to add more realistic "g" forces. A weighted, hydraulic, "haptic" vest. Or maybe even a jacket with sleeves. Add heavy fluid to bladders on the vest when the pilot should be feeling heavier, because the total forces add up to noticeably more than 9.808m/s^2, and withdraw it when the pilot should be feeling lighter. Operate with a little fluid in the bladders, as a baseline, so there's some range to go into when going into a dive.

[@colorado841]

Can it simulate the force of the seat pushing the pilot into the controls?

[@FlyByMax]

Good question! Yes, the platform can pitch down to give the feeling of deceleration in level flight (like braking in a car). In this case, the straps/friction of the seat will exert a force that pulls you backwards instead of forwards. Thanks!

[@douginorlando6260]

Cue onset is critical. (Get the perception started) Cue conflict is critical (especially the visual vs vestibular) Selective cue disruption can actually complement the perception.( my own theory. Flying close engagement fighter maneuvers with lots of rapid turns climbs, dives, vertical loops; the 6 degree of motion platform can not fully replicate but the immersive display (270 degrees horizontal 8 collimated display panels of a dodecahedron) is the compelling orientation cue. A G-seat which pushes you around in the cockpit seat is supposed to provide a gravity cue by making you sink into the seat during high g manuevers or lift you upon the seat during zero G, but it mainly disrupts your “seat of the pants” sense of gravity. By disrupting your sense of gravity direction in the simulator, it disrupts the cue conflict between actual gravity and acceleration vector forces being simulated thereby eliminating the cue conflict.) In the heat of intense excitement and intense focus of attention on the dogfight, the 6 DOF motion system provided little benefit. The fully immersive collimated display was the overwhelming cue especially when the g seat disrupted the “seat of pants” sense of orientation. At one point the motion platform system shut down in the middle of a simulated dogfight when a moog valve limit switch was triggered. The jolt of the platform when it settled to its resting position was a momentary distraction but the lack of motion was not even noticed until later. (Total visual immersion in a display that looks infinitely far away plus the G seat disrupting the sense of gravity plus intense focus of attention on the training task made a compelling simulation. The 6 Degree Of Freedom motion does help sometimes like initially establishing reliance on immersive visual cues and not noticing a cue conflict of visual vs sense of gravity, when nose down in idle with speed brakes out while following an aircraft in a vertical dive but careful not to end up in front of the other aircraft, the 6 DOF motion does make you feel like you’re falling forward out of your seat & held in by your seat belt harness, sense of acceleration when kicking into afterburners, roll rate changes when rolling 30 degrees to look down underneath the aircraft, Real time training Simulation provides two benefits, 1… realism which equates to better transfer of training skills learned in the simulation to real world 2… cues necessary to perform the training task

[@purrple.shadows]

Excellent explanation and video.

[@Jason.W.]

We need a home version of this with VR headsets.

[@quinncide]

Motion platforms for home sims already exist (of various quality and fidelity). You’re looking at a five figure entry price for something off the shelf with 6 DOF, but as with everything, there’s an active DIY community that will get you there for cheaper (and *a lot* more work and time and maintenance requirements).

[@Soarbywire]

DOFReality sells 2DOF for under $2000.

[@GodzillaGoesGaga]

@@Soarbywire $1K per DOF axis basically.

[@gaik509]

I have never been close to such fine engineering (although I would really like to try something like that). I am not a pilot either, but it was explained so well that even I understood it. Thank you very much

[@brettany_renee_blatchley]

Acceleration & gravity feeling the same is why sometimes we cannot accurately feel what the aircraft is doing. That's why we learn to read and trust our basic flight instruments.

[@Evolixe]

I noticed how simulators used to work and figured this problem had to exist. Its good that we're coming up with solutions, may it help our pilots keep the skies safe ✌

[@sih8283]

A single point that irks me regarding the carrier accident... A pilot would use the relative movement of the stick as a reference point. You can feel how far you have pulled the stick back and how much you have pushed it forward without any visual feedback. i.e the pilot would have felt that he pushed the stick far more forward than he had pulled it back (due to humans innate spatial awareness of their limbs). Additionally, the physical resistance of the stick's hardware mechanism would be another 'input' used by the pilots 'algorithm'. Brilliant video!

[@nicolacasali8304]

That's pretty much what my DIY Stewart platform does. I have the outside world obscured by a VR headset. It can replicate a sustained longitudinal acceleration and deceleration up to 0.5G. It feels pretty convincing. I was inspired to build it after experiencing the motion platform at the RAF museum in Hendon about 10 years ago.

[@JeronimoStilton14]

You should post some footage about it, I for one would be interested to see it Edit: Nevermind you already have some, I shall give it a look

[@leopardtiger1022]

Top class scientific explanation. Simply impressed with the contents of this video. THANK YOU.

[@FlyByMax]

Very kind, thank you so much!

[@eh42]

acceleration vs velocity is another weird sensation. Try this in a car with a manual gear box: Get the car traveling backwards at a decent speed - now, shift into first and by just feathering the clutch and gas (no brake), get the car to slow down, stop, and start traveling forward. If you are smooth enough, and your passengers close their eyes - they will have no idea when they have stopped going backwards and started to move forward! They will be unable to feel the change in direction or the brief / instantaneous moment of zero speed/being stopped.

[@Marbforest]

Omg the Video make so Sense and the end just make this all Even bettttter

[@FlyByMax]

Thanks!

[@genegroover3721]

Awesome job explaining the truth. Keep up the good work!

[@FlyByMax]

Thank you :)

[@babstar99]

Great video and explanation. Modern simulation feels just like the aircraft, at least for Jet transports. Just one additional thought about somatogravic illusion is not only do you lower the nose to compensate for the perception of over pitching, with a takeoff thrust setting, the lowering of the nose further exacerbates the illusion by increasing the acceleration. Unfortunately I knew a couple of people killed by this phenomenon taking off from a dark remote airfield at night in a high powered piston aircraft. This is the typical scenario, dark night, high acceleration. Any night takeoff, even after 30+ years of flying is still locking onto the attitude indicator, the sensations still make you feel uncomfortable.

[@EvanG529]

In my opinion, using the tilts to simulate acceleration are easy to understand. The fascinating part is how the simulator decides to wash out the signal in order to maintain the same position. The sim can't reproduce forces exactly due to these restraints, so it's cool to see how it compromises accuracy with practicality.

[@mekkler]

In a constant roll angle you should feel an increase in felt g-force, which you never will in a simulator. Also you wouldn't be able to do the cool dive and climb in a parabolic arch zero g maneuver. These are the first things I would check if I climbed into a simulator.

[@DreamOfFlying]

Same

[@Pandurris]

Excellent explanation! I've worked with FFS almost 15 years from different manufacturers (CAE, L3H, Redifussion, Redbird, some custom machines) and this is a simple but accurate form of describing how the Sim tricks you. There's a book called "principles of flight simulation" which explains in detail and with a lot of formulas how a Sim works if someone is interested.

[@kevinsnell1622]

Many questions answered. Thanks!!

[@FlyByMax]

Thanks!

[@kevinsnell1622]

I wasn’t aware that the view on the screen was adjusted and panned alternately to the pods position. Mind blown.

[@alfaandn]

when you used to fly VFR for a long time, then took the instrument course, the first time you find yourself flying at night with only instrument to guide you is scary as hell.

[@siebrenlemmers4581]

Oi, great video Max!

[@AmaroqStarwind]

Since this simulator is for research purposes, you could add BCIs to the mix to measure brain activity and get a more complete picture of what's going on.

[@prasad_yzf2002]

How do u simulate forward acceleration more than 1g by tilting the simulator?

[@AndyWhite]

Great video - may I suggest a part 2 that focuses on the complexities of the visuals and the collimated display? Having seen it I can tell you this is one of the biggest changes you'll see between professional and nin-professional sims...

[@AndyWhite]

To give some context to those unaware, a collimated display allows your eye to focus in the distance - this has to be experienced to fully appreciate but it's the difference between looking at a far away object on a TV screen a couple of feet in front of you and looking at a far away object out the window. It gives depth to the image and increases the immersion considerably. It also reduces parralax error (which, if using TV screens for simulator visuals) would mean the view would only be correct for one of the two cockpit seats, not both. This is not the case with a collimated display because the focal point is so much further away.

[@xeldinn86]

Collimated displays are super expensive which is one reason these cost so much. It would be cool to try one of these sims. Or eventually get it relatively affordable to have at home.m

[@0x0michael]

I'm working on some motion sickness research for VR and these are hilariously similar it's about matching perceptions not movement