MIT Private Pilot Ground School 2019, F-22 Flight Controls

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What astounds me the most about the F-22 is a quote from (I think) the FPP about how such incredible eyewatering performance was the least impressive thing about the plane compared to its systems and stealth capability.

👍︎︎ 20 👤︎︎ u/loonsy 📅︎︎ Feb 13 2020 🗫︎ replies

I thought I would preview this and maybe watch it later. It took about five seconds before I forgot to stop it and here I am just finishing it. Awesome video with excellent info.

Thanks for posting this!

👍︎︎ 6 👤︎︎ u/Morstraut64 📅︎︎ Feb 13 2020 🗫︎ replies

Omg thank you so much for this!!!

👍︎︎ 4 👤︎︎ u/the_fake_civ 📅︎︎ Feb 13 2020 🗫︎ replies

Thanks for sharing. I appreciate it

👍︎︎ 3 👤︎︎ u/This_Permanent 📅︎︎ Feb 13 2020 🗫︎ replies

awesome. i love how an MIT seminar can't figure out how to mute their youtube vid lol

👍︎︎ 6 👤︎︎ u/RotoGruber 📅︎︎ Feb 13 2020 🗫︎ replies

My takeaway: it has an A2A refueling mode to make your life easier.

ED: WHEN?

👍︎︎ 5 👤︎︎ u/Maelshevek 📅︎︎ Feb 13 2020 🗫︎ replies

The F/A-18E/F/G all do similar things with their flight control. However the F-22 is more refined ergonomically and has better thrust to weight and thrust vectoring.

👍︎︎ 1 👤︎︎ u/SnipeUout 📅︎︎ Feb 14 2020 🗫︎ replies
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well guys you have picked the coolest independent activities period class you could ever do with ground school this is the most awesome thing possible when I saw the course offerings so kudos to Tina and Phil for teaching this this is a good good gig I go by Laz it's a fighter pilot thing all fighter pilots have call signs they're not like what you see in the movies by the way Top Gun is the worst movie for any fighter pilot to watch it's terrible drives you crazy no one is called maverick because they're the most awesome thing on the face of the planet never happens that way you're always named for something silly so the previous discussion about crew resource management if you're single-seat you still have air traffic control you have other guys I am living proof that that's 100% true so I will get into it too much but suffice to say if you know the biblical story of Lazarus you know a lot about how I got my name and I'll leave it at that normally that's over beer afterwards so we're here to talk about f-22 flight control stuff I'm gonna give you the punchline right at the start I'm here to tell you that everything you're learning so who's actually flown airplanes here already like sailplanes so a lot of guys right so a lot of guys so first time then 4pi of the other half of the class or so so here's what i'm here to tell you the same stuff that you're learning with respect to Cessnas and all the stuff with respect to the ground school there's no difference between this and between my beloved raptor it's the same thing so there's great relevance and you as MIT guys have the ability to derive and figure out what makes the Raptor look the way that it does and we can talk a lot about the flight controls it's not cosmic we can go through that so with that they always have the standard personal background slide here's a gig I'll keep it really simple I am a test pilot which means I am a fighter pilot and I'm also an engineer it means I like beavis and butthead greatly and I read Carl Sagan it's the same thing to me so as a fighter test pilot you live in the world of being a fighter pilot but you also have the ability to understand MATLAB and to be able to do cool neat MIT ish kind of things because all of the stuff that you're working with as a test pilot or brand new things new weapons new avionics new airplanes in some cases and that's not the world of a fighter pilot fighter so exceptionally good at taking this airplane to combat and doing the normal kind of missions with it but when there's something new on board that requires an engineer so I have a deep deep connection with this institution I graduated here finished up here last year in 2018 I've been a whole bunch of other kind of funky stuff along the way to combat tours that was a lot of fun I'll tell you flying is one of my great passions flying and getting shot at and missed is my second great passion that's much cooler and then when you can fly and you can use that airplane to actually protect people from bad guys that's that's that's life fulfilling right to go get a chance to go do that so we can talk a little bit more through that as well test pilot we get a chance to fly a lot of different stuff so you'll see this 76 different airplanes that might sound weird to kind of the rest of the world but in the world of flight test that's pretty normal and the reason that's there is it's just like look so I by the way warning right to the class I talk a lot in terms of movies alright Game of Thrones shows or whatever television shows and sports because no matter where you come from those three topics always tend to bring everybody all together so it is just like what you've you know when you've gone car shopping and you sit in this car and go ah man I really like this way the steering wheel feels but I hate the way the radio is set up and you go to another car and you go ah man this is great from a you know from the sunroof whatever but this stinks that same kind of discernment that you have when you're shopping for cars you know the this airplane is a couple hundred million dollars you don't want to be wrong about that and so you want your test pilots very very experienced on a lot of different airplanes so I've got a chance to fly helicopters or spectacular in pilot training I don't know why but we send our worst pilot training students to helicopters it's the dumbest idea because helicopters are really really challenging they go fly but we've had a chance to fly helicopters your discussion Tina earlier about right away I was laughing with that because I flown a Zeppelin an airship it it's quite spectacular it's a big lazy boy couch with a big trim wheel and big engines that actually pivot on the outside so you can turn the whole ship based on that that's pretty normal for for being a test pilot it's getting a chance to fly a lot of different airplanes more so than just one particular airplane your whole life most of my stuff is in fighters so I've flown every frontline fighter with the exception of the f-35 hopefully I'll fix that soon shortly in a few months but a lot of stuff so MIT guy Harvard guy did some stuff it's it's been a good life really at the end of the day what I want to impress on you is I am 100% zero different from anybody in this room I just have more battle scars made just from a lifetime of doing this I started offline Cessnas I did that for several years of my life I still do it I love it fly sail planes still do it love it and all the stuff that you learned with this has direct applicability to the more advanced fighter airplanes in fact I'll tell you this is actually harder to fly than the Raptor and we'll talk a little bit more about that as we go through all right so more fun and games all right so now comes the class participation part my talks are very interactive I love kind of hearing what you guys think so we'll do a quick thought exercise I'll try and keep a mental note because I stink at writing on a chalkboard but we'll chat through this just so you can understand that there's really not that much difference from what you're learning now to go off to do something like that so why does a Cessna look the way that it does and why does a raptor look the way that it does what were the engineers trying to do and just just call them out you know real guy cheap okay so explain yeah so you brought up two things one is the position of the wings right so in a Cessna the wings are obviously well in a lot of airplanes really not just systems but an excessive the wings are directly above you big Hershey bar wing you know why do they put the wings this way in a Cessna you're doing great so far keep going man I'm how many answer that get get in or out of a cirrus in the heavy rain and you will immediately see the value of that Cessna wing yeah they did this so that my wife doesn't yell at me and bad weather conditions so that you can get inside the airplane with not getting completely what the other part about the high wing is it's great for visibility looking down right where this is terrible is if you're turning and you have to be able to see through the wing because you're kind of doing the old you know looking over the side to see kind of out the outside so that's one advantage right of where Raptor right it's not a high wing or a limb it's kind of like a mid wing if you will but wing is well after the cockpit for what reason visibility yep that's that's the big huge reason why and then you also brought up the idea of the swept wings all right why the swept wings compared to say straight wings okay what's that what's what's that advantage close close I'll stop picking on you because you're a bold and went first go ahead yeah mock so explain mock like the first jet airplanes that came out the wings on the jet airplanes had wings that looked exactly like this and that was a problem I'm gonna do something I thought I wouldn't try to do but I'll try to do it so here's your swept wing right here's the air as it comes over the wing right and then what ends up happening is really what you care about is the air that's going over top of the wing that's normal to the cord line of the wing itself you know what I mean when I say cord right just like this imaginary line so on a Hershey bar wing all of that air hits the wing and it goes directly over top of that cord line of the wing so like when we talked about over here the wings have camber so what happens to the air as it goes over top of any wing doesn't matter if it's a fighter wing or whatever else but what happens to the velocity of the air as it goes over top it goes faster right so if I'm already going fast and air hits my wing and goes over top of my wing and goes faster than the rest of the airplane that's gonna cause a problem when you get to very high speeds approaching Mach because when it's up happening is you'll get a shock wave forming on that wing and the moment you get a shock wave form in there that's like a big brick wall to the to the wind and that causes all types of drag down stream slows down the airplane all types of things so what they found is I can sweep the wing right when I sweep the wing some of that air is normal to the cord line so if this is like the yousa lives over here and here's the wing and it comes back over here some of that air is gonna be that way and some of that error is gonna actually go out and go go span-wise if you will like this so I'm trying to draw this correctly to get the to get the right angles but you kind of get my point so some of that air goes span-wise some of the reasons why you have wing winglets right to present prevent some of that drag that happens up the winglets but then also what you're worried about is rather than the full component of this wind you're only worried about the wind that's normal to the flow of the way the cord line is set up so that's why they sweep the wings right okay so what else why is the Cessna look this way why does this look like that good stuff payload is an important thing let's talk about the payload for a second actually we'll talk about stealth since you brought it up so look at that plan form and what do you notice with regards to stealth all angles all right that angle that angle that angle yeah no right angles so the reason is and I'll do my high-tech pizza you know eight here right so whose EE in here anyone ee for MIT okay so if you're a beam of radar energy you love this right you love when you have a nice flat thing directly to reflect so all that radar energy you put at me goes right back at you right now what happens if i take that panel and i go like this a little bit right so yeah there's not so much now I'll really mess up your mind what happens if I do that right and now you have to start dealing with angles and edges right raptor is this constant fight between the double e guys and the aeronautical engineers when you make an airplane like this and you make angles like this and you make it there's no right angles or whatever else like that you're exactly right a greatly reduces to stealth now this is not Wonder Woman's airplane it's not like you just become invisible and no one can see you but it's very very hard to see on radar but there's a challenge in that because when you make an airplane that looks like this which the EE guys tend to like the Aero engineer guys tend to hate because it makes the airplane unstable so we'll talk about that this airplane very very stable very very stable okay what else a couple other things so why is the Raptor looked this way why is a Cessna look this way good titanium hole types of stuff right so this is an airplane people buy commercially if you had if you were Jeff Bezos so you would never purchase this airplane this because it is hyper expensive my jets were test Jets which means they were very different almost like hand-built custom f-22s each one three to four hundred million dollars apiece scary alright in terms of how much it actually cost the canopy on this thing probably worth more than about ten of these kind of all put together the payload part you brought up payload two so the other part about the stealth you can see here I've got doors so there's a big main weapon bay door big 17-foot doors if you will and then there's doors on the side that come open here unlike a Cessna I mean we talked about you can 14 ago actually disappeared the dropped object drop in pumpkins my pumpkins are a thousand pounds come off the airplane just like that different missiles and different bombs or whatever the center of gravity of the airplane is right about where my finger is and so I have these weapons that are here that when I release them it's suddenly like dropping a car off the front end of your airplane and so there's a huge center of gravity shift that happens just like that and so the flight controls need to be able to compensate for something like that last piece I'll give you just for sake of time is what's the speed envelope if you will that this airplane kind of operates what I wish you hungry man I wish 200 I would buy one right now if I could go 200 in the city yeah I mean on a good day right you might get you know if you get a really really high-end general aviation airplane 160 knots or so something like that you can get more than that but then you start getting this some real like mercedes-benz exotic class kind of general aviation airplanes that are like the Cirrus that go beyond there in general you're talking somewhere between 80 and about a hundred and forty hundred and fifty for most of them or something like that this airplane believe it or not this airplane can actually fly as slow as the Cessna but it also can fly two times the speed of sound and it does that pretty easily believe it or not also this airplane sixty degrees of banks starts to get really extreme a little bit uncomfortable this airplane fully aerobatic doesn't care pulls nine G's you guys know what G's are the accelerations of gravity so everything you know my human head well MIT MIT heads weigh about twenty pounds or so a little bit more than they than the norm so at nine G's everything on your body weighs nine times as much so that's 180 pounds with your neck has to be able to support that imagine everything on this airplane has to be stressed such that it can tolerate that load and more I also can go negative G as well altitude wise I think the highest I've ever had a Cessna was about fourteen thousand feet and it was wheezing it was really really hard for it to get up there this airplane goes zero feet all the way up to about sixty to sixty-five thousand feet so it flies twice as high of what you would see on your commercial airliners what I'm trying to impress on you is it's a huge flight envelope with a very different solution set compared to what you might have on a Cessna the only other thing I would say with Raptor is and this was something it took me a while my first combat mission I really understood this in a Cessna if I have a problem I can land and most likely people will come out to help me and call home and everybody know I'm okay in bad guy land if people are coming to get me there they really are coming to get me so you're in very hostile territory where you do not want to leave the airplane if you can avoid it so there's a trim this amount of redundancy that's kind of built into this airplane will talk more through that a little bit so anyway you've essentially derived all of the challenges that a flight control engineer would have to deal with let's talk a little bit about I'll put this here just for sake of making it easy to rest this airplane has what's called reversible flight control system what does that mean you guys talked about that yeah god yeah it's not only when you move the stick what happens if you go outside the airplane grab the aileron move that up and down what happens inside the stick moves right so it's reversible right so I move the stick and the flight control surfaces will deflect or I move the flight control surfaces and the stick will deflect so they are directly connected with pulleys and cables to one another for the guys who have flown what does the airplane feel like when you get to 100 120 130 140 miles an hour I mean you're really getting what does it feel like on the control surfaces yeah a lot so it's heavy right gets real stick kind of heavy same thing if you're slow everything gets kind of sloppy if you will and very because you are directly feeling the air loads on the airplane as transmitted to the stick in this airplane these flight control surfaces this this tail surface back here is about the size of a lot of fighter wings it's huge and you can imagine at 120 130 the airplanes really hard to really move well what happens if you're going 1,000 miles per hour you could be Arnold Schwarzenegger you do not have the strength to maneuver these controls around so this airplane has a very very exotic hydraulic system and a computer system and an electric system that allows all that to operate from the hydraulics I'm not kidding there's like 4,000 psi of hydraulic fluid that moves this whole thing around swings it back and forth from the electric standpoint now again this is a reversible flight control system all manual the flight controls in this airplane don't work unless the electrics are turned on to go do it so your flight controls are electrically controlled hydraulically powered but electrically controlled which is a little weird when you think about it because now all the sudden electrical problems in this airplane start impacting your ability to fly the airplane which gets a little bit strange you guys ever hear of a thing called a permanent magnetic generator do you know what that is a little bit of a technical term who knows you know a lot go ahead yes you have correctly derived the definition of a permanent magnetic generator now the way it works is this airplane has six permanent magnetic generators they are the primary source of flight control power all that has to happen is the engines have to rotate that's it so even if the engines are shut down I can just keep wind going through the engines and they rotate they will rotate sufficient to generate power from the permanent magnetic generators if those fail the airplane also has electrical generators on board there's two of them there's actually three of them on board they can power the flight controls as well worst case scenario for a raptor pilot the engines seized up I lose my electrical power the only thing I have left is a battery and just like anything else battery the more you use it the more it depletes so at that point any deflection of the flight control surfaces depletes the electrical energy and you don't have that much left to actually control it okay one last thing here we'll move on to the next slide we'll talk a little bit some just some definitions the wing has this thing on the front you know what that is what that's called leading-edge flaps right okay perfect all right what's that called ailerons now what I hear I heard something else who said that okay explain which apply you you're in you don't have full details control services or part of it is that I can't get any Platt for the partying yeah standing that's good and this airplane this airplane has what ailerons right so if I want to go right and I move the yoke right what happens to the ailerons here in this airplane sorry I'll put it that way that way you're setting up so I'm going this way so this aileron is doing what going down right this aileron is doing what right so I'll cut to the chase these are ailerons these are flipped so these are the flapper ons here in the inside these are the ailerons in a raptor those ailerons deflect differentially so just like you have an assessment they can also both deflect up they can also both deflect down the flaps on the inboard are flaps and ailerons flapper ons so they can deflect up and they conflict down will show why that brings up some neat stuff okay rudder obviously back here in this airplane when I push the rudder left the rudder deflects left I deflect right this has two rudders both rudders can deflect one way they can deflect the other way they can both deflect in and there's some reasons why you'd want to do that and they can both deflect out the last piece I'll give you is back here normally this would be called an elevator but on a supersonic airplane we call these horizontal stabilizers if you guys have read the story of the bell x-1 so Chuck Yeager when he went supersonic we talked a little bit earlier about supersonic shockwaves forming on the airplane as you start going fast what Chuck Yeager discovered is that the elevator like in a traditional Cessna that horizontal stabilizer does not move so the elevator at the back moves but the horse but it but this part stays fixed that shockwave that would form right here would actually blank the air back to the elevator and they wouldn't have any pitch control so when they talk about this thing called Mach tuck which was a scary scary thing that happened to a lot of World War two fighter pilots when they got into a dive they would start forming shock waves on the airplane they didn't have the elevator authority to pull up so they would actually nosedive all the weigh-ins because they go faster and faster and faster heading down the answer was rather than the back end of this thing maneuvering the entire surface moves so as a fighter pilot especially when you got people walking underneath the airplane because their maintainer czar working on things you always always always you show them your hands because if you tap that stick again the stick is not directly connected just like it is the stick is connected to a computer the computer votes and it allows things to happen it then commands a four thousand hydraulic psi system to deflect basically there's big old wing you can actually take a guy's head off with the flight control surfaces so you always always show your hands whenever you have people walking underneath the airplane for that so it's got a very very advanced flight control system on board we'll talk through a little bit about what advantages that kind of gives you last piece I'll give you is the engines at the back which are a thing of beauty I was a propulsion guy aeronautics engineer kind of thing it's almost like modern art masterpiece to me those engines are have the ability to call what's called thrust vectoring they'll swing up and they'll swing down where would you want to use that why does he why do the engines have thrust vectoring you've answered a lot Maggie you're smart though you know what's going on good where's it where's another regime think of the flight envelope of the airplane very high altitude so why high altitudes density goes way down as you go up in altitude so if I deflect this I mean I have to get more deflection to move that air to be able to move the airplane if I'm relying just on the Aero surfaces alone the way I get around that is I put two thirty five thousand thrust pound engines if you will onboard the airplane and just like a fire hose with I grab a fire hose that I move it you would feel that torque on your body the same thing here with with the thrust vectoring on the back so with just the movement of my hand I can deflect seventy thousand pounds of thrust way at the back end of the airplane so we talked about center of gravity being right about here so that moment arm of that thrust force is all the way back here and I can do like that up and at very very low speeds where the flight control surfaces might not be doing well I can still move the airplane just by using the thrust alone at high altitude where I don't have a lot of density same thing I can maneuver the airplane just by using the thrust alone so where that helps you because again this is a dog fighter here's what happens and you'll you'll see this from time to time so I'll do this a bit the side look when I get to high angle of attack so the wind is coming like this and it's hitting the bottom surface of the airplane I don't have the ability to really maneuver a lot because sometimes some surfaces are blanked by just the size of that fuselage coming right out into the wing so I keep if you will by using the engines to get that final little pitch rate we'll see later on in the Raptor demo video where the airplane will go it's called a high alpha loop high angle of attack loop it'll go vertical and rather than doing like a loop where you see it prescribed this whole path over here the airplane will go vertical I'll engage the thrust vectoring and it'll pivot so the velocity vector is still heading straight up so the airplane is still moving up but it kind of does this gymnastics thing where I've now turned the airplane using thrust vectoring even though the airplane is still heading straight up it's wacky it's totally cool alright alright let's talk through a couple other things okay so that's the flight controls how we doing time line okay we're looking pretty good okay anyone recognize the cockpit on your left at 15 yeah outstanding good this was my very first airplane I didn't know any better right i sat down and said wow what a cool cockpit look at all these cool stuff buttons everywhere and switches all over the place this is an airplane of the seventies designed when richard nixon jimmy carter that kind of era if you will very very first intro to solid-state electronics really wasn't fully fleshed out at this stage this airplane had a hydro mechanical system which meant that just like in this airplane where there were cables and pulleys the similar kind of flight control system in it there this picture is the Raptors cockpit on the inside some pretty dramatic difference is between the two so again just call them out what do you see laptop where does that help you good oh yeah it's great you see these new digital mercedes-benz and BMWs or whatever where like in the old days you just had you know speed and attack if you will now you can configure it however you want now these become the moment you start putting that in there I get this to work there we go now got it yeah the moment you start doing stuff like that you start creating a software airplane which gives you a lot of flexibility and a danger right we'll talk about that one a little bit later on what else EC flight controls license we're talking mainly about flight controls today sidestick yeah so great there is the control stick in an f15 sits directly between your knees in a raptor that is your control stick it's on the side why would you ever want to put something like that on the side go ahead that's part of it that helps and there's actually you can't see it here it's partly there but kind of this little section here it's a fold-out armrest so your wrist is on the stick your your elbow is if you will it's resting on an armrest so it gives you a lot of leverage from there that's one reason what's couple couple other reasons why you'd want to go side stick vices center stick legs get in the way that's a big deal because in this airplane you actually got got pretty good after a while flying it where if you really need to maneuver the stick you kind of do the leg up and move over that way to get everything out of the way the other side about it too it might not be quite so obvious but you see how that stick that's about where your eye height would be you see how that stick kind of gets in the way of seeing some of the instruments so it's just sitting right there right and a side stick that's completely off to the side and all of this real estate is completely open the other thing I'll give you again just for sake of time it's it's a little bit of a thought change when you have a center stick it's like when you're driving a car and when you're at parking you know you're trying to park your car you want to be able to maneuver that wheel around a lot but when you're at highway speeds if you were to take the wheel and maneuver it that much again you're gonna roll the car so in a center stick you move the stick around to be able to deflect the flight control surfaces there's a physical displacement of the stick to make that happen on a side stick that stick initially when they first put it in did not move at all so imagine if you were in your car and you wanted the steer and rather than the wheel actually moving you just put pressure on the wheel itself and that was enough to transmit to the computer in the car to turn the wheels that was a problem initially which we can talk about after the presentation that's a little bit of a sidebar discussion this is a human factors thing it's a side stick initially it didn't move eventually they decided I'll put in some deflection so I can go a half inch left a half inch right about a quarter inch forward because normally you know I go about a half inch back because normally I really want to get the nose going this way if I had that much deflection for it I don't want to fly the airplane this way so you have the ability to do that but it gives you a little bit of the best of both worlds there's some deflection to give you feedback that you've input something on the stick but not so much deflection that it kind of gets in the way of everything else you're trying to do so there's a limited real estate and a fighter cockpit the last piece I'll give you in us a little bit hard to see here is all those buttons there on the stick you know what you have the ability to do so it's it's exactly like modern cars car steering wheels right now you can control volume radio everything else like that you can do it from the steering wheel same thing in a fighter it's called hands-on throttle and stick HOTAS and it allows you to control everything that you would want to do on the airplane with never having to leave your your hands from the throttle on the stick the other piece I'll give you is that in a raptor so in a fighter like this this is your stick this is your throttle in a raptor because the flight control modes can change so much this is your right Inceptor this is your left in scepter it's all considered part of the like control system alright let's keep going so just like on your car where if you want to go to XM radio you go to media source or whatever and go XM satellite radio you have buttons because it's a software driven jet just like we saw before and I can pull up a flight control display that shows me the position of all my flight control surfaces again the pilot is way forward on the front end of this airplane as I deflect things sometimes I can't actually see them and so initially this was a flight test display so but I don't have to do the old poltergeist thing and try to rotate all the way around and be able to see to the back end of the airplane to see if the elevators moving I basically instrument everything and I can see it here now some of the human factor stuff that's kind of cool with how they did this so this right here so again this tells you at the top rudder deflection surfaces ailerons where the horizontal stabilizers are at how the engines are doing this is a little weird I don't really like how they did this one but this is the leading edge flaps le flaps or lavinia inch flaps so it just shows you how far they're deflected dug in dug down on the lower left-hand corner it shows you center of gravity so there's limits just like would you you know what you would normally do on flight planning for your Cessna hey I can only put this much fuel with this much passengers and I got to be within this limit for takeoff for landing and everything else the airplane tells you that now what's cool about some of the things they've done in Raptor is that if it's out of limits again it doesn't expect you to get out the piece of paper with the whiz wheel in the e6b it just changes color and it goes red and it gives you a warning right and it says hey idiot you are beyond the aft center of gravity no gauge tells you it's just having a hard time seeing or all the fuel is and everything else that's a different story but it tells you where what percentage of mean aerodynamic cord that you're sitting at and it's able to adjust stuff around so I'll give that to you because what this allows is oh by the way the last part here is flight control so in other words this tells you where you've moved your stick and it tells you trim so you know where the trim is set and also tells you where the stick is set so you know your inputs that kind of go through there when you have a software driven machine you can customize things and make it very simple you guys have seen that terrib-- terrible awful movie Top Gun right it's just awful right so that scene where maverick loses his engines and they go through this engine one is out engine two is out and they go on this flat spin to see which is a bunch of BS when you're in a spin you don't translate over the ground you fall straight down so this whole flying out to sea thing is ridiculous it doesn't happen that way in if you don't have a software-driven airplane when you lose engines like that then you've got to go through this hole it's like in for instance in the Cessna if you lose a motor lose the motor what do you got to do right establish your glide get everything set up check to see am I left right or both on the fuel source what's my whatever blah blah blah and everything else in the Raptor it's the most awesome thing possible you literally do nothing you sit there and the computer goes oh you've lost the motor I've noticed that you have a problem let me see if I can help you and it'll restart the motor for you if it can right if it can't restart the motor chances are it ain't gonna restart and you can just leave it shut down if you will it allows some neat human factor designs because in this airplane in the Raptor believe it or not when you're flying the Raptor you're not thinking about flying the Raptor you're thinking about employing the Raptor so you're trying to find where all of your wing mates are where the bad guys are at cetera et cetera flying is secondary whereas in this plane flying is everything so they tried to as much as possible alleviate the pilot from as much burden of responsibility of thinking about flying the airplane by doing kind of neat little tricks like that the other thing I'll give you too about the flight controls is again we talked about how ailerons can go up a Lorenz can come down flapper ons go up and they go down rudders come out go down on takeoff mode I'll show you something kind of cool so here's the nose look on here on takeoff mode without any input from the pilot so there's no flap switch in the cockpit there's no leading-edge there's nothing there's nothing like that it just knows based on the fact that you've got the gear handle down and that you're on the ground then it senses the weight on wheels that thinks this guy wants to take off so the rudders will both deflect inward why would you do that good so um not quite there is a tie between the flight controls oh so in other words if I take the rudders and I towed them both in so both rudders are deflected in what does that do from an aerodynamic standpoint which ways the nodes gonna go if these rudders are deflected in right so it makes it easier to rotate the airplane on takeoff because the rudders are deflecting in both of them go in right the other part about it too is so we talked about this you guys ever see like a competition aerobatic like one of those extra 300 kind of airplanes you see how the aileron runs the entire length of the whole wing so about the pilot all they got to do is just tap the wing and the airplane is gonna do corkscrews and spirals on a raptor that's part of the reason why the aileron and the flap Iran can move together as one surface and so the leading edge flaps will dig in the trailing aileron and the chilling gets flap that will dig in as well so on takeoff with no input from the pilot whereas the wing normally would look sort of like this with a little bit of camber on it on takeoff that wing looks like this it's kind of cool like when you look at it from the side so if you're looking at it from directly side on that leading edge flap comes down these come down that puts in a whole bunch of camber on the wing and it generates a lot of lift so and again that's completely independent of the pilot the pilot has done nothing other than just tell it I'm on the ground because the gear handle is down what would be what would be a typical rotation speed yeah so that's a good question what do you guys think so I start on the runway by the way I need 8,000 feet of runway this whole 2500 feet is not for a raptor unfortunately 8,000 feet of runway but by the time I actually get ready to pull back on that stick to rotate how fast do you think it's going locals 150 is a usual usually sohbat takeoff which by the way this airplane is about 34 or 35 tons on takeoff compared to like you know 2500 pounds or whatever so it's a very heavy airplane it's got to get a lot of speed to be able to get that rotation that's about 150 hundred and 60 knots on takeoff which is like faster than like the never exceed speed of the Cessna as it goes but yeah so the flight controls are there to help you the other thing I'll show you too is there is so sailplane guys where my sailplane guys anyway fly sail planes so on the left in a sail plank cockpit you typically have a lever for the speed brakes spoilers right so these big surfaces that pop up on the wing to slow the airplane down to just glide slopes and those sorts of things we talked a little bit earlier about how the electrical engineer guys want this thing to be completely stealthy and whatever else the last thing you want to do based on the discussion we just had is I don't want to have a big board stick up in the middle of this airplane because that's gonna make my radar reflection go very very large so they did something kind of remarkable they use the flight control surfaces themselves as the speed brakes so if I need to slow the airplane down I hit a little switch on the throttle and immediately what happens is the leading edge flaps will come down a bit the ailerons will both go up the rudders will go out so they'll both tow out and it's it's using that to help slow the airplane kind of down it's actually quite effective which is pretty cool all right couple other things will go through landing mode pilots done nothing touchdown throttles are back gear handles down and all of this stuff happens here let me get this zoomed in here so that's the aileron it's up hold it crap the other ones up to the flapper on goes up on either side the rudders you can see how they're both kind of kind of toeing in there a little bit the reason it's doing that is it's trying to transfer all of that weight from the wings and put it into the gear so it's trying to kill all of the lift on the wings and transfer that to the landing gear so that you have the maximum traction on the wheels as you hit the brakes as you slow down also on refueling so when you go air refueling there's a little switch that you open in the jet that opens up this door that tells the jet that I'm getting ready to refuel while I'm airborne when it does that it says this guy isn't trying to dogfight the airplane anymore they're trying to get gas so therefore I don't need all the full role capability and everything else and really what I really want is an airplane that's really responsive with its lift and so again no input from the pilot but the leading-edge flaps will deploy down the trailing edge flaps and the ailerons will also deploy down again they're trying to create camber on that wing this is all digital flight controls no input from the pilot whatsoever that's also what would a typical airspeed be when doing this air refueling this is about whoops I'm sorry let me go back one here this is about about 300 300 knots or so something like that you got to be able to fly so for a raptor that's kind of slow for the tanker airplane that's somewhat fast so you're trying to find that marriage where both airplanes have good flying qualities so that once not about to stall and the other ones in full power trying to catch up to them by the way the most unnatural act I've ever done as a fighter pilot is to connect up my airplane to another airplane I just never got used to it I can do it just fine but the whole notion of this big boom connecting my airplane to the big airliner was just really strange and weird to me never got used to it okay some of the limiters so in an f15 because we should talk to that a little bit earlier at 15 can you can get up to five hundred six hundred miles an hour you can take both hands on the stick you can pull that stick all the way back and you will rip the wings off the airplane and he will turn it into a big ball of metal cascading down to the ground because you have over g'd the airplane again that awful terrible movie Top Gun in which Tom Cruise departs the airplane and gets into a spin again you've exceeded some capability of the airplane and the airplane departs controlled flight and gets into some type of uncontrolled situation on a raptor there used to be on the pilot operating manual a little blurb that said quote you can maneuver this airplane with quote reckless abandon and you will over gee the airplane you will not depart the airplane from controlled flight they did a spectacular job allowing this airplane to get right to the edge of performance but not going over the top so one of the neat things that they did airplanes in a left-hand turn look at that aileron it's up look at that aileron it's up what the crap is going on there and if you know this one you really do get the model because I didn't know this for a long time so again just for sake of time so no we got guys coming in afterwards center of gravity if the airplane sits right here in your engineering classes you always talk about forces acting on the center of gravity and you kind of take this whole airplane and you model it down to a point mass and you say that's what that's you know for sake of all the you know sum of forces analysis well in real life this airplane is about 43 feet wide yeah you can sum the forces through there but there's forces acting all over this airplane at different spots think about here on the wingtip I put G on the airplane and this wingtip it's almost like the wings want to bend up right as I'm coming down so you put a lot of stress out on the wingtips so their answer quite ingeniously was to deflect the ailerons down when you're at high manoeuvring the way you know you're at high maneuvering is you can kind of see these little wispies forming off the wingtips so you are creating low pressure that's another one too you can see the clouds forming on the front edge of the wing low pressure causes that air to condense and so you make clouds so you know the airplanes really maneuvering up and an answer to reduce stress at the wing tips was to deflect the ailerons up what happens to the lift out of the wing tips with the ailerons up goes down right so it helps to kind of push those wings back down again so you're not trying to over stress the airplane there are limiters like this all over the airplane such that you won't over gee the airplane you can't oh you know little you can do anything you want to the circle that's why I'm telling you it's easier to fly a raptor than it is to fly a Cessna because you really have to pay attention what you're doing an assessment in a raptor I could put my kid in there and he can do this all day at whatever speed and nothing bad will happen to the airplane it's really quite spectacular how they did that the other part I'll give you here is some of the command systems so if I'm in a dogfight and I'm trying to shoot the other guy I'm going against a manoeuvring target and so the flight controls transfer over to what's called a G command system so if I'm maneuvering at 4 G's and I let go of the stick the airplane will stay at 4 G's and if I see that the targets manoeuvring I need to go to 6 GS or seven G's I'll put that in and the airplane will keep that so in other words again it's a vote right I'm not physically connected to anything I talk to the computer and I say I want 6 G's and the airplane does all types of black magic and sorcery behind me and lo and behold the airplane gets to six to seven GS that really matters when you're in a high manoeuvring kind of situation so it goes G command when you're slower I II on landing and I want to put that flight path marker right on that edge of the runway because that's where I want to touchdown right out the thousand foot markers then in that scenario I'm not really cared so much about G command I care about pitch rate and so it transitions over to a pitch rate command and if I put no input on the stick it says zero pitch rate again black magic and sorcery will happen behind me the flight controls will do whatever they need to do to make sure that my pitch rate stays at zero so it transitions from one type of flight control system to the other no pilot input whatsoever it's just based off of flight flight command system all right so let's talk through a couple of the implications of that and then we'll go to questions at the end can you do the flight control video Raptor at the top it's about a minute and then bring it up to full screen and hit pause [Music] [Music] thank you okay and can you go back to the beginning on it real quick okay so video in cockpit facing out the display screens is a big no-no because you could see stuff so we won't even bother with that but what they did this is the Raptor flight demonstration team this is out of Langley Air Force Base Virginia they mounted a camera in the cup it kind of facing aft what I love about this is again you can see real quick kind of what's going on with the airplane so again the leading edge slats there's no input from the pilot other than just maneuvering they'll deploy wherever they need to you'll see the horizontal stabilizers and if you're close you can actually see where the ailerons are doing what the flapper ons are doing a neat trick and we'll see this as they go into this high G demo you guys know about have you this gets a little bit advanced but a thing called static margin which is a stability thing about this airplane again this airplane in its bare airframe configuration no hydraulics no computers nothing on board the airplane totally unstable what keeps it stable is the computer itself what you'll see is you'll see this maneuver where he'll go into a G turn and you'll see all the clouds forming on the back end of the airplane pay attention to what the leading edge flaps are doing they're digging in the horizontal stabilizers you'll see them initially move to get the turn going but then once established in the turn the way it's controlling things is it's moving around the aerodynamic Center and this the center of gravity it's doing that by Dorking around a bit with the lift on the wing and it's doing that by deflecting the leading edge flaps so that flight control surface display I showed you earlier the horizontal stabilizers would be completely streamlined and all of the maneuvering is coming from the wing itself which is pretty amazing no no good go to flight controls we'll watch that yep and then we'll just kind of watch as it goes through this time without the funky club music I guess [Music] or not later [Music] I know totally so at that speed again it's a G command system pilot is commanding a certain G rate and minor deflections are happening all the way here back along the back edge of the airplane pilots has no input on that the system is doing everything possible to command that G that the pilot is asked for you'll see one other maneuver here pause for a second so what this maneuver is is and again right slow speed airplanes going straight up and what they're trying to do is basically pitch forward completely and get the airplane so it's almost like you're flying an L like you're going straight up and then you want to pitch forward and then accelerate out horizontally that way the way it gets that is through that that thrust vectoring that happens but as that maneuver happens again all the pilot is doing is just doing a direct push forward on the stick watch what happens so all the flight controls in the back of the airplane to keep that airplane going exact over the air pilot wants it to play so you'll see huge deflections out of that horizontal stabilizer it's kind of neat you can keep playing so what you're seeing there is from the outside of the airplane we'll see this more on the demo is the airplane is essentially pure wedding in the sky so what's falling straight down but it's very controllable it's flying at speeds about 60 to 65 miles an hour but very very controllable and you'll see every bit of flight control surface on the back end of this airplane deflecting to do what it needs to do so don't think of it in terms of aileron elevator it's a little bit fluid when it comes to a raptor it's stuff stuff happens back there touch-and-go video ok so this shows a little bit of yeah you can go and play that and hit pause for a second we'll just do this setup okay so very quick to set up for this video this is the downside of a digital flight control system because on this airplane again it's it's pure cables pulleys right it's ratios and gears and stuff like that right this airplane it's software code its zeros and ones and you better get it right and everything is interconnected we talked about how moving the gear handle tells the flight control system something different if I open the Air Refueling door it tells the flight control something different in this case the power setting of the airplane tells the airplane something different this guy one of my good friends test pilot outstanding guys so don't think of this as he's a bad pilot he's not he's awesome but the jet believes something that wasn't really true because there was an error in how the software was coded and you'll see the first approach he'll do an approach he'll take off again in what's called military power so they're not using afterburner and the airplane behaves just fine on the next time around he goes around using afterburner power so you'll see fire come out of the back end of the airplane and that changes something in the flight system for the engines which tells the flight control computer a different condition and what ended up happening is that the gains if you will of the stick were completely off so again this would be like if you were on the highway speed and that same wheel deflection you would use to park your car in your garage now that little deflection of your wheel makes that same turn of the tires up front so you get into what's called a pilot in stop oscillation Pio which basically says you're out of phase with the airplane if I'm driving my car and I turn the steering wheel right the cars going left that's what's going left I'm trying to correct it I go right now the thing goes right and so you get out of phase with the airplane and you'll see what happens go ahead new play by the way you see all the flight control surfaces deflecting in the back this is now in a pitch rate system so he's just trying to land the airplane the back of the airplane it does whatever it needs to do to keep that flight path marker exactly where it needs to go and again all the flight control surfaces deflected military power because the engines are black if you will on this one on the next time around you'll see him maneuver with afterburner and you'll see him get into this pitch induced oscillation that's the chase airplane by the way it's an f-16 that follows them around so same thing getting set up to land the camera goes out of focus here for a second comes back in again just notice everything that's happening on the back end of this airplane to keep that pitch rate where the pilot has commanded it to two things will happen here he selects afterburner and he raises the gear that changes the flight control laws and the gains were not set correctly there's the afterburner and now you see where he's out of phase with the airplane and he's doing everything to keep the airplane from hitting the ground and can't can't avoid it he's okay but the airplane was fairly well scraped up you can imagine so it's just a danger right that the digital flight controls allow a lot of flexibility and creativity there used to be a term it's only software you know we can figure it out not true when you're dealing with you know vehicles like this where small changes of software code can have dramatic implications on the ability of the airplane so takes amazing amount of demo yep you can go and do rapid demo and with that we can go questions because I'm a little bit over no that's fine okay so we can play this full speed or full full screen if you will you want to take questions while it's running out yeah so this is from another good buddy of mine guy named Ezekiel aqui who was the Raptor demo pilot outstanding guy but this is the Raptor demo if you ever seen it so we'll take some questions while this is gone go ahead yeah greater than one to one so the airplane about 63 64,000 pounds normally a sterling takeoff the thrust coming out the back is 70,000 pounds so on a nice cold day like if you're close enough to sea level you will actually go faster than the speed of sound while you're climbing up which is cool let's try it oh yeah try to repeat the question if you can oh sorry because he's not miked so the question was well one the question was is thrust to weight ratio its greater than one to one a little bit greater than one to one on takeoff by the way watch this we know over here real quick so that's the thrust-vectoring kind of kicking in to really get the airplane so initially that's the flight control surfaces and then as things slow down the thrust vectoring kicks in to basically turn the airplane into a flat plate second question was about the thrust vectoring on takeoff so it'll put in a little bit up not much just a little bit up just to help the nose rotate but adjust just a tad this is that high angle of attack kind of a new very few will keep going it's all good questions yeah very much so in fact we've kind of achieved that spot now where the pilot very much is limiting the performance of the airplane itself because the airplane could do so much more what you so this is what's called a fifth-generation fighter first generation was like an old Korean War like f-86 kind of airplane and then successively through the generations you arrive at this fifth generation which to me is the pinnacle of what you could get with a human and an airplane together six generation is gonna involve teaming this airplane with unmanned airplanes and the unmanned airplanes are gonna have a lot more capability from a maneuvering standpoint because they don't have the limitation of the pilot and all the life-support systems that come with it and everything else so all that weight you would normally devote to that you can get away with putting other stuff in there when I was telling you fly is about the same speed I was like Cessna I mean this is those types of maneuvers there where you can get away with that again watch the flight control surfaces in the back and what's going on later on they'll do a pass where he'll open up the doors and you can see the main weapon Bay which is underneath the airplane belly and then you'll see the side weapon bay doors so you can kind of see kind of where all the weapons are carried inside the airplane again a huge center of gravity challenge incidentally so here's that maneuver in air so you can see the doors open one thing I didn't really tell you about is so in that situation because you know missiles weigh a couple hundred pounds of piece or so some of the bombs are about a thousand pounds of piece when you lose all that weight immediately it's literally like dropping a car off the front end of the airplane the way that it fixes that center of gravity issue is by changing fuel inside the airplane sowhat's sloshes feel forward or back to keep the center of gravity again completely pilot there's no fuel control panel where I go well move this and click this and whatever it does it all completely automatically good you can use so all of the fuel tanks are instrumented so you know the status of fuel in terms of where things are set up it you tell it what actually it has the ability to know what's on the airplane so when you load a missile it goes oh it's this type of missile and it goes it weighs this much and it knows the mass properties of it and so it sets it up from there so it actually identifies that all by itself so like in a in a Cirrus you have to go you have to actually pull up a screen in the Cirrus and go my passenger weighs this and I've got this baggage onboard and then it gives you the picture of where the center of gravity is this thing because it's all digital the missile has a little connector rod that connects in and it says behold I'm a missile oh the pilot wait doesn't matter because they they they SPECT it well it matters but for a different reason it matters for the ejection seat predominantly because the ejection seat you know I think it's like 135 pounds is the light it's something like that hundred and fifteen hundred thirty-five to like 220 or something it's something around that spot so to be able to be within the safe envelope of the ejection seat that's where the weight of the pilot matters but they expect the center of gravity such that so long as really anyone can sit up front and you're not gonna throw off the CG of the airplane even though you're way far forward of the of the CG and there's a moment arm there but between everything else in the cockpit I mean that ejection seat is ridiculously heavy and all the avionics that sit up front the radars up front I mean all these things that sit up there have far more of a contribution to the center of gravity than you do unless you're like Shaq or something like that but good in this airplane not yet that's coming along soon some of the older airplanes believe it or not have that like the f-15 that I flew you had a special helmet that had all of the information displayed on the visor itself so in addition to that hands-on throttle and stick so I don't have to my hands off of anything to touch anything in the cockpit I also don't have to look in the cockpit to see altitude airspeed heading it's all displayed to me up front this airplane eventually will get that it didn't make the this is a programmatic discussion now right though they only had so many dollars to spend and they said this airplane is so awesome that it shouldn't need a helmet-mounted display system because it should be able to see all the bad guys from far enough away and not be a problem we fielded the airplane that way and every pilot you so the first batch of pilots they all transitioned from airplanes that had that helmet mounted system and they came to this airplane where it didn't have it and they were pissed they're like weak we got to have that back right so that's kind of where a lot of the efforts now are going to modernize the airplane a bit what else good questions good yeah the great debate of the fighter community right now and you're really touching on something really really deep the best answer so far is that the greatest I mean we talked a lot about the hardware and the systems on board the airplane really the greatest piece of capability on the airplane is the mind of the person flying up front if it's a very dynamic and changing environment to be able to tell a machine to be able to incorporate all those inputs and make the right decisions based on that kind of hard to do right now I'm not saying we're not going to get there just right now it's it's difficult where where we use unmanned systems a lot now is like in surveillance missions where you can just launch the thing and it's got a pre-programmed navigation then it knows what it needs to do and it can set things up those are somewhat bounded problems probably the best way to describe it where you could use an unmanned system for that work it's difficult is in combat situation it's it's extremely dynamic its its battle royale WWF mosh pit any possible chaotic situation you can put that's kind of what it looks like and so having a human mind attached in that environment to be able to adapt and do what the mind does better than a machine does at least right now that's the main argument to keep humans in the system for now right yeah through these things not mind me it is yeah the question is is that if you operate these things remotely so even if you had so you know classic example we'll use Sully Sullenberger all right as like because we talked about Sully in the previous one you take off out of LaGuardia you lose both engines if you could have a remote pilot sitting somewhere else that could take over and decide land on the Hudson because a machine most likely wouldn't have made that choice is there a time lag issue the answer is 100% yes there is a time lag issue between getting that information displayed down make the input that input goes back up and comes back over a thing we've done at test pilot school is remember we showed earlier that flight path marker where as a pilot you put the flight path marker and that's exactly where your airplanes gonna go if there's a time lag that will actually mess you up because there's some second or two delay between what you're seeing and what the airplane is actually going at test pilot school they actually built a flight test or flight path marker that accounts for that time delay if it knows that time the label actually account for it so you could fly the airplane remotely even with the time lag and still be able to do very high gain tasks like land the airplane for instance where things are changing very rapidly so it's a new science not fully fleshed out here but the proof of concept has been demonstrated to control an airplane remotely even with the time lag who really cares about that right now are the airlines because to be very frank the pilots tend to be a pain in the butt for an airline company and if you can remove the pilots and just have a remote operated system or even though that autonomous system to the from a business standpoint the company really likes that from an aviation standpoint rigors all types of discussions in a lot of other issues but that's one question good let me jump let me jump in for a minute with that I think actually to me one of the Holy Grails of GA safety would be to have a human co-pilot perhaps you know on the ground so if you had that kind of telemetry that you have in a in a drone you know humans somewhere else could say you know you're running a little short on fuel or you forgot to change tanks all the things that human copilot could do right in the cockpit you know most of that safety running checklist could be probably enhanced remotely so that would be a great add to a session or Piper even and you see a little bit now in some of the more advanced airplanes like we talked a little bit about if I have an engine problem in the Raptor I literally do nothing I just sit there and stare at the clouds and go wow what a lovely day and look the computer fixes it for me right there are other scenarios where the jet will tell me hey you've got a generator problem and then immediately pull up the checklist for the generator failure to allow me to fix it so you see some basic automation right now kind of already in play a couple other questions I know we're running short cut yeah so we have two terms once called beyond visual range which means I can't see the other guy with my eyes but my sensors can see him and if I'm shooting missiles long-distance like that I don't lose any seat-of-the-pants by being remotely it's like a video game like literally it's exactly like a video game if it's a maneuvering environment where I see the guy we're in a dogfight then yeah you lose a lot right in terms of seat-of-the-pants eyeball just things that are hard to to automate so it's half and half right in a drone scenario I mean what would a drone dogfight I don't know it's a good question I'm not really sure God but then I have to have some way to represent the physical environment that the drone is seeing I got to be able to represent that to the guy on the simulator on the ground I got to be able to kind of relay that real-time it matters so who plays sports right guys you know any I mean whenever you're playing sports you got an opponent you get if you play a lot like if it's a racquetball or football or something like that you get very good at looking at your opponent and being able to see micro movements before the actual big movement happens so that you know oh they're about to swing this way or they're gonna throw this way so you can read your opponent and make a decision about what's about to happen a second or two from now in a fighter jet the exact same thing if I'm fighting a guy and I see a control surface deflection even before the airplane is gone I know person's going this way I can position myself to be there before they arrive I would need some way to represent that if I'm in a simulator on the ground and it would have to be kind of transparent to the guy in the simulator what that feels like yeah lots of good questions it's good class let me ask actually where's who's here from the Flying Club from Sebastian yeah actually I wonder if lies can you stay another 10-15 minutes absolutely why don't we have Sebastian jump in give his Flying Club spiel and then both of them will be upfront for questions right afterwards thank you guys [Applause]
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Channel: Philip Greenspun
Views: 1,455,153
Rating: 4.8889809 out of 5
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Id: 22u4qxm1YjY
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Length: 66min 28sec (3988 seconds)
Published: Mon Mar 04 2019
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