Complicated flight stuff...

[Chronocidal]

Dunno if this is quite the right forum for this, but since all the other CG stuff is here, figured I'd try here first.

Apart from a working cockpit, my YF-19 model for Microsoft's flight sims is done.. I'm attempting to put it in Combat Sim 3, but several things have got me stuck. CFS3 isn't as simple as some games, where you just put a model in the game, specify it's maneuverability rating, speed, and hull strength, and it works. This thing is asking for everything from wing load coefficients and engine rpm ratings, to the actual wing area and fuel load. Suffice to say it's complex, and would be much easier if I were doing a real plane, with real specs. Is there any website or reference that actually lists such statistics? My guess would be the Macross Design Works book, but I was under the impression that that was mostly artwork. I've got stats for the engine thrust, dimensions, top speeds, max/min takeoff weight, and service ceiling, but that's about it. In the end, I may just end up making stuff up, and hoping that it works. :S

Also, does anyone have any info on the actual workings of the YF-19's various control surfaces? Mainly I'm wondering about the wings. The rudders are easy enough to pick out, as are the workings of the canards in the front (just make the whole canard rotate)... but what kinds of control surfaces do the wings use? I'm guessing leading edge slats, from the "NO STEP" decals on the kit there. But the ailerons/flaps/elevons have got me stumped. How are they linked together? From the artwork I've seen, it looks like each of the four sections of the wing control surfaces can move independently...but should they? And does the plane have flaps, or some sort of elevon system?

[Macross_Fanboy]

For specs you can try RPG sites with information the VF-19 and the YF-19.

[Aztek]

You might try posting in the movies and tv section with a link here. There's been alot of cats kicking around the type of information you are looking for over there. David Hingten is one of the bigger aviation buffs around the forums. He may be able to come up with really good guesstimates of the info you need with our canon references for the physical characteristics of the -19. I'm getting ready to get FS2004, I'd love to see the -19 when it's ready ...

Edited January 10, 2004 by Aztek

[Chronocidal]

Well, there is an in-game shot of it in the CG thread, but it's a rough, untextured model, and has no cockpit at all, and it's been using the stats from an Me-262 Fortunately, I found that I can get a good estimate of the wing area, etc in my modeling program. It'll tell you the surface area of something, or the volume, or whatever, and I can use that to find the various stats of the wings. I did use the RPG stats for it, and I've got most of them written down.. what I don't have, I'm filling in by estimation from modern aircraft of somewhat similar type, fuel stats from F-15, etc...The real trick will be to see if these stats actually result in a plane that will fly.

[Lestat]

Talk to nanashi. If it's available information, he has it.

[David Hingtgen]

YF-19's my fave valk, here's what I think (based on the animaton):

Nothing on the leading edge. Certainly not slats. If you've gotta have something, give it the "current standard" like an F-16/22--a hinged leading edge. One big huge flap that is the entire front of the wing.

Trailing edge: outboard flaperon, inboard flaps. (That means the inboard section only moves when you put the flaps down--it's a flap, nothing more. But the outboard section normally acts like an aileron, but when you ask for flaps down, it'll go down as well---but if you want to roll with the flaps down, it'll still move, just not as much as normal--it'll try to still act as a flap (staying down) but will move a little) Basically, if you ask for "flaps 35", a flaperon will only go down to like 20, while the "real" flaps go to 35. This way, it's still acting like a flap, but if you need to roll, it'll go like 15 degrees either way--down to 35, or up to 5---it'll still move, but it'll have a "new" neutral.

The thing is--Hasegawa's kit doesn't agree with the animation. The kit gives 3, possibly 4 different control surfaces on the trailing edge. Maybe 2 up front. Are they "really" there, or just there because Hasegawa LOVES to add in panel lines and no-step markings? (And didn't want a nigh-featureless wing like an F-15) 4 trailing-edge controls on a fighter is unheard of. Only the most complex of airliner wings have something like that. (727, 747, 767, DC-10) If you want 3 or 4 control surfaces on the trailing edge, you'll have to come up with them yourself. Kind of depends what you consider canon. If you want, I will try to figure out a 4-control surface.

::edit:: Looking closer, I think it may be 3 on the trailing edge, with the inboard-most one just being a little mini-flap, like F-14's have. Only functional when wing is fully un-swept, and will move to match the main flap just outboard of it. Otherwise, it stays in "neutral" whenever the wing is at all swept.

Wing loading: YF-19's (in fact, all valks) don't weight as much as they should. It's like saying you've got a new SUV that weighs 2,500lbs. Unlikely. Maybe if it was made of lithium...

But, since you're going for a flight sim, and you want it to "behave" right, Try from 80 to 130 lbs per square foot. 80 would make it like an F-16 (if you want the thing agile as heck), 130 would be like an F-14 (more appropriate, since the YF-19's pretty bulky compared to it's wings). But with the YF-19 being very light for its size, plus its small wings, it'd probably come out to be pretty normal by today's stnadards anyway.

::edit again:: So you can get an estimate of the wing area? Well then plane weight divided by wing area is your wing loading. (Of course, whether it wants full or empty weight is the question--most fighters usually list "combat" wing loadings--a decent fuel load, and a decent missile load--not full, not empty)

Could you specify the engine stats it wants? Is it asking for like N1, EPR, EGT, or what exactly? Anything not mentioned, I could make up a believable stat.

Here, you might be interested in this pic:

Edited January 10, 2004 by David Hingtgen

[David Hingtgen]

You'd probably be more interested if I remembered to attach it:

[mk16]

Oh man I've been wanting to make a valk for Fs for so long. But without having a good knowledgeable level of airplane engineering, i wouldn't have been satisfied with my end result. Its a great thing someone is tackling this. Man I wish you the best of luck.

[Mr March]

David Hig, what book is that picture from? Does it contain many more cross section drawings of Macross Mecha? What other artwork does it have?

[David Hingtgen]

I actually have no idea. It's been on my hard drive for years. Just a lone cutaway. No others that I know of. I'm pretty sure it was an attachment from this forum from long ago.

[Aztek]

David,

I know of only a couple fwd swept wing aircraft. Are there any references you know of that the -19 could have it's flight model designed after? I think that an old valk made for FS2000 was modeled after the -14 flight model. Maybe with some references for a similar aircraft he can get a decent model working. If I remember correctly, the only fwd swept aircraft I've seen was single engine. This may impact it's performance when rolling as opposed to a twin engine aircraft.

[David Hingtgen]

As it is, the Su-47 is the closest thing to a YF-19. The X-29 is FSW, but shares no other useful similarities. Remember, FSW doesn't actually do that much at all. Better roll stability at extremely high AOA, and that's about it. (Man I wish the old MW forums were back online, with my 4-page mini-dissertation about what FSW really means for the YF-19) I can't remember half of what I wrote...

The thing is, the Su-47 basically has leading-edge ailerons. I haven't tried to figure out how they work yet.

FSW planes don't fly differently than regular sweep. Just be sure they've got really strong wings, and powerful engines, if you plane on going supersonic.

Su-47 wouldn't be a bad thing to copy, just I seriously doubt there's much info on it.

Overall, the YF-19 has been demonstated to have insane pitch abilities above all else (and darn good roll) (whereas the YF-21 seems to be better at rolling than pitch). Combined with high AOA stability, you might actually want to look at the F-18 as the closest "normal" plane for the YF-19 to fly like. (only much, much faster). YF-21 would be more like an F-16.

[Chronocidal]

Heheh.. actually, I was able to find quite a bit of info, at least as far as weight, wing area, etc. goes... it's got a much bigger wing than the YF-19, though.

I've got to apologize for something, I misread the characteristics the program asks for.. it's not really wingloading. What I thought was weight loading is really just a way of determining how weapon payloads, fuel, etc will affect the aerodynamic model of the aircraft. The system for determining flight characteristics is brutally precise for a game, I must say.

As far as the control scheme goes, I think I have an answer that works, but here's the problem: They designed this as a WWII sim from the ground up. What does this mean? Well, mainly, no fancy hydraulic control systems, no high performance flight computers, and no way to make a plane fly well above about 600mph. Microsoft must not have taken creativity into account when they allowed people to put more aircraft in the game. The technology to make newer planes flyable just isn't there. As a rule, any aircraft that goes above about 550mph starts shaking and wobbling like nuts. On top of this, at that speed, the control surfaces become pretty useless from all the air buffeting. Also, in this program, there is no such thing as a flaperon, let alone leading edge controls, thrust vectoring, or any number of modern advances in flight control that something like the YF-19 depends on. I can make the plane as maneuverable as possible, but it's going to be very limited as far as engine performance. Also, the closest I can get to flaperons is to use elevons all along the back edge of the wing.

Thanks for all the input, I may still be able to get a decent plane out of this. There aren't many big differences between this game and the other flight sims, so I can probably get everything working in FS2002. I'm going to check out how I can export it to that program, and see how it handles.

[Mr March]

Damn. Thanks anyway Dave.

[Valkyrie Nut]

the model looks very good so far. I cant wait to see it done. Question: Will the thrust vectorers (feet) move accordingly to the axis?

[Chronocidal]

Hehe.. that's a big question I'm trying to find the answer to myself... it doesn't look like they will be able to. There's just too much mobility in those feet for the game to accurately simulate all the ways they move. They are linked to nearly every axis of control (roll, pitch and yaw) as well as actually functioning as a focusing mechanism for the engine... I'd probably be limited to one axis of movement, and even then, I have no idea how to make an engine's thrust change direction with control inputs.. I know it's possible, from all the harrier mods out there, but I'm at a loss for finding any decent guide for making that stuff work. Heck, I'm at a loss as to how to even make the plane fly decently. The game scales thrust incorrectly, and anything over 25000 lbs of thrust per engine results in an out of control straight up acceleration. Right now, the plane is bouncing around on the ground like a balloon before takeoff, something to do with the landing gear mechanisms. I've re-started from scratch MANY times over now.

I have got a few things working finally though. I went ahead and added leading edge slats like you see on some older fighters.. I'll probably replace them later with simple flaps, but the sliding animation just looks so cool. I've also experimented with the feet, trying to make them close up, and slide into the legs when the engines shut down, like they did in Mac+, but I don't know the part name that will let them animate. I have got the compressor blades spinning in the engines, and the cockpit canopy is fully animated now though.

Now, to just get rid of that darn instability...

[Aztek]

Are you still using Combat FS or have you switched to FS2002?

[mk16]

Ooohh news of anykind of progress is good. If you need help with making the airplane behavior maibe the guys on avsim can help.

Edited January 13, 2004 by mk16

[Chronocidal]

I'm actually kind of doing both simultaneously. I've got the plane working pretty well in both, but in CFS3 the speed is limited to about 600 mph. Both games use the same type of aircraft aerodynamic configuration files, so I'm hoping that tuning it to work in one will transwer well to the other. I've been adjusting the various details of the plane, like flap drag and lift multipliers, and adjusting how it performs... it still has a nasty tendency to stall at high speeds though.. I dunno what causes it, but at high subsonic speeds, if you pull all the way back on the stick, the plane gives you a stall warning.. then, for some reason, the wing starts working in reverse, and as you let off the stick, the plane starts diving... it did it at a high enough altitude to survive once, and after pulling a complete loop, once I let off the stick, the plane did a complete outside loop on it's own... very odd, and I don't know how to fix it. It's almost as if the plane has too much inertia, and pulling up at high speeds only changes the AOA, and has no effect on the flight path of the plane. But that doesn't explain why the plane forcibly dives after pulling a tight loop. I'm beginning to understand why the YF-19 went through so many test pilots.

Aside from that, the plane is handling quite well. You just can't leave the throttle on full and expect to do any kind of aerobatics. Also, it's a good idea not to pull all the way back on the stick above about 700 knots. The low speed handling is good, and landings aren't too hard to accomplish. I've got the flaps-down landing speed down to between 100-150 knots right now. I've also managed to add a few nice effects, like nav lights, etc. Also, thanks to the air traffic control system in FS2002, and a tweaking of the default aircraft ID, the control tower now addresses you verbally as "Alpha One."

Odds are I'm going to completely rework the model later on, since I never textured it. It needs a cockpit still as well, so that'll take time. What I want to really do is somehow duplicate the full canopy hud setup seen in the movie, with the surround screens. There are tricks to the animation parameters for some things.. I may link the exhausts to the throttle animation so they open as the throttle increases.. I may even be able to make bottom screens in the cockpit change from opaque blank screens to transparent windows by linking the texture opacity change to one of the cockpit power switches. I don't really know everything that's possible yet.

After this one, I think I'll probably either do a VF-1 series, or a YF-21/VF-22.. but it won't be for a while yet. I've still got to make the cockpit, texture everything, get rid of the last few bugs, and make a few variations (maybe VF-19A textures ).

Edited January 13, 2004 by Chronocidal

[mk16]

hmm how can i express what im feeling right now. :drool:

[F-ZeroOne]

Chrono, what you're describing sounds a bit like "compressibility" - you'll have to forgive me, as I've only read about it and most of it went way pass my head, but I believe this is where the airflow passing over the wing begins to exceed the speed of sound and locks up the control surfaces.

However, I've only ever heard about aircraft experiencing this in a dive, not a climb ( it was a big problem for prop driven aircraft during W.W. II ).

I believe Chuck Yeager also encountered a similar problem when approaching the speed of sound in the Bell X-1 - perhaps the game is modelling the same effect...?

[Valkyrie Nut]

I can't wait to see this finished ^___^