F/A-18 C/D aircraft mod and textures (FSX/P3D)

[hd764jvgd843]

Upgrade v2.0.0 changelog:
- minor texture improvements throughout the pack
- specific station.laod.n values for each loadout adjusted
- adapted MOI values for each loadout, coupled MOI calculation corrected
- flaps lift and drag values improved, thanks to Pat's feedback
- empty weight cg moved to balance airplane for working pitch auto trim
- opted for working pirouette gauge instead of eye candy (ladder, covers, blocks)

Update v2.0.2 changelog:
- sideslip adjusted in accordance with changed empty weight CG
- flaps pitch scalar neutralized (FCS will compensate in real life)
- rudder control efficiency adjusted in conjunction with sideslip

Have fun,
Peter

[hd764jvgd843]

Update v2.0.3

Changelog:
- Sideslip slightly increased
- Pitch efficiency slightly decreased
- Texture USMC_VMFAT-101_200 added for NH C/D versions

Peter

[PhantomTweak]

Well, so far I've only looked (meaning flown, looks aren't all that big to me, although having the VMFAT-101 paints just rocks, IMO, but i am biased, oddly  )at the V2.0.0. It really does very very well, IMO.
Now, here we go with my annoying questions:)
I am only looking, at the moment, at the Training version, for testing consistency. no other reason.
- specific station.laod.n values for each loadout adjusted: Yes, but; why only 1 wing station each side, and why is the positioning for them -29, 0,0? Are the horizontal and vertical placements not critical? Are the other 2 averaged in? If so, why aren't the weights added to the existing wing station? IE: There are 2 wing stations on each side. They are placed approximately 1/3 and 2/3 of the wing's total span from the fuselage, and obviously slightly below the reference point. Are the outboards and inboards just averaged out to the ones shown, as far as positioning? Are their lateral and vertical positions so small as to be insignifigant, and only their longitudinal imortant? And what about weight? Shouldn't that 412, not the 206 for 1 MER/TER? I know, small piont, but I thought the placement of the weights might be important for the MOI calculations. Maybe not much, is why?

- flaps lift and drag values improved, thanks to Pat's feedback:  WOW!! Thanks for adding my changes in. Gives me a warm feeling to know I contributed, even in so small a way

- flaps pitch scalar neutralized (FCS will compensate in real life): Yes, but. It wasn't in the game. I was having to hold constant backpressure on the stick when the flaps came down to full. Is this proper? It's why I put in the pitch scalars I did. May well be just my system/joystick pair. On my system, the scalars I put in made my stick neutral in all flight regimes, with the pitch autotrim on.

- Texture USMC_VMFAT-101_200 added for NH C/D versions: Thank you! I appreciate it, even if no one else says anything about it

Until I can gather enough test time, that's all I have. So far. I'm sure there will be more as I go, as usual. Thanks for working so hard on this airplane. I sure appreciate the effort you are putting into this, as well as everyone else that is contributing!

Jimi, good to hear you're coming home. A cruise might be exciting, but they can wear a little thin after a time, I know. Enjoy the return!

Fair skies and 15 knots down the angle to alll!
Pat☺

[hd764jvgd843]

Thanks for the feedback, Pat. Much appreciated.

- Concerning the station.load.n values, in the calculations table all four pylons are accounted for but it seems I did not transfer it properly to the aircraft.cfg and forgot to enter lat. and vert. values, too. I will try to fix it ASAP.
As for the pylon weight, I took 200 lbs as an approximation because otherwise calculations would exceed the external stores max. limit of 15,000 lbs for the GBU version. I somehow assumed pylons need to be accounted for too, but now I am not so sure. Do you think I should change it to 412 lbs (pylon with ejecor rack)?
I found no value for the legacy hornet here so I took the (FA-18E) SUU-78 and SUU-80, each slightly below 200 lbs, as a reference here, with ejector racks included.

- Concerning the calculated MOIs for each loadout, all weights are accounted for, so if I understand it correctly no additional station loads need to be added at all. But the plane's weight (not MOIs) felt too light, so I decided to add the station loads again. Concerning this being an issue or no issue, I posted a thread on LM P3D forum, but I go no answer so far. I will try bugging them again to sort out how weight and MOIs should be done correctly.

- In the prior version, I had not been able to properly balanced the pitch auto trim, so your flaps pitch scalar were needed to compensate. I took a different approach this time and have moved the CG more to the front again, currently -29.6, in conjunction with wing aerodynamic center set to zero. I than tweaked the CG so long until I found the sweet spot for pitch auto trim.

- From time to time I need a change of scenery and than it is texture time. Glad to hear you like the USMC VMFAT-101_200, too. Currently I just started working on the NASA_X53_AAW texture and hope to release it next week.

I hope this explains a bit the hows and whys.
Peter

[PhantomTweak]

Glad to hear you like the USMC VMFAT-101_200, too.

Well, considering I was stationed with 101 in Yuma for almost 8 years, yeah, it's kinda neat to see the liveries live again on a new bird. When I was there, it was the F-4N, now the FA-18C/D's. Also, in my day, they were the F-4 training squadron for both Pilots and RIOs. We often got new RIO's in the shop, learning the fine points of the Aero-1A, then the AWG-10A/B/C, as time progressed through the different versions.
What we, and Corrosion Control Shop both really hated was when we got an LRU-11 in from the squadron a new RIO had used for a barf-bag. YECH!! And naturally, we got a few cards in it used as ash-trays, too. I will neither confirm nor deny rumors of finding roaches in it, and I don't mean cock-roaches!

Thank you very much for answering my questions, I appreciate it. It helps me understand where we're going, as we go (notice I now use "we", like I'm a big part of this LOL!)
As for the pylon weights, I was going by the latest MER/TER version weights, and what they used in the days of the C models are probably, in fact, lighter. I couldn't find a lot of data on the older ones, but I can keep looking, should you desire. As to exceeding the max stores load, I know that the ejector racks had to be accounted for someplace. I'll look at the NATOPS to see if they count as Stores, or weight of the wing (part and parcel of the plane) or what. I DID take a shot at the lat/vert positions, I can post them in here if you want. I assumed that they were about 1/3 and 2/3 of the way from the body to the wingtip, using the CG+ 1/2 fuselage width at the wingroot, and the wingtip lights for references. You would be amazed at how handy adding a simple steady light to find positions can be. At least for making the visual model postions match the positions in the aircraft.cfg for the different Station_Load.n points. Good for gear positions, too, tail hooks, engines, etc.
Reminds me, I did use that method to fine tune the engine positions in the [General Engine] section. Again, small detail, but the Devil's in the details, they say.

- In the prior version, I had not been able to properly balanced the pitch auto trim, so your flaps pitch scalar were needed to compensate. I understand now! Wasn't complaining, I was just curious as tot he why and wherefore's

Thanks again for the answers. Appreciate them I'll keep playing with the bits I know, now I understand what's going on, for a change. Hehe.
Pat☺

[hd764jvgd843]

You would be amazed at how handy adding a simple steady light to find positions can be. At least for making the visual model postions match the positions in the aircraft.cfg for the different Station_Load.n points. Good for gear positions, too, tail hooks, engines, etc.
Reminds me, I did use that method to fine tune the engine positions in the [General Engine] section. Again, small detail, but the Devil's in the details, they say.

One word of advice. I used this method myself a the beginning of my modding until I noticed that different models may have different visual flaws and do not always represent desired technical specifications. Example: FSXBA Hornet is lacking the correct negative wing dihedral (anhedral) in comparison to FSX or CS models, but on the other hand it has correct flaps animations etc. and is much more detailed in many other aspects. Jamal did a very good job with this 3D model. Unfortunately, the uncompiled model files were lost somehow, as I have been told, so improvements in this area will be out of reach, unless someone is willing to basically start from scratch again.

In order to get correct coordinates for the legacy hornet I started with technical drawings I could find and overlayed these with the respective absolute coordinates I knew to be correct (e.g. overall width, lenght, height). I then fitted transparent excel graphs (top, side and front view) with the correct coordinates to overlay with the technical drawings (unchanged aspect ratio) and derived all other needed coordinates from visual representation. I even found that the technical drawings, that I could find would deviate in some small details here and there. This method proved to be surprisingly accurate, when I later found some weapon station coordinates in NATOPS, deviations were well within the 3% range.

Peter

[PhantomTweak]

Thanks again, Peter, as always, your answers really help a lot.
As I understand it, the version in the JPEGs you posted is the FSXBA (or NH) Hornet? If so, then I worked on getting the station_load.n positions set, all 3 axes, for the triple ejector racks out on the wings, and the AIM-9's out on the wingtips, as well as their weights. According to the metrics you provided in the pics. I also verified my engine positions in the [General_Engine] section. I can post these if you want.
On that subject, according to the ESP SDK I use, the posional settings indicate the actual position of the thrust exiting the aircraft. Like, for a Prop plane, it would be the position of the prop on the nose, or wings, whatever. To me, and this is just my take on this, the thrust actually departs the aircraft at the end of the nozzles, or turkey feathers. Due to their changeability, they actually create some thrust when they close down, accelerating the exhaust gasses to higher speed, thus increasing thrust.  So, rather than at the start of the AB section, wouldn't the end of the tailpipes be the correct spot? I'm just wondering. I can put the position anyplace, after all. Although the positional information is not present in the .air file, it's not required, as the aircraft.cfg overrides the .air file settings. I believe.
Again, a very small matter, just my OCD for detail kicking in.
Thanks again for taking the time, and having the patience, to answer all my questions.
Pat☺

[hd764jvgd843]

As I understand it, the version in the JPEGs you posted is the FSXBA (or NH) Hornet?

Neither one. These JPEGs are cuttings from technical drawings I found on the web and I use to derive the needed/unknown coordinates for various station points, with the help of the Excel framework I build. I do not use the visual models (FSX, CS, or FSXBA) to derive any coordinates from it. The only cases I check for consistency is when lights, AB/smoke effects, etc. are concerned, which do not have an impact on flight dynamics.
Last night I already did fix the station_load.n coordinates and finished the NASA_X53_AAW texture. I will post an update shortly.

I can post these if you want.

Yes please, do not hesitate to post your findings and suggested changes with some explanations of why and how you did it, and if possible the reference you are drawing your reasoning upon. Every suggestion and bit of information you are willing to share is useful and welcome and I will definitely have a look at it and take it into consideration.

Example: If I understand you correct, the SDK states that the positional settings of the engines should be where the thrust is actually exiting the aircraft (or turbine?). This is new to me, I always aimed at getting the center of the engine turbines here.
Concerning your reasoning where that point may be, I concur, the end of the tailpipes could be the point with the highest velocity of gas output. I will have to get accustomed to that train of thought.
ESP SDK is quite large, please tell where you did exactly find this useful bit of information.

Yes, you are correct, as far as I know aircraft.cfg entries override .air file entries.

Thanks again for your valuable feedback, Pat, much appreciated.

Peter

[hd764jvgd843]

Update v2.0.4 (cumulative)

Changelog:
- station_load.n values (lat/vert) adjusted, pylons added where missing
- engine position adjusted, thanks to input/suggestion from Pat
- new NH texture added NASA_X53_AAW
- NH texture USMC_VMFAT-101_200 included

Have fun!
Peter

[PhantomTweak]

Hiyas Peter!
Ok, I found the place where I got the whole engine thing. It wasn't from the SDK, for which I apologise. It was from a PDF file on how to set parameters for FS2004 (I am presuming, perhaps falsely, they are the same for FSX) named "How to Tweak the flight dynamics of FS2004 aircraft.pdf" in "howtweak.zip". I found it on FlightSim. The download page reads

Name: howtweak.zip Size: 47,722 Date: 09-12-2005 Downloads: 1,855
FS2004 How To Tweak Flight Dynamics. This pdf file is for people who want to learn, or learn more, about updating the flight dynamics of FS2004 aircraft. It won't tell you everything, but it will tell you some things the majority of flight simmers don't know about updating flight dynamics. By Bob Chicilo.

.
I am not sure about the policy in this forum about links to other sites, like FlightSim. If it's permitted, I will post it.
The portion I got the concept from reads, in part,

Something to know about engine locations: The position of the engine(s)
is the point from which the thrust of the prop(s) or thrust of the jet eminates from. So if
you have some idea where the datum point is you can have some idea whether the
engine(s) seem to be positioned correctly. If you think they are not accurately positioned, you can check their position(s) with the light.

.
 That's what I was working from. If the information was erroneous, I sincerely apologize. I just double checked the SDK, and in the section [GeneralEngineData], https://msdn.microsoft.com/en-us/library/cc526949.aspx#mozTocId136011, it reads:
 

Offset of the engine from the datum reference point. Each engine location specified increases the engine count (maximum of four engines allowed).

.
Obviously, this leaves a lot of wiggle room for interpretation, so if I was mistaken, please feel free to let me know. It's how I learn!

I will post the positions I developed below. I'll just make a Text file of the positions I got, utilizing your JPEGS and, I am ashamed to say, a ruler,  helD up to the screen for a straight-edge to read the coordinates on the edges of the picture. Sadly, I am horribly far behind on learning Excel. I am going to start though, I will tell you that. The last spreadsheet work I did was in '90, so I have a little catching up to do, I fear.
Anyway, below, please find the text file with the pylon positions and weights I came up with. Oh, I changed the weight of the centerline Station_load to take the weight of the tank (381lbs) ON the pylon also. It's not much, but you know me.
Hope all this is of a little help
Pat☺

[hd764jvgd843]

Thanks Pat, I was able to find the file quickly.

As far as I understand it, it means that the cp for an engine should be placed at the endpoint/exhaust of the turbine, in our case. I do not think that there will be any differences between fs9 and fsx concerning this general understanding.

Concerning the placement of links, I never ran into any problems on forums for placing external links to sources, references or pictures. In case you want to communicate not in public you can use the "MY MESSAGES" function on top of this forum. It works like an email for this forum.

In case you are interested, I am willing to share the current version of the framework I have developed in Excel 2010. You can contact me through the forum "MY MESSAGES" and I will send you the file or any other resources I have found you might be interested in concerning flight dynamics and the development/improvement of the legacy hornet. This is a general invitation to all parties on this forum who might be interested, and are willing to share their findings with each other, too.

Separating the centerline station pylon from the tank is a necessity because the CS version just adds/removes weight for the tank, so in order to be consistent throughout the versions I opted for a separation in this case. The weight and position of the external tanks are located after the internal fuel section in the aircraft.cfg.

There is really no need to use a ruler on your screen, I can send you all the pictures of the technical drawings I was able to dig up too, so you can make use of any picture editing program, measuring the pixels directly and translating these into feet, since we know the overall length, width and height of the bird. Some of these drawing might need a slight rotational correction in order to be exactly orthogonal so you do not screw up your measurements.

One thing that has been bugging me lately again is the visual derivation of the wing twist, the difference of incidence at wing root and wing tip. I get different readings for each technical drawing here, and I am not really sure which one might be closest to reality. Although I do not think it will have a big impact on flight behaviour I just like to get it right and be done with it.

Peter

[PhantomTweak]

The weight and position of the external tanks are located after the internal fuel section in the aircraft.cfg.

Ok, I see how you did that. You increased the weight of the included fuel by increasing the gallons to make up the difference in the added tank weight. I understand that. However (yeah, here I go again ) : Wouldn't that weight then disappear when the fuel is used? I am pretty sure the externals are used first, so it's as though, when the tank empties, the pilot drops it. A viable possibility, no question, and even used to be policy. Drop external tanks before engaging in ACM. But in today's money-conscious Navy, they only jettison external stores (to include tanks) if they loose an engine on catapult launches, or during approach, or if they have FCS problems. SO: I guess my question would be, is there any way we can make the weight of external tanks stay on the aircraft, like the pylons do? Can we add another station_load.n for just each tank? Does it even matter in the overall scheme of things? Should I just ignore the weight of the tank, as it's so small and centered as to be insignifigant?
I'm not arguing, I'm just trying to learn the most I can

so you can make use of any picture editing program, measuring the pixels directly and translating these into feet, since we know the overall length, width and height of the bird.

That would be great! I do that for panel gauges and switches, etc, already, so I am fairly familiar with the method. I'll send you my email, if you like, or send me a PM (My Messages in this forum), your choice. I prefer not to post my email publicly, for obvious reasons.

I get different readings for each technical drawing here, and I am not really sure which one might be closest to reality.

Can you take the various different values and average them to get at least a value that comes someplace close to a correct reading? Or is it possible to grab a still from a video or picture of the real aircraft in operation, say sitting still on the flightline, for example, no external stores, overlay the metrics in Excel, and use that? In flight, obviously, the wings constantly flex, but sitting still on the line or on the end of the runway, full fuel, I presume, they would be pretty still, and close to "correct" (accurate?). Just offering a suggestion

I sure do appreciate all your valuable time taken answering all my questions. It's the best way I've found to learn from the pro! I'll be around as much as I am able. I really wish I had more time to devote to this.
Pat☺

[hd764jvgd843]

The weight of the empty external tanks should be added as additional station_load.n entries, this is a good idea, Pat. Do you have any values for the legacy hornet ones. I haven't yet stumbled over them, at least I found that for the FA-18E: the empty weight for an 480 gallon external fuel tank is listed at 381 lbs. It is proabably close in relation to the legacy hornet one but that only has a capacity of 380/385 gallons. A first rough linear approximation would be 306 lbs. After some volume and surface calculations taken into consideration for a cylinder it should be closer to 326 lbs. I will add it as a first approximation with the next update.

In flight, obviously, the wings constantly flex, ...

Sorry Pat, I mean the wing incidence (at root/tip, and the respective wing twist) not the wing dihedral/anhedral that will change with the flex under load or during high g maneuvers. When you look at the technical drawings from the side view, you will notice that each of them will have slightly different angles.

Today I have reworked the engine tables for the legacy hornet from an FA-18E because I have not found anything that comes closer and was able to set the induced drag scalar back to 1.0 which gives the bird a more realistic drag and flight behaviour again. There are more table entries for different altitudes now, which should in general give a more realistic engine performance for the various altitude levels, too. I am still experimenting with it.

The next textures I am currently looking at and I will try to finish are the NASA_HARV and NASA_TestPlane ones. After these I will have to cut back on the amount of time spend with this project because honestly speaking this has become quite addictive and I have started neglecting my other duties.

Peter

[PhantomTweak]

 

Do you have any values for the legacy hornet ones.

Well, I am presuming you mean the C models?
According to the NATOPS I have for the A-D models, A1-F18AC-NFM-000, pg. I-4-12, they weigh: there are two possibilities, actually. There is a 315GAL tank, weighing in at 454lbs empty. And a 330 GAL at 429.

These are compared to the E/F model which has a 480 GAL, weighing in at 381lbs empty. Seems the older ones are high, but I believe the older tanks weighed more due to materials used in construction, perhaps.

These are the weights in the NATOPS manual, anyway. They may be adding in the single station, internal ejection machinery, perhaps, or maybe the C model had to use a single ejector pylon for the centerline, with the E/F having the internal ejector built in.

Sorry Pat, I mean the wing incidence (at root/tip, and the respective wing twist) not the wing dihedral/anhedral that will change with the flex under load or during high g maneuvers.

OH! Woops, sorry. I misunderstood. A common failing of mine
My idea remains, though, would averaging different sources readings for this be an acceptable solution? Just a thought .

Edit: Thank you very much for the data file. It will take me a bit to work through it, especially the math in the Flight Dynamics PDF file. It's been a LONG time since I did some of that math, although some is fairly easy. All depends on what one uses, I suppose. I worked up through Calculus in my Navy/MC schooling (Avi-C7), but that was in '82. I may take me a bit to get back into it, but I'm nothing if not stubborn, if not to mention relatively good at math (Although my appearance may seem to belie that). I will get it down (please note: I will never use the phrase "Down Pat" ).  Since PDF files are small when by themselves, I have one similar to the Flight Dynamics one I can will send you as an attachment. It's very much similar, as far as the mathmatics goes, and has to do with the sections 1502 through 1507 in the air file, and how to properly set them. It may be of use to you, as you mentioned you are going to be working that area now. PSB
Pat☺

[hd764jvgd843]

Update v2.0.5

Changelog:
- weight for empty external centerline tank added where appropriate
- engine tables reworked in conjunction with
- reset induced drag scalar to 1.0
- air file entry no. 1523, turbine variable inlet, corrected to 'false', which increases subsonic engine performance offsetting the additional induced drag caused by the reset scalar
- air file entry no. 1524, turbine afterburner thrust factor vs mach, adjusted to work in conjunction with changed engine tables
- new texture for NH version finished: NASA_TestPlane_852
- texture NASA_HARV_ANSER implemented, but still under construction

Note: Reworked engine tables and reset induced drag scalar give the bird a more realistic drag and flight behaviour. Additional engine table entries should also give a more realistic engine performance at various altitude levels.

Peter