Not AAU1: Cessna Citation Longitude Flight Dynamics Modification Project

Actually, that’s what Asobo is presenting. I was talking about the real aircraft. Take a closer look at the thrust levers and follow the arrows:

Now look in front of the levers:

It’s shown as “inop.” but there is a binding for it:

EDIT: It’s NOT inop. Take a look:

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Jeez the mapping is found under the Autopilot section…thanks for pointing that out !

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Hi,

I was just about to try this beauty with your mod. But even though Im following the readme instructions, it seems not working for me.

I can place the “aircraft-longitudeFDEfix” folder to my “community” folder. Its fine. But as soon as I overwrite the default.json file the aircraft dissapears in the menu and can not be chosen.

Any idea what am I doing wrong?

Thanks

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Yep, found it. Good catch. However functional it is, it took a lot of work to access the button in the SIM, I see your point. I’m using an X56 so it would be pretty easy to map my throttle similarly.

In other news, my e-brake button fell out:

(Looking at your pic, looks like yours did too)

This really is an outstanding aircraft, your work is just great on this. Makes having the sim worth every penny. Thank you! Asobo you should be talking to Dakfly0219, maybe put him on the payroll, this has made the sim fun, a great plane. Thanks all.

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Remove the newly installed mod files. Then try removing and reinstalling the default Longitude in the sim content manager (make sure you’ve backed up your original stock longitude files including the layout.json, just in case). Make sure your stock Longitude reappears. Then reinstall the mod. Also check you are indeed overwriting the layout.json file in the official Longitude package and not some other layout.json.

Darkfly, just being curious…if i may ask whats the roadmap for this great project?

Thanks in advance. :slight_smile:

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That’s a good question and one I’m sure would be of interest to a number of forum participants so I’ll put a bit of detail into this.

Here’s the long answer:
There are three key files that are part of the official encrypted Longitude product:
xml.fsarchive
model.fsarchive
cfg.fsarchive

These files describe the avionics and underlying code (xml.fsarchive), the visual model and animations (model.fsarchive) and the flight physics model and surface level systems, electric, and so on (cfg.fsarchive) and are called when the sim loads up by the layout.json file in the official files package. This is why it’s necessary to overwrite the official Longitude layout.json file; the sim will otherwise preferentially read the layout.json that appears in the default file structure and ignore any attempts to simply modify the a/c using a custom layout.json in the community folder.

The modification project involves completely bypassing the encrypted cfg.fsarchive to modify engines, aerodynamics, systems (very limited - xml and other code apparently over-rides the entries in this file), and the aircraft description and some visual effects, by using several .cfg files copied from the CJ4 (and one or two files in the Longitude official files package that I was able to directly modify and repackage). These files were then effectively reverse engineered to suit the Longitude. I was also gifted a whole lot of Cessna official documentation about the Longitude - this has made a world of difference in allowing the modification project to create a product that’s much closer to IRL performance than it ever would be otherwise. Any changes (and there are many) that you see in the .cfg files I’ve included in my mod package was uncovered by via trial and error and some educated guesswork based on past mod projects I’ve undertaken in FSX and Prepar3d (and prior versions). In other words, I have an incomplete “access” so to speak, to modifying the Longitude as I’ve no idea how to reverse engineer the two other files specific to this a/c - it would probably end up a complete mess. Additionally, a number of parameters / variables contained in the various .cfg files I’ve substituted for Longitude are not actually read by the sim (they do nothing or at least appear to do nothing), which further limits how much I can change the aircraft performance. Unlike other projects like the CJ4 or A320neo modification projects (where those a/c models are not encrypted) that have touched all manner of aircraft systems, avionics, and performance, I am far more limited in what I can affect - unless Asobo decrypts those archive files for the consumer. This issue affects all premium content a/c models - so this severely limits modding efforts for all but the base level product a/c models.

In short, in combination with the underlying problems with Asobo’s sim programming for things like turbine engines, aerodynamics, avionics, and the aforementioned limited files access I have to make changes, I’m running out of areas I can affect to bring more lifelike realism to the flight model and aircraft systems and avionics.

At this point, my future focus could consist of:
-provide some basic documentation on the a/c performance envelope and procedures (subject to the limits of the sim). I receive regular questions about performance limits (climb, cruise, Vspeeds, etc…) and procedures and it would probably be appreciated by fellow simmers to have this information, since Cessna has not made this available to the public at this time.
-if possible, develop a set of in-sim checklists to replace the very basic one currently in the sim.
-attempting to puzzle out outside of the envelope performance (low and high speed stalls). Presently, the variables / tables are present in the cfg files, but they haven’t been developed at all. As you may discover, the a/c will continue flying right into stalls without any apparent ill effect. In real life the aircraft will force recovery from stalls with a stick pusher. This isn’t modeled in the avionics, so I could attempt to model some out of control behavior when aoa limits are exceeded for the sim pilot who wants to tempt fate.
-further tinkering with engine performance to see if I can get a broader range of more realistic fuel consumption, temperatures, and output; I feel I’ve beaten this area to death, but there may be some further areas of experimentation especially as Asobo updates the sim to improve the turbine model (which they have - sort of, and which has actually changed how some of the variables work - frustrating some of my prior efforts in the process)
-make adjustments to elements of aircraft handling, aerodynamics, etc… if I receive further input from IRL Longitude pilots who test and report back on areas for further improvement.
-request/beg Asobo to adopt my changes into the official content so I don’t have to keep updating the mod package each time they update and overwrite the layout.json file. That and maybe to stop making “fixes” that continue to break the a/c handling and avionics. They appear to take a global approach to making changes to the underlying sim code that then have downstream effects on the various a/c models that then get published without much thorough testing.

I’m open to suggestions and areas for improvement, but at the moment they will be inherently limited to aerodynamics, engine performance, and the limited in-cockpit systems that can be controlled.

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Thanks for your great mod!

What about improving the default camera view, quickview left and quickview right?

For example theres one camera mod for the carenado mooney which is a life changer

I’ve been reluctant to modify cameras as these seem to be a matter of personal preference for many. Since it’s not a matter of how the a/c behaves IRL, I’ve left this alone. Perhaps this is an area for someone else to tinker with and come up with some optional camera definitions.

That might be interesting for you - had my first instant CTD today and it was (more or less) obvious what was the reason …
Made a flight plan with LNM while the sim was running, programmed the plan manually in the Longitudes flight planner (V1.51), closed LNM for performance reasons, had a smooth flight @FL350 with real weather, was curious about some city down there, opendend LNM: Bammm CTD.

I am looking forward to flying this plane after I am done doing my current TBM - WWT. I plan on using the CCL going the opposite direction this time. Hopefully the plane will cut my flight time around the world in half/one third. :slight_smile:

The biggest issue I see using the CCL in a WWT is the runway length issues compared to the short TBM takeoff/landing. At least ten runways around the world are short runways going into their respective countries small airports.

Other than practicing using speed brakes, flaps, throttle, etc., is there any other advice you can give me?

Just plow through the fence at the end of the runway? :slight_smile:

I will be sure to load the modification project into MSFS. Thanks, Dakfly0219!

With the mod i can walk (translate) past walls and appear outside the cockpit

Can this be fixed?

Any CTD is almost always due to a lack of resources on the computer. Whether that is a memory leak, not enough ram, two programs trying to access the same resource, etc. Based on your description, either there is a bug with LNM or you don’t have enough memory to run both programs simultaneously or (my guess) since it took a while before the CTD happened, you probably just ran out of memory. Whether that was simply lack of physical ram or a memory leak in FS 2020, I don’t know.

I have never had a CTD yet and I don’t usually run any other applications at the same time as the simulator. Also I have 32 gigs of RAM on my machine which seem to be enough. However I have not done any long-haul flights or flights over two hours long yet.

Thanks for your answer.

I’ve reported my CTD because that never happend before, even not when flying the WT-CJ4. And usually I’m looking something up with Firefox, which is a memory eater, during the flight. Or I’m listening to some online radio.

At that CTD nothing else was running in the background.

Maybe there is a bug with LNM because it seems to push my CPU to some limit I don’t see while using Navigraph Charts. Starting LNM always brings up the fans for 20-30 seconds and the CPU usage goes heavily through the roof.

But as I sad before, that never was a problem with other planes, just with the Longitude. I will avoid that combination for now.

I’ve had CTDs running the B787 and without any mods or other apps running since last Asobo update. Right in the middle of cruise - not messing with flight plans or otherwise interacting with the sw other than perhaps looking around - poof - crashed. I have 24G ram and a reasonably powerful computer. Two flights, two different departures and destinations. No 3rd party software running. Didn’t have this issue with 787 prior to last update. I’ve had frequent CTDs using longitude with WT G3000 latest version and after last Asobo update. Had to go back to stock avionics and no further issues since. I think the sim can be unstable in a variety of conditions and 3rd party sw does make it worse based on comments I’ve read in various topics.

You’re probably right, with every update something is broken and the mod devs have to refine their mod over and over again. So we have to be patient and thanks to people like you we already have a sim that is fun to use. I’m sure I won’t go back to X-Plane, though I loved it a lot and it had it’s advantages.

Keep up the good work and wait for my donation on flightsim.to.

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Are you using the last navigraph ?

I see this is a new “feature”. Or at least I didn’t notice this issue prior to that last update. Not sure that I can control this or not.

How’s anybody plane doing in strong crosswinds at cruising altitude? (Over 50kts)

Mine’s been acting Strange lately. It uses rudder + banking to compensate instead of pointing the nose in the wind. Ive made a 1h flight at about 25-35 degree roll.

If i recenter the rudder, ap disconnect.

Will try to do more test, but i got that 2-3 times

Wasnt doing that before latest update