Not Downloaded yet
Version 1.81b
Initial Release November 18, 2020
Last Updated March 03, 2021
File Size 144.22 KB
Downloads 21,148
This file has been scanned for viruses and is safe to download.
#Real-Life Exclusive

Asobo Cessna Citation Model 700 Longitude Performance and Flight Dynamics Modifications Project Version 1.81b
Featuring Optional OnAir Virtual Airline Compatible Installation Package

Please check out the chatter and follow the progress of this project on the offical MSFS 2020 Forum:
https://forums.flightsimulator.com/t/cessna-citation-longitude-flight-dynamics-modification-project

Version 1.81b Changes:

  • Should resolve the issue for those who have had problems with installation of 1.81 with the Longitude no longer showing up in the aircraft selection menu. There are no changes other than updating the layout.json file. If you have not experienced issues with this, there is no need to download and install this version. 

Version 1.81 Changes:

  •  Reverts flaps lift coefficient back to prior values in response to Asobo's March 02, 2021 hotfix correcting Asobo's UK update error. This update will restore proper take-off, approach, and landing speeds after the Asobo hotfix.


Version 1.80 Changes:

  • Significant changes to engine parameters to achieve improved, "on the numbers", climb performance at various aircraft weights. Aircraft should follow Cessna spec climb profiles (300 IAS to intercept Mach 0.8 - 457 to 460 KIAS for high speed climb, for example). The aircraft should be able to intercept M0.8 and hold this speed for a climb of approx. 23 minutes to FL430 at MTOW and 16 minutes to FL430 at a takeoff weight of 33k lbs. Climb profile used in Cessna's testing for high speed climb is 290 KIAS to 10k feet (unrestricted climb), 300 KIAS to intercept with M0.8 (at approx. FL300) and hold M0.8 to cruise altitude.   
  • Adjusted engine thrust output as a function of N1 to bring this much closer to real world published N1 / performance results. The range of N1 values needed to maintain specific airspeeds, in particular at cruise, is quite narrow. This update improves performance to replicate this more narrow band of N1 vs thrust performance. 
  • Adjusted PID values for autothrottle to improve speed capture and hold speeds in general and with narrower N1 / thrust banding. There will be more/faster throttle lever movements and adjustments, especially at lower altitudes and airspeeds. This is somewhat experimental at this time.   
  • Adjusted aircraft lift paramaters to bring aircraft closer to real world V-speeds.
  • Further adjustments to stall speed boundaries and aoa limits. However, achieving realistic stall performance at the manufacturer tested speeds has not been possible without disrupting other significant aspects of aicraft performance - the sim doesn't read all values in the lift coeffiecient aoa table entries which makes this effort somewhat limited.
  • Slightly increased elevator authority to increase pitch control, especially at lower speeds like during takeoff and approach. 
  • Corrected flaps lift coefficient after Asobo update from Feb. 16, 2021. 
  • Corrected missing altitude alert callouts in OnAir version.


Please see version notes in the included install_readme file for a list of all changes made since project inception and a list of open items / known issues.

Installation:

  • Download the .zip file and extract to desktop or other location of choice.
  • Please read and follow the installation instructions in the included Install_ReadmeV1.81.txt file carefully.


Installation Note:
To confirm correct installation, when in the livery selection menu for the Longitude in MSFS2020, the default Asobo Longitude livery will display the following in the variant area "FDE Fix V1.81" or "FDE Fix V1.81 OnAir" depending on the install version you choose. This will help you quickly identify whether installation of the package was successful and identify package version - this will only affect the default Asobo livery listing and not other liveries, however the performance modifications will be applied to all livery versions.


The Cessna Citation Model 700 Longitude Performance and Flight Dynamics Modifications Project:
After reading user comments on the forums regarding the Cessna Citation Longitude model from Asobo concerning major autopilot problems, inaccurate weights, fuel load, fuel consumption, handling, etc... and due to my own poor experience and frustration with Asobo's starting efforts, I started work on revising a wide variety of parameters in the configuration files borrowed from the Cessna CJ4 model to match the specifications for the Longitude. I modified the default layout.json file for the Longitude to bypass the encrypted configuration files and point to copied versions of non-encrypted files from the CJ4. These files have all been heavily modified and with a fair amount of guesswork I've been able to produce a working version of the Longitude that is more docile in handling and produces performance numbers that much more closely match the real-world specs. I'm not a Longitude pilot, so my modifications are based on comments on forum topics from those who fly the type, and generous contributions of real world C700 aircraft performance charts, flight manuals, and checklists from fellow flight-sim enthusiasts who also fly IRL for a living. Input from type-rated pilots with knowledge of the aircraft handling and envelope will always be greatly valued.

NOTE: My adjustments are generally focused on performance and handling. Any issues with the G5000 suite and avionics in general are not the subject of this modification. If Asobo chooses to decrypt the xml files associated with the type, a motivated person could presumably start modifying and improving the avionics suite much like has been done with the CJ4 and other un-encrypted aircraft.

I have modified a great many variables and parameters in the available configuration files. I would greatly appreciate feedback on handling, control sensitivies, or other performance related parameters from knowledgable sources so I can continue to improve and update these modifications. If I missed something or you find a performance "glitch" please let me know.

Contribution credit and acknowledgements can be found the Install_ReadmeVX.XX file included. 


Pretty empty over here.


Pretty empty over here.

  • Version 1.81b March 03, 2021

  • Version 1.81 March 02, 2021

    Reverts Flaps lift coefficient in the flight model to previous values to resolve Asobo Hotfix change to flaps lift coefficient to value prior to UK update.

  • Version 1.80 February 21, 2021

    -Significant changes to engine parameters to achieve improved, "on the numbers", climb performance at various aircraft weights. Aircraft should follow Cessna spec climb profiles (300 IAS to intercept Mach 0.8 - 457 to 460 KIAS for high speed climb, for example). The aircraft should be able to intercept M0.8 and hold this speed for a climb of approx. 23 minutes to FL430 at MTOW and 16 minutes to FL430 at a takeoff weight of 33k lbs. Climb profile used in Cessna's testing for high speed climb is 290 KIAS to 10k feet (unrestricted climb), 300 KIAS to intercept with M0.8 (at approx. FL300) and hold M0.8 to cruise altitude.

    -Adjusted engine thrust output as a function of N1 to bring this much closer to real world published N1 / performance results. The range of N1 values needed to maintain specific airspeeds, in particular at cruise, is quite narrow. This update improves performance to replicate this more narrow band of N1 vs thrust performance.

    -Adjusted PID values for autothrottle to improve speed capture and hold speeds in general and with narrower N1 / thrust banding. There will be more/faster throttle lever movements and adjustments, especially at lower altitudes and airspeeds. This is somewhat experimental at this time.

    -Adjusted aircraft lift paramaters to bring aircraft closer to real world V-speeds.

    -Further adjustments to stall speed boundaries and aoa limits. However, achieving realistic stall performance at the manufacturer tested speeds has not been possible without disrupting other significant aspects of aicraft performance - the sim doesn't read all values in the lift coeffiecient aoa table entries which makes this effort somewhat limited.

    -Slightly increased elevator authority to increase pitch control, especially at lower speeds like during takeoff and approach.

    -Corrected flaps lift coefficient after Asobo update from Feb. 16, 2021.

    -Corrected missing altitude alert callouts in OnAir version.

  • Version 1.75 February 10, 2021

    Fix is incorporated for problem with reverser sound coming on during flight while at high speed idle. Was achieved by adjusting minimum idle N1 value to 28%, without any knock-on effects on aircraft performance.
    Fixed low N1 power band (between 2x% and 60%) to provide more thrust control at low N1 values resulting in improvements to taxi and pattern power settings.
    Fixed issue with engine spoolup time being too quick and resulting in oscillations around target N1 value.
    Added altitude alert callouts from 500 feet to 50 feet when descending on approaches. 500, 400, 300, 200, 100, and 50 are modeled. Additional callouts may be possible by using third party mods available and may be included in subsequent release.
    Adjusted high angle of attack lift coefficients to produce more reasonable stall performance. There are some interesting and inconsistent Asobo modeling behaviors in this part of the modeled flight envelope and as such I will consider this modification to be experimental at this time. Further investigation and testing may yield further improvements and refinements. With this version, the aircraft aoa needle will enter the red zone and the stall aural alert will sound about 10 knots before the target stall speed for a given flaps and weight configuration is reached (prior versions would sound the stall alert as soon as the aoa arrow entered the red and at the target stall speed). As speed bleeds off and speed hits the target stall speed for the given configuration the aoa needle will be at the limit of the aoa meter. At stall speed, the aircraft will either continue to fly into the stall as airspeed decays or it may abruptly drop the nose or wing over (preferred behavior). In testing I have seen both behaviors with no explanation for why one or the other occurs, and I will continue to explore further to determine why the inconsistency occurs and attempt to finalize a build with a correct stall speed and behavior set.



Title Subject Last Updated Answers
Longitude Flight Dynamics Modifications Project
Support
December 06, 2020
image
image
image
image
help
Support
December 06, 2020
image
image
589 Comments
  • image

    I've uploaded a new version of the 1.81 installation package that should hopefully resolve the disappearing Longitude mod problem.

  • image
    AnnaM
    March 03, 2021

    Thanks for this terrific mod, which has worked flawlessly right up to and including v1.80. With the latest v1.81 I get a CTD during loading, before I get to the menu screen. I've isolated the mod by having nothing else in my Community folder and get the CTD every time, until I remove the mod and restore the original layout.json.

  • image
    Dennis98BE
    March 03, 2021

    I can't get it installed for some reason. Each time according to the description I overwrite the layson file and then add the fdefix to the community folder. Every time the plane becomes invisble. I don't have MSFS installed in my LocalCache\Packages\ files but just on D/MSFS. Would that be an issue?

  • image
    dakfly0219 replied Author
    March 03, 2021
    I don’t know and would suggest posting your issue on the project forum on the official msfs forum and see if any of the smart folks over there could help.
    image
    zushi81 replied
    March 03, 2021
    i have the exact same problem, patch 1.81, i over-write layout.json add then put aircraft-longitudefdefix folder to the community folder. When i start game plane dont exist in game. if i delete your moded folder and restore the defualt plane its in the game. the 1.80 version was working fine
    image
    TypowyPapaj replied
    March 03, 2021
    I have the same problem
  • image
    ericosmith
    March 02, 2021

    I noted that the flaps fix was included in this file. Given the info on the hotfix, I removed this mod before the hotfix. I'm not sure whether I needed to do that or not or if the mod is going to be updated to remove the fix.

  • image
    dakfly0219 replied Author
    March 03, 2021
    Please see version 1.81 that addresses the issue with flaps lift coefficient.
  • image
    zushi81
    March 02, 2021

    I have installed FDE Fix V1.80 which is working very good , after some hours of flying i've noticed 2 things. One is, with that mod , every time i try to exit to desktop game stops responding and only way to close program is through task manager. And second after 2 completed flights , starting new is so laggy (fps drops).

  • image
    dakfly0219 replied Author
    March 03, 2021
    I have not experienced this and haven't seen reports of this problem previously. This instability is unlikely due to the mod package alone. It doesn't introduce new software / code or change the way the sim functions. My guess is you have another source of problems with your sim - possibly even the underlying Asobo Longitude code - or another addon or other software you are running in the background. good luck troubleshooting your issue.
  • image
    eriondfp
    March 01, 2021

    Is this compatible with the Steam version?

    - I replaced the layout.json in Official/Steam/asobo-aircraft-longitude with the one provided outside both downloaded folders
    - Then put one of the two folders (standard) into Community

    CTD when opening the game

  • image
    dakfly0219 replied Author
    March 01, 2021
    I don't run the Steam sourced software, but others have and I haven't had reports of issues until now. I don't know what's happened there with your install, but I don't have a ready solution. Perhaps try reinstalling the stock Longitude from inside the sim content manager and try installation again. If you are following the correct installation instructions and still getting a CTD, it sounds like a compatibility problem.
  • image
    Dillon
    March 01, 2021

    FYI, logo light is not longer working on the tail with the last update, ground handling seems a bit too sensitive now, and adjusting VS is more incremental now making it more cumbersome to adjust v speeds. It was better when adjustments were in the 100's. Great updates overall though!

  • image
    dakfly0219 replied Author
    March 01, 2021
    Haven’t touched logo light or ground handling parameters in several versions. I’ll take a look and see if I’m seeing the same.
    image
    dakfly0219 replied Author
    March 01, 2021
    I can still see the logo light. And ground handling still feels normal and not twitchy or overly sensitive. Are the rest of your aircraft lights working? Have you changed anything in your control settings that might be causing a change in control reponses?
    image
    Dillon replied
    March 01, 2021
    No, this looks like another UK update anomaly. I'm using the black tail livery, it was working before the UK update:

    https://flightsim.to/file/770/longitude-recolor-5-pack

    Concerning ground handling this may something brought on with the patch as well. Seeing as Asobo is going to release something this week nevermind. Let's see if they correct the default FDE in general which should help this. Did you do anything different with the tuning of VS? It's tuning in 50 increments versus 100 as before when I adjust the vertical speed.
    image
    dakfly0219 replied Author
    March 02, 2021
    It's more likely the logo light is functioning, but just not rendering on the color used in that repaint. Does it work for you on the base Longitude repaint?

    I have the latest patch as well and don't see a change in ground handling performance. Can you describe under what conditions you are seeing this problem?

    I changed the increments for VS in version 1.60 (so a few updates ago). This make it easier to control max rate climbs when using FLC and then having to switch over to VS mode when Mach hold won't work properly (Asobo bug). I haven't seen other complaints about this change.
    image
    Dillon replied
    March 02, 2021
    You are right! On other liveries with a white tail it's working. Don't know why it stopped working on my favorite paint. Although the tail is black the light made the lettering on the tail a subtle luminous blue, it looked cool. Oh well, it's not important. Concerning the ground handling, nevermind. I'll tweak my sensitivity settings. Thanks for all your hard work.
  • image
    Slider87
    March 01, 2021

    a me purtroppo non funziona... Evidentemente non so che cosa sbaglio.
    Ho seguito alla lettera tutte le istruzioni più volte ma niente.

    Scarico il pacchetto e mi escono fuori due cartelle. Non capisco il file Layout.json da quale delle due cartelle lo devo mettere. Spero qualcuno mi possa aiutare...

  • image
    dakfly0219 replied Author
    March 01, 2021
    Only install one of the two folders into the community folder. If you install both folders, it will not work. The Layout.json file to be used is at the top level of the .zip archive file (do not use any files from either of the included installation folders). Install the correct layout.json file into your Longitude official files folder, overwriting the default Longitude layout.json.
  • image
    Dannyhaya
    February 28, 2021

    I'm still enjoying your mod and the Cessna every day, the more i learn about this plane the more i enjoying it. So easy to fly en automated like hell! Thank you again!

  • image
    dakfly0219 replied Author
    March 01, 2021
    Thank you and you're welcome, glad you're enjoying and learning
  • image
    bigrabh80
    February 27, 2021

    Is nobody else having problems with the avionics switching off mid flight? Its happening to me almost every flight now! I might try the stock version to see if its still happening!

  • image
    dakfly0219 replied Author
    February 27, 2021
    I haven't. Assuming you are starting cold and dark, I would suggest you start by making sure that both generator switches and standby battery switch are switched on. This seems to be the problem for most who encounter this problem. Maybe someone else can provide a more detailed procedural flow for this during pre-flight and startup.
    image
    beldenmf replied
    February 27, 2021
    Hello,

    First off, great mod.

    I am experiencing a glitch where I cannot adjust the speed knob. Ive only gotten it to work once.

    If it helps, I tend to want to get in the air really quickly and use the Control- E method of starting most of the time. Using this method, I also encountered the same problem that bigrabh80 experienced with the avionics turning off about 20 minutes into the flight
    image
    dakfly0219 replied Author
    March 01, 2021
    As I mentioned before, make sure all generator switches are on, standby battery is armed, and the battery switches are on. Otherwise, you'll drain the batteries - hence the loss of avionics. Best to follow a good start procedure checklist to make sure you don't have these sorts of problems when starting cold and dark.
  • image
    Missiah
    February 26, 2021

    Wonderful, never want to fly without it again.

  • image
    Gboz
    February 26, 2021

    This mod improves over time.
    Very good work
    Thanks you !



© dakfly0219 - All rights reserved. Any reupload or redistribution of this file without the author's prior written consent is forbidden.
This Flight Simulator 2020 Mod was created by dakfly0219 and shared in Aircraft » All Aircraft for Microsoft Flight Simulator.

Dedicated Link Improve Report