Asobo Cessna Citation Longitude Flight Dynamics Modifications Project Version v1.21
Version 1.21 is an interim fix that corrects autopilot IAS hold limit and increases roll authority for autopilot.
Version 1.2 has been updated with the following improvements:
This is still a work in progress, but this update will address a primary concern about using liveries along with these improvements to the handling and performance of the Longitude
-Should now work with other Longitude liveries
-Additional refinements to handling
-Addressed issue with autorotation at takeoff trim setting
-Some refinements to engine performance and fuel burn
-Updated autopilot limits and braking power
-Corrected issue with electrical bus tie – now shows always on when engines are running
After reading user comments on the forums regarding the Cessna Citation Longitude model from Asobo concerning inaccurate weights, 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 for the Cessna CJ4 model to match the specifications for the Longitude. I modified the layout.json file 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. Not a Longitude pilot, so my modifications are done purely by feel and speculation and comments on forum from those claiming to fly the type. Input from type-rated pilots with knowledge of the aircraft handling and envelope would be greatly valued. 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, they could presumably start modifying and improving the avionics suite much like has been done with the cj4 and other un-encrypted aircraft.
My first effort achieved the following:
-Completedly eliminated porpoise and roll oscillations while using autopilot at all altitudes and airspeeds
-Corrected aicraft weights, fuel loads, payloads, etc…
-Increased number of payload stations to better approximate real-world
-Modified engine performance and fuel burn rates at cruise (burns b/w 1600 to 2000 pph)
-Significant reduction in the twitchy pitch, roll, and yaw sensitivities
-Better approximation of takeoff, approach, landing, and stall speeds (clean and dirty)
-Generally improved handling at all altitudes and airspeeds
-Improved ground handling
-Added a tail / logo light missing from Asobo’s original model.
I modified a great many variables and parameters in the 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.
If you’ve previously installed V1.1 or V1.0 some cleanup is needed before installation of V1.21:
1. In your \LocalCache\Packages\Official\OneStore\asobo-aircraft-longitude\SimObjects\Airplanes\Asobo_Longitude folder remove the following files if they exist:- aicraft.cfg- systems.cfg- engines.cfg- flight_model.cfg
2. Remove the entire Asobo_Longitude-DynamicsFixV1 Folder into your \LocalCache\Packages\Community folder if it exists
3. Go to the Clean Install instructions below
New / Update Install:
1. Recommend backing up all of your default Asobo Longitude files in the \Packages\Official\OneStore\asobo-aircraft-longitude.
2. Over-write the original “layout.json” file in the LocalCache\Packages\Official\OneStore\asobo-aircraft-longitude directory with the included new layout.json file I’ve provided.
3. Copy the “aircraft-longitudefdefix” Folder into your \LocalCache\Packages\Community folder. Overwrite prior version when prompted.
4. Go flying!
Special thanks to JeffreyCobra for assitance with the install package, BanjoApocalypse for insights into the Longitude performance envelope, Dihedral977 for useful a/c performance documentation. Thanks to the flightsim community for comments, encouragement, and feedback, and of course to Asobo for developing an overall great product.
These files are provided for free, as is, with no warranty expressed or implied. These files are to be used only by users of properly licensed versions of the software which these files are intended to enhance or modify. No support is provided for these files. By downloading and using these files you agree to waive any rights to remedy for any damage to your computer systems, software, or user files that may be caused by your use or misuse of these software files. If you modify and repost or publish these files in the public domain, please credit the original author.