[Mod] AirportCEOTweaks 2.4.0: Mod Loader Support!

As of 2.4.0 ACEO Tweaks Requires ACEO Mod Loader instead of UMF!

Steam Download Link

Manual Download Latest Stable Version (2.4.0)

If you’ve never done so; please read the post and especially the download instructions!
If you haven’t familiarized yourself with the (new) ACEO Mod loader, please do so - 2.4.0 only supports the new mod loader!

Required for New Aircraft: Tweaks Aircraft Pack

Current Tweaks Aircraft List

Strongly Recommended: Performance CEO

What’s New (2.4)?

  • Includes @humoresque 's emergency patch for dissabling certain planner elements if they cause crashes.
  • Mod is now driven via Airport CEO Mod loader, not UModFramework.
  • This update brought to you by the hard work of @humoresque

What is Tweaks?

Airport CEO Tweaks began largely as an experiment to see if modding was viable by tweaking the planner interface and editing “cargo” flights to have no passengers.

Tweaks is now moving towards becoming a total-overhaul mod, one system at a time. Systems revised so far include:

  • Flight Contracts: Flight contracts can and will renew if the airline is kept satisfied.
  • Routes: Routes now account for airline nationality, and generally are generated in a more realistic fashion.
  • Aircraft: A new data structure is laid onto aircraft types, allowing more information to be stored and used by other systems. This system also enables new aircraft types to be added.
  • Liveries: New tools are introduced to allow liveries to change all aspects of an aircraft’s appearance.
  • Turnaround Requirements: Turnaround requirements may vary based on airline or aircraft related factors, not just what is available. Turnaround duration may be varied based on airline or player requirements.
  • Airlines: Lots of definable factors influence the behavior of mod-added airlines, including home countries and presence of international services. This system orchestrates lots of the lower level features, and is subject to continued expansion.


This mod is installed and run via ACEO Mod Loader by @humoresque. You must install ACEO mod loader first in order to use the current version of Tweaks.

After ACEO Mod loader is installed to your AirportCEO directory, you may install my mod. manually or via steam.

Latest Download Link at Top Of This Post

UMF Version Archive

These outdated versions use the UMF [framework], not ACEO Mod loader, and are not compatible with the current framework.

Source Code

My source code is available here. (You do not need the source code to run the mod, it is made available for transparency.)

Bugs & Support

  • Please do report game-breaking bugs to this thread: there is every possibility that one got through.
  • Don’t report bugs encountered while playing with this mod enabled, or on a save that has had this mod enabled, to the developers unless it is reproducible without my mod ever being installed. Code-mods can become a pain for developers due to bugs in the mod being reported as bugs in the base game.

  • Keybinds Should be self-explanatory.
  • Cargo Airline Flags Airlines with any of these occurring in their name will be treated as cargo airlines.
  • Livery Author Log Files Turn these on if you’re a mod author trying to figure out why your livery isn’t working, or if I ask you to while we’re debugging.
  • Permissive Planning Makes planning flights very permissive and unrealistic; good for certain testing though.
  • Force Vanilla Turnaround Time Overrides new default turnaround times. May allow for auto-planner use, though this is still not formally supported

Current License: All rights reserved.

I am quite open to more permissive sharing, but you must ask me.

Each release/distribution shall revert to Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International 6 months by calendar date after it is made publicly available.

Each release/distribution shall revert to GNU General Public License 24 months by calendar date after it is made publicly available.

Major Changelog


  • Converted from UModFramework to ACEO Mod Loader


  • Added system for importing fully-new aircrafts.
  • Added data structure for new aircraft including placeholders for future functionality.
    • (New aircraft are available via separate workshop mod)
  • Added an as-of-yet unused system for dynamically rescaling aircraft.
    • Vanilla aircraft are not all to a uniform scale; this system can correct this
  • Added data structure for airline behavior modifications.
    • Functionality extends the existing airline.json file
    • Tag airlines as cargo-only
    • Tag airlines to operate only in home country(s)
    • Assign multiple home countries
    • Assign forbidden countries
    • Assign a different fleet of aircraft based on tweaks install status (useful for newly added aircraft)
    • (In Development: assign HUB IATA codes and max ranges from hubs, other hub rules)
  • Added data structure to save/load some additional data per each commercial flight.
    • Save/load utility is credit to humoresque
  • Replaced the flight types system with a more robust system.
    • (in the future may be user/modder-definable in json)
  • Reworked turnaround service progress tracking to take advantage of the ability to save and load data.
    • Hopefully fixed some bugs with stuck turnarounds and emergency flight turnarounds
    • Aircraft on small stands should not request services that are unavailable to them
  • Reworked turnaround time user-interaction and airline interaction.
    • Implements a new aircraft size rule set that will see increasing use in future
    • Consistent 5-minute jumps on mouse scroll
    • Minimum separation setting is respected
  • Subscribing to more than 50 workshop mods no longer causes mods beyond the 50 oldest to fail to load.
  • Patch to ensure cargo aircraft remain on stand now applies only to cargo aircraft.
  • Depreciated some old settings.
  • Re-factored and reorganized much of the code base.


  • Completely rewrote route generation.
  • New route generation supports airline nationality.
  • Resolved flight planning issue causing skipped flights and hanging confirmation button.
  • Implemented basic detection of domestic-only carriers.
  • Fixed Issues with airline contract descriptions
  • Fixed Issues with Tweaks aircraft shadows
  • credit humoresque: Tooltips in flight planner for hold-shift-to-affect-all functionality
  • credit humoresque: Structure auto-repair threshold now adjustable in F10 settings
  • credit humoresque: ACEO Tweaks version shown below game version


It is recommended to disable the auto planner when starting to play with 1.2.1, and enable it only cautiously, one stand at a time. The design goal of the update is that autoplanner is not necessary.

  • Turnaround times depend on type of flight
  • Airlines extend flight contracts when satisfied
  • Airlines cut short flight contracts when upset
  • Airlines operate various flight types based on their economic focus
  • Airline flight reward/bonus is now effected by flight & airline parameters
  • Some airline descriptions updated/retconned to match new game mechanics
  • Flight types displayed in flight info window, as well as expected PAX vs PAX capacity
  • PAX capacity depends on flight type
  • PAX load factor depends on time of day
  • Fixed some planner bugs from 1.1
  • Rewrote service request system for baggage, catering, cleaning, fueling, ramp service
  • Added setting to disable baggage service on small stands (vanilla behavior is default)
  • Added setting to disable baggage service on stands with no baggage bay (improved behavior is default)
  • Depreciated settings for experimental flight types and new contract lengths


  • Added a system for more complex airline and flight behavior. Partially utilized.
  • Turnaround time is player adjustable within limits
  • Airlines offer flight contracts which repeat based on airline size and satisfaction
  • Flights in series indicator in schedule UI now indicates flights remaining, as opposed to the total number planned initially, giving better indication of when contracts will expire.
  • Livery layers hidden by z-level are automatically unhidden (mod compatibility feature)
  • Further airline features disabled by default until 1.2.1 due to not being complete / stable.
  • Trello : Trello


  • Added “makewindow” command for active liveries
  • Added “xact” as shorthand for “exactly”
  • Made livery log-spam toggle-able


  • UMF auto-update enabled for future updates (pending approval from UMF)
  • Improved planner rescheduling logic: more permissive for the player
  • Added Flight type framework (not implemented)
  • Added Active Livery Components, used for changing previously inaccessible visual features of aircraft


  • Added basic cargo system
  • Added hold-shift planner enhancements
Previous Release Notes

Buy Me a Coffee?


Cool stuff! Maybe you can set something for us airline modders?

Feel free to make requests: one of my goals is to open up the possibilities for mods which don’t get into the game code as much as I can. For instance, when airlines get more “personality” the features will all be configurable via json or similar config format.

Wow… This is really getting serious. Amazing works, I’ll definitely check it out!

Also, this mod is incompatible with:

You could also add some of those features into your mod

Whoops; I meant to note the incompatibility in the main post.

I do intend to implement some crossover with that mod, though from a slightly (okay, radically) different angle.

Where negotiable turnaround time gives you more control over automatic and manual planning, my aim is to make there be less need for automatic planning by improving the manual planing experience. Airlines will have the direct control over turnaround time (those planes have places to be!) and the player will have indirect control by choosing contracts and flights that fit the needs/wants of the airport. I hope to create a game-play loop where a carefully constructed & optimized schedule is difficult to set up but easy to maintain.

On another note: I know that there will be interest in making these mods compatible. It is not feasible on my end. My technique of patching with the Harmony library is preferred in most unity-game modding communities for many reasons, including that it plays well with other harmony patches. The only way to be compatible with a mod like Negotiable Turnaround Time, which takes a more invasive approach to modifying the game code, is to maintain a completely separate version of the mod for this particular compatibility.

I will have a go at allowing the player to cycle between short/medium/long turnaround time settings for each flight type, but for now I’m not going to be doing surgery on the auto planner and it will be limited to flights with the default (vanilla) turnaround time.


1.0 Better Look-Alike Livery Support

formerly 1.1

  • All visual elements of an aircraft can be relocated or disabled
  • Livery elements can now be rendered on the shadow or lighting layer
  • Door locations, which define things like service vehicle locations, can be changed
  • All modifications work through the livery.json

This is a first iteration of this feature. Right now it should be possible to make most visual changes one would desire, but there are still no game play distinctions between a look-alike and its base-game aircraft counterpart. watch this space :wink:

Additionally, I have only tested these features, not developed content for them. Therefore if you aren’t planning on modifying livery’s yourself, you won’t see any effect of this change until and unless livery authors adopt it into their work.

Further Planner QOL

  • Manual planning mode now overrides player-set restrictions including the ability to plan on auto planned stands, the ability to plan on stands dedicated to a different airline, and the ability to plan at night on stands with night flights disabled, as long as night flights are researched.

Flight Activation Changes

  • Flights now calculate flight time based on speed and distance and activate when the aircraft should be taking off.
  • Rescheduling flights en-route is now related to flight time; you can delay flights by a percentage of total flight time plus a margin, you can advance flights by ~10 percent of remaining flight time

Really interesting to see where this goes…

First WIP of an A318 :smiley:


Yey the Baby bus! :smiley: I believe Air France is like the last European company to fly it. I would definitely want this in game!!! <3 <3

Air France and Tarom are the only (not Businessjet)-Airlines who operare it still


In preparation for the new airline mods to come out using this CBM, I created a “fake” workshop item that modders can mark required. It just says to download this mod w/ a link to the original post of this thread.
Modders how to use:

The item itself:


formerly 1.1.1

  • Added “makewindow” command for active liveries
  • Added “xact” as shorthand for “exactly”
  • Made livery log-spam toggle-able

I don’t know what is possible or whether you’re taking suggestions but…
I really want the small/medium/large flight filter on the flight planner to work at the contract level, so that I don’t have to hunt through every contract to find which ones have large flights available.

1 Like

Suggestions are great!

Thinking of my own experience… I completely agree. I’m actually working with code adjacent to that right now as I set up variable turn around times; if it’s an easy enough thing to add I’ll put it in the next update. If it’s difficult it will still go on the list for later.



Formerly 1.2.0

links & changelog in the main post… oh also there’s a Trello now

I originally planned a more ambitious update, but there are things that, while the technically work (sometimes)… they are not ready yet. This update contains play-adjustable turnaround times when scheduling manually, as well as the “unhide layers hidden by z-level” feature that a few livery authors were waiting on to ensure compatibility of look alikes that use this mod with unmodded installs. Airlines will also offer flight more directly on the basis of their satisfaction and size.

Everything below is not in 2.0; but is considerably closer to being realized given the groundwork that is in 2.0. Much of it is technically implemented, but is still to buggy to be enabled for general use… None of it is impossible.

What I’ve been working towards is really an overhaul of the flight planning game-play loop. The core concept is that your airport will be asked to handle several different types of flights with differing requirements. For example, commuter flights will demand a short turnaround time and prime hours, but reward you with extra bonus money. A high-class international flight will require extensive servicing on the ramp but may not be quite as picky about departing at rush hour. Cargo flights will typically ask to park for many hours, but don’t need almost anything from you during this time, and are happy to be scheduled at night when the passenger flights are in less demand.

To make the differing flight types feel a bit more authentic, they will be assigned by differing types of airlines. Crown talks big talk about being the most luxurious flight in the sky, so you won’t ever see their plane come though requesting a record breaking turnaround time and no catering. Likewise real airline mods should be able to simulate both budget carriers and VIP exclusive services.

Because there suddenly a lot more meaningful choices to be made about assigning aircraft to stands and flight times (think about a high-volume economy stand with many boarding desks vs a remote stand for cargo and contingencies), the auto-planner cannot be expected to keep up. That’s why I’m interested in making the manual planning experience a lot less tedious. Airlines will offer flight contracts which renew; growing in length to reflect their confidence in your services… or being canceled if you fail to meet the requirements you signed up for. If you do your job right and assign flights to times and stands that can satisfy their particular needs, those flights will continue to operate on your schedule (almost) indefinitely; or until its you who thinks its time to change course.


Hey, is there a discord server for this mod?
Also - is it possible to add flight crew like in sim airport and for the general aviation a pilot or something.

So just to clarify, this won’t conflict with other mods other than the Negotiable Turnaround Time and Autoplanner settings mod, right? Also, will this mod run at all times while ingame, or just when activated. Thanks!

Afaik those are the only two other published script mods for this game. All other “mods” are actually just contracts with skins and/or logos. Those won’t have a conflict.

Hey, is there a discord server for this mod?

@t1a2l I am on discord and am particularly active in the ACEO modding group discord. A dedicated discord is a “maybe one day” but feel free to reach out.

Also - is it possible to add flight crew like in sim airport and for the general aviation a pilot or something.

It is something I’ve thought about and think would be neat. Right now I’m prioritizing features that change how the game plays in terms of player decisions. For now, there are a lot of things that would take less effort to make happen and add more to the experience of playing the game. As I build my competence reworking the game’s systems there may come a time when I decide to do this as a side project, but it definitely won’t be for a while, and I can’t commit to it.

So just to clarify, this won’t conflict with other mods other than the Negotiable Turnaround Time and Autoplanner settings mod, right?

@ATS_guy andyc is correct that all airline/business mods will work fine; the only place where I interact with these is in making new features optionally available to them.

Also, will this mod run at all times while ingame, or just when activated. Thanks!

The mod will run only when activated. The default behavior after installing is that the mod is activated, but deactivating it lets you play without the mod without having to manually uninstall. I’d mostly expect this to be useful later on in development once the game-play balance is significantly altered by my mod.

I had to do a manual download, because of some issues with normally downloading it, even though I’m on PC. I have downloaded it but how to I put it in the game now, (since I did a manual download.)