1 Information
AI Helicopter Glitch refers to the instances of various types of unresponsive and anomalous AI helicopter behaviours which are common occurrences on modern computer hardware (CPU) models regardless of the operating systems. Fortunately, the issue has been extensively researched and it is also quite easy to fix via multiple methods.
This problem only occurs in the original Urban Assault game engine. The symptoms of the AI helicopter glitch only started to appear after the official support for the game had been already ended, so there was no official fix or patch created from the developers.
OpenUA (UA:Source) engine does not have this problem anymore since it is already fixed by default.
2 Overview
2.1 Signs & Symptoms
AI Helicopters do not obey orders, have problems with turning, and cannot track or follow enemies properly. They are often unable to move to directions other than upward, and when ordered to move they will uncontrollably gain or lose altitude at the spot. The issue only affects the AI-controlled helicopters and does not affect the performance of helicopters under the direct first-person control mode of the player.
2.2 Technical Cause
The AI helicopter glitch problem is caused by an obsolete threshold check in the code that processes helicopter rotations inside the AI layers. When an update time period (via delta-time algorithm) of frame ticks for rendering the display become sufficiently short, which happens on new, modern CPU models, the mathematical condition is never fulfilled and the AI helicopter rotation calculation is not processed correctly.
2.3 Workarounds
Various workarounds exist to mitigate the problem; but only one method is recommended nowadays. See the Solution section below.
3 Solution
3.1 Applying the updated game executables fix/patch
A new modern Helicopter Patch with the updated game executable files was created. This patch is flawless and has no drawback unlike the other old workarounds. It should provide a definitive solution to the problem once and for all.
The download link for Helicopter Patch file can be found below. Before installing the patch, check the Readme file first.
3.2 Download Link for Helicopter Patch
4 Important Note
Disclaimer Warning: If you are still using any kind of unverified 'helicopter patch' files sourced from uncertain origins that were made before 2016, specifically any type of 'patch mods' that are designed to directly alter/modify/replace the *.scr data (script) files in the game's 'Data\Scripts' folder, then please remove those files from your machines completely as soon as possible!
This kind of outdated custom patch files will never work correctly on modern hardware, but they will still detrimentally change the original helicopter data and properties in many unexpected (and often undesirable) ways, which will significantly impair the physics and performances of the affected helicopters.
Moreover, since such contents are technically modified game data, the game engine will detect those files and trigger the file mismatch warning as a potential sign of cheating on multiplayer matches. Therefore please delete any outdated patch files beforehand!
If you are uncertain whether your game files contain any undesirable modified helicopter data or not, the new Helicopter Patch file also contains the fully original and default game data files; which you can apply inside the game folder.
5 Historical Methods
There were several legacy makeshift methods used to circumvent the helicopter bug. However, since the new Helicopter Patch offers the complete solution without any drawbacks, they have been removed to avoid confusions for now.