Edited 7 years ago by SavageCDN
This has been an issue since Day One with AI pilots not being able to figure out runways... some maps seem to be better than others. My only suggestion is to make sure the runway is clear of any and all objects, units and animals.
In the A2 days there was a script called ATCRabbit - all it did was spawn in a rabbit on the runway to block planes taking off as the AI pilots refused to run them over!