It is possible to eliminate the fire arrow special ability. Some smarter person probably already has this figured out, but it stumped me when I first tried.

In the past I've been annoyed by the AI's penchant to shoot fire arrows at infantry, cavalry, birds flying by, etc. Unfortunately, the fire arrow special ability is tied to foot archers and is not directly modifiable as a unit stat as best I can tell. However, the HA bug led me to revisit the problem. I tried using the "thrown" attribute for archers as we did with HA's, but that didn't eliminate fire arrows. So next I tried the following edit for Roman Archers in the export_descr_units.txt file:

Original:
stat_pri 7, 2, arrow, 120, 30, missile, archery, piercing, none, 25 ,1

Altered:
stat_pri 7, 2, javelin, 120, 30, missile, archery, piercing, none, 25 ,1

This worked! The fire arrow special ability was gone. However, this had the drawback of 1) the projectile being a javelin 2) The arc and range are reduced because the javelin has a different trajectory.

After this success, I decided to try something in descr_projectile_new.txt

What I did was to copy the whole entry for "projectile arrow" and place this copy at the bottom of the page. I then changed this copied section's name to:

projectile arrow2

After this I went back to my Roman Archers and changed their stats to:

stat_pri 7, 2, arrow2, 120, 30, missile, archery, piercing, none, 25 ,1

Initial tests indicate that this is working without crashing the game, etc. The archers appear to behave normally, but no longer have the fire arrow special ability. I need to do some more testing and see if it interferes with anything, such as AI deployment, etc.

If anyone notices a problem with this, please post it. Thanks!