Creating a Chemtrail aircraft

The following tutorial will help you creating an aircraft type that will trail gas behind it when its target is within range. The gas can be Chaos gas or traditional toxic gas. In fact, ANY type of weapon can be trail-fired behind aircraft, but it makes most sense with gas. The following technique works in both TS and RA2/YR.

If you intend to use this for creating toxic gas in RA2/YR, first thing I have to tell you that this tutorial will presume that you have fixed, or know how to fix, the GasCloudSys. Then, make yourself an aircraft. Stats don't really matter, but it needs to have the following weapon:

[ChemtrailWeapon]
...
Warhead=Gas ; This is for traditional toxic gas
Projectile=ChemtrailProjectile
Range=5 ; whatever you like, but as a rule of thumb, it should be similar to [Bomb]'s range.
          so it doesn't look ridiculous...
...

Now the projectile, which does the trick: (It should not have a ROT - best clone it from [Cannon2])

[ChemtrailP]
...
Dropping=yes ; !!!!!!!
...

Traditionally, it is held that the Dropping tag is buggy and has no desirable effect since Red Alert, because all it does is delete a weapon's projectile immedeately after it has been created. But, in a twist, that will be exactly what makes the weapon "dropping" here: The projectile is deleted while still in the air, at the location of the aircraft. The warhead detonates. The gas is spawned. The gas will slowly sink to the ground after the aircraft has passed by.