what prevents AI planes from flying?

My first attempt at putting in AI worked fine.
I did an SR71, a Mustang and an F15. I did a couple of the default planes too.
I started having trouble when putting in an A380 repaint I was working on. It wouldn't appear at NZAA (departure airport.). Even tho I followed the same method that worked with the previous successful attempts. I also tried a Qantas 747 that didn't work.
What I have been doing is this.
Use Ttools to decompile traffic.bgl.
Use text editor to add in the new aircraft into aircraft*.bgl.
Use simple AI to make a flightplan using the new aircraft (eg AC#65)
recompile everything back to bgl files.
there might be something totally obvious (to you!) that I'm missing. But damned if i know what it might be. I've done lots of forum reading.. but nothing I've read really points the finger.
I do have a question tho... what the second field in a aircraft line represent ?
its like 505 for a 747, only 120 for a Cessna.
eg "AC#43,505,"Qantas Airways B747-438"
I did an SR71, a Mustang and an F15. I did a couple of the default planes too.
I started having trouble when putting in an A380 repaint I was working on. It wouldn't appear at NZAA (departure airport.). Even tho I followed the same method that worked with the previous successful attempts. I also tried a Qantas 747 that didn't work.
What I have been doing is this.
Use Ttools to decompile traffic.bgl.
Use text editor to add in the new aircraft into aircraft*.bgl.
Use simple AI to make a flightplan using the new aircraft (eg AC#65)
recompile everything back to bgl files.
there might be something totally obvious (to you!) that I'm missing. But damned if i know what it might be. I've done lots of forum reading.. but nothing I've read really points the finger.
I do have a question tho... what the second field in a aircraft line represent ?
its like 505 for a 747, only 120 for a Cessna.
eg "AC#43,505,"Qantas Airways B747-438"