Trigger for wingman to join later???

[MikeSinn]

I'm just beginning to dabble in with the mission editor and had a question regarding controlling your wingman.

 

I'm working on a simple scenario where I want the player to take off and perform a specific task. Once complete and factoring in a random variable, I would want the wingman (still at base) to spool up, take off and join the player for the remainder of the mission. Any of you expert mission builders have a suggestion on how best to accomplish this? Any help or ideas would be greatly appreciated.