Delayed Spawn
 

How do you get planes to spawn a certain amount of time after the map starts?

I know I have seen the answer a long time ago but I can not find it now.

Spawn script on?
Custom script?
Trigger?
Action?

1. Select the plane group in fmb.
2. Tick the "spawn on script" checkbox at the bottom of the plane properties tab.
3. Go to the tiggers in the script menu & create a new timed trigger (this is where you specify how much time before spawning)
4. Go to the 'actions' tab in the script menu & create a new action. Select 'airspawngroup' & click on the group you want to spawn.

The only choice I see under action type is an"air spawn group".
Is there a ground spawn?