How do you test missions you are making

[Gunfreak]

In DCS this is easy, but how in IL2, I'm buidling a ground battle, with units firing at ground points, and I want to test if those units actual fire, or if something is off. But how do I test it? 
Missions can't seem to start without a player aircraft linked to mission start?

[Jaegermeister]

Correct. Place a plane on the ground in the mission. Select "Player" in the advanced properties. After you start the mission, you can use external cameras to view the linked entities in the mission