It has been a while but I'll try to explain. You train your schval on a distant piece of ground. Lock that ground in schval. Up on the upper left control panel where you assign targets, there is a button for ingress point. You hit that. There is now an ingress point on the abris. Remember to reset the abris so it takes. Now, find targets, assign targets to a wingman. Assign ingress point to wingman. Tell wingman to go to ingress point.
Before last patch, you could do this and he would fly to ingress point and then attack assigned targets from that point. He no longer does that as mentioned before.
There was a producer note from Matt which showed this. I'll have to take a look at which one and get back to you. I hope this helps.