My suggestion is this:
Reduce the time it takes to repair and/or recover downed planes based on idle workers.
I personally don't mind the recovery time of planes, since their asses have to get dragged back to base but the repair time on planes is just ridiculous. With my 45 workers in 3 workshops i can build a MIG in a little over a day, but when I wish to repair a downed MIG or F16 for that matter, it takes up to 3 days.
My solution would be to reduce the time a plane needs to be repaired based on the amount of idle workers currently not working on a project.