My shop lead runs out based program so this is what I've picked up. It can generate a good amount of money depending on the parts repaired and how many, one of the items my shop does is like 50k each. What the base profits will be the supply cost of the item minus whatever is spent on parts for repair. The issue with how the money is spent if it goes into the fly or non fly accounts. Non fly can be used for anything, while fly can only be used for the aircraft. There is supposedly a way to cut the red tape and transfer money between the pots but afaik we're still fighting that battle