I currently have four checkride failures all from GA. I failed my initial Private, Private multi add on, and my CFI single add on twice. That last one regarding my CFI was, as stated, not my initial. I passed my initial CFI the first time. I did the checkride as an MEI applicant. However, after obtaining my MEI, I ended up failing the single engine add on to my CFI twice. I am currently working as a FO at a Part 135 cargo company in a twin turbine aircraft and I didn't fail the training program. My plan is to become a captain and gain some twin turbine PIC. Overall, my question is could I still get hired at a regional like EDV or one of the AA wholly owneds with these credentials and past training record? What are my chances of getting on with a major like Delta? I know that four failures is a lot however I am wondering if I still might have a chance at a good regional or even any major. Thank you in advance to any who respond