Well, here's the difference, apparently. At AA, FOs and IROs bid their own separate lines, with FO lines going more senior. Hence the seniority issue. However, there are many CAs/FOs who offer the landing to the IRO. But most IROs gladly take the 3 sim landings every three months because we get paid an extra 5 hours to go to school. Not a bad deal.

I guess at DL, you guys only bid FO lines, and it is sorted out at departure.

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