Yeah, the combination of different type ratings with different pay rates (and different bases) and the seniority system creates a truly hellish training load when you are forced to furlough or return pilots from furlough. That’s one of the reasons Boeing came up with the dual 757/767 type rating to begin with. I’m not sure why Boeing abandoned that concept but Airbus sure picked it up and ran with it - in fact raised it to an even higher standard with their A320 ‘family’ allowing you to fly anything from A319/320/321CEOs all the way through A319/320/321NEOs and 321LRs and 321XLRs on the same type, with relatively minimum differences trading for 330s and 350s. And a multiple type fleet is also expensive for maintainers, both in terms of parts and maintaining experience on the specific fleet type.



The single fleet-type airlines like SWA, NK, and F9 have a huge advantage over AA, UA, and DL in this regard, and the former do seem to now be realizing that. The fact that a year “x” pilot on any of the aircraft can be assigned to any aircraft in the fleet but gets the same pay regardless is also a huge help, since bidding to a different aircraft type (assuming there were any) for more money causes a lot of expense in training as well, short term equipment locks notwithstanding.

But you are right, it is a long and costly process. And it will continue to hinder the three biggest legacies well into the time that the single fleet airlines are recovering. Especially AA which has furloughed.