It’s not just that pilots didn’t need new training, because they were still supposed to have some minimal training on the changes.
Pilots can only hold one type certification at a time, and have to retrain to switch between them. Southwest pretty much only flies 737’s and is heavily interested in the MAX because it means they don’t lose the ability for pilots to fly their other aircraft due to retaining the same type certification.
Pilots can hold more than one type certification, but they have to keep them current. There are many pilots who fly more than one type of aircraft routinely.
Boeing tried so hard to avoid "retraining". Yet the training isn't that expensive. It's about $22,000 for an airline pilot to move from another aircraft to a 737 family aircraft. Takes about a month. And that's like an Airbus to a Boeing switch, not just between similar models. If Boeing threw in a few training credits with each aircraft (each costs about $100 million) that would have solved the problem.
> Pilots can only hold one type certification at a time
Source? I am pretty sure pilots could hold any number of type ratings (sic) at any time, but it's uneconomical for the airline to keep them rated (and current), so it's rarely done.
Pilots can only hold one type certification at a time, and have to retrain to switch between them. Southwest pretty much only flies 737’s and is heavily interested in the MAX because it means they don’t lose the ability for pilots to fly their other aircraft due to retaining the same type certification.