I seriously doubt that UAL had any idea regarding the forth coming 737 or DC9 that appeared on the scene in the mid to late 60's. ALPA on the other hand was demanding 3 pilots on the flight deck of all jet transports and that is how the professional FE's job started it's downhill slide. UAL was probably one of the first operators to hire pilots first and train them for FE duties. There is a lot more to this story but needless to say it was not very pretty.